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A series of new wholly aromatic (co)polyesters based on m-substituted bifunctional comonomers—4′-hydroxybiphenyl-3-carboxylic (3HBCA) and 3-hydroxybenzoic (3HBA) acids with molar ratios of 3HBCA:3HBA from 0:100 to 60:40, respectively—was synthesized. NMR and FTIR spectroscopy methods proved the full compliance of the copolymer composition with the target ratio of comonomers, as well as high compositional homogeneity (absence of block sequences). The resulting copolyesters have a sufficiently high molecular weight and their intrinsic viscosity values are in the range of 0.6–0.8 dL/g. Thermal analysis showed that all 3HBCA-3HBA copolyesters are amorphous, and with an increase in the content of biphenyl units (3HBCA), the glass transition temperature increases significantly (up to 190 °C). The onset of the intense thermal decomposition of the synthesized polyesters occurs above 450 °C. Thus, this indicates a sufficiently high thermal stability of these polyesters. Rheological measurements have shown that melts of copolyesters with a high content of 3HBCA units exhibit anisotropic properties. At the same time, the method of polarization optical microscopy did not confirm the transition to the liquid crystal state for these polyesters. These results confirm that it is possible to obtain high-performance polyesters based on 3HBCA, but not a mesogenic comonomer. Thus, 3HBCA is a promising comonomer for the synthesis of new thermotropic copolyesters with controlled anisotropic properties. [ABSTRACT FROM AUTHOR]

PCL-based biodegradable shape-memory polymers (SMPs) are limited in strength, which restricts their practical applications. In this study, a series of novel SMPs, composed of poly(ethylene terephthalate) (PET), poly(ethylene naphthalate) (PEN), and poly(ε-caprolactone) (PCL), were synthesized and cross-linked using planar (benzene-1,3,5-tricarboxylic acid, BTC) or non-planar (glycerol, GC) cross-linkers via the one-pot method. The influence of different kinds of cross-linkers and hard segments of copolyesters on the thermal properties, crystallization behavior, mechanical properties, shape-memory performance, and degradability was investigated by FT-IR, 1H-NMR, DSC, DMA, TGA, XRD, tensile test, intrinsic viscosity measurement, and in vitro enzymatic degradation test. The results indicate that the tensile strength of the copolyester can be significantly improved from 27.8 to 53.2 MPa by partially replacing PET with PEN while maintaining its shape-memory characteristics. Moreover, a small amount of cross-linking modification leads to higher temperature sensitivity, improved shape recovery rate at third round (Rr(3) = 99.1%), and biodegradability in the cross-linked PET/PEN/PCL shape-memory polymers. By changing the crystallization morphology and cross-linking forms of the material, we have developed a shape-memory polymer with both high strength and a high shape recovery rate, which provides a new strategy for the development of shape-memory materials. [ABSTRACT FROM AUTHOR]

A systematic study was performed on the dynamic viscoelastic properties of N-methylpyrrolidone (NMP) solutions of poly(vinylidene fluoride) (PVDF) samples with a wide range of weight average molar masses (Mw) from 140 to 3300 kg mol−1 over a temperature range of −24 to 35 °C in the dilute to semidilute concentration (c) regime in this study. In previous studies under extremely dilute conditions, it was confirmed that PVDF molecules behave as isolated highly elongated rigid rods, and the average particle length (⟨L⟩) and diameter (⟨d⟩) for different PVDF samples were precisely determined. The fundamental viscoelastic parameters used to analyze the dynamics of PVDF molecules dissolved in NMP were precisely determined, including the zero-shear shear viscosity (η0), the steady state compliance (Je), the average relaxation time (τw), and the activation energy (E*v) of τw in this study. E*v increased stepwise above c values corresponding to the reciprocal of the intrinsic viscosity ([η]−1) for different solutions, independent of Mw, showing that contact or the formation of entanglements between PVDF molecules causes the increase in E*v. Je−1 was found to be proportional to the number density of PVDF molecules (ν = cNAMw−1, where NA denotes the Avogadro constant) over the entire investigated v range, irrespective of Mw and the presence of entanglements between PVDF molecules. The reduced specific viscosities, ηspNA⟨L⟩3(Mw[η])−1, were reasonably described as a universal function in the parameter ν⟨L⟩3 over the entire investigated range, and ηspNA⟨L⟩3(Mw[η])−1 ∝ (ν⟨L⟩3)3 was found over the region 102 < ν⟨L⟩3 < 103, irrespective of Mw. [ABSTRACT FROM AUTHOR]

Polyamidine, which is an excellent flocculant, was prepared by a two-step process: the copolymerization of N-vinyl formamide (NVF) and acrylonitrile (AN) and the amidinization of the copolymer. The existing methods of copolymerization have many drawbacks such as high molecular weight loss during amidinization, environmental pollution, and high cost. We propose the use of pure water as the reaction medium for the dispersion polymerization of NVF and AN to overcome these shortcomings. The products of dispersion polymerization have great fluidity. Aqueous dispersions also help to reduce the amidinization time and molecular weight loss during amidinization, which effectively improves the charge density of polyamidine. The effects of polymerization temperature and monomer concentration on particle size and intrinsic viscosity were studied. The copolymer was processed to produce polyamidine under acidic conditions, and the influence of the reaction conditions on charge density was investigated. Compared with those of solution polymerization, the copolymer products of dispersion polymerization exhibit higher amidinization rate, charge density, and flocculation performance. [ABSTRACT FROM AUTHOR]

Microbiological contamination of cinematographic films can cause damage and loss of image information. A large part of the films is made with the base of cellulose triacetate, which has been used from the 1940s until today. Cellulose triacetate is relatively resistant to common organic solvents, but some types of microorganisms can contribute to its faster degradation. In this work, we tested four types of disinfectants suitable for mass disinfection and sufficiently effective against various types of microorganisms. Butanol vapours, a commercial mixture of alcohols (Bacillol® AF), Septonex® (an aqueous solution of [1-(ethoxycarbonyl)pentadecyl] trimethylammonium bromide) and ethylene oxide applied as a gas mixed with carbon dioxide were tested. Samples of a commercial film made of cellulose triacetate were disinfected. The samples were aged for 56 days at 70 °C and 55% RH. Changes in optical, mechanical and chemical properties were studied. None of the disinfectants affected the change in the degree of substitution. For samples disinfected with Bacillol® AF (alcohol mixture), part of the plasticiser (triphenyl phosphate) was extracted and the intrinsic viscosity of the cellulose triacetate solution was reduced after ageing. A slight decrease in intrinsic viscosity also occurred after disinfection with ethylene oxide. Compared to the non-disinfected samples, butanol vapours and Septonex® appear to be the most gentle disinfectants for the cellulose triacetate film base, within the studied parameters. [ABSTRACT FROM AUTHOR]

Titanates are widely used in the synthesis of polyesters, such as Poly (butylene succinate) (PBS), due to their excellent catalytic activity for polycondensation. However, the hydrolysis sensitivity of titanate and side reactions at high temperatures restrict the further improvement of the molecular weight of polyesters and lead to the high content of end carboxyl group content in the products. In this work, we prepared titania–silica composite aerogels with resistance to hydrolysis and large specific surface area, which were further explored as an efficient catalyst for polycondensation reactions. A series of titania–silica composite aerogel catalysts for PBS polycondensation were successfully prepared by the sol-gel method. The influence of a Ti/Si ratio on the surface morphology and structure of the aerogels was examined. Titania–silica composite aerogel exhibits the surface characteristics of high specific surface area and high Lewis acid content. The specific surface area of titania–silica composite aerogels can reach 524.59 m2/g, and the Lewis acid content on the surface can reach 370.29 μmol/g. Furthermore, the catalytic performance for the polycondensation reaction of PBS was investigated. The intrinsic viscosity of PBS synthesized by catalysis with the composite catalyst with a Ti/Si ratio of 9/1 reaches 1.74 dL/g, with the Mn of 7.72 × 104 g/mol. The hydrolysis resistance stability of the titania–silica composite aerogel is greatly improved compared with traditional tetrabutyl titanate (TBT), and the end carboxyl group content of PBS is effectively reduced to lower than 30 mol/ton. [ABSTRACT FROM AUTHOR]

A series of poly(benzimidazole sulfone)s (PBSs) and poly(benzimidazole ketone)s (PBKs) containing 5,6‐dimethoxy‐1,3‐dihydro‐2H‐benzo[d]imidazol‐2‐one (MBIO) have been synthesized by C–N/C–O coupling with different percentages of three other diphenol monomers under similar conditions. The structure of PBS‐MBs and PBK‐MBs was confirmed using 1H NMR and Fourier transform infrared spectroscopies, and X‐ray diffraction data revealed that all the polymers are in an amorphous state. Due to the introduction of methoxy, the polymers were more soluble in common aprotic polar solvents. The intrinsic viscosity of the synthesized polymers was measured with an Ubbelohde viscometer, ranging from 0.38 to 1.35 dL g−1. The MBIO‐based polymers have a remarkably good thermal stability with a high glass transition temperature of up to 305.1 °C. Furthermore, the wavelength of maximum fluorescence emission from homopolymers is around 414 nm with emission of blue light in N‐methyl‐2‐pyrrolidone solution (1 mg L−1) and around 530 nm in films. They also showed low dielectric constants (κ = 2.60–3.10 at 1 MHz) and low water absorption (0.22–0.58%). It was encouraging to discover that these polymers have potential utility for the microelectronics industry, in which good solubility facilitates processing and molding, excellent thermal stability allows devices to be used under harsh conditions, low water absorption prevents device expansion and shrinkage and low dielectric constant is desired to prevent crosstalk between conducting paths. © 2023 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

Bacterial biofilms are surface-attached communities that are difficult to eradicate due to a high tolerance to antimicrobial agents. The use of non-biocidal surface-active compounds to prevent the initial adhesion and aggregation of bacterial pathogens is a promising alternative to antibiotic treatments and several antibiofilm compounds have been identified, including some capsular polysaccharides released by various bacteria. However, the lack of chemical and mechanistic understanding of the activity of these polymers limits their use to control biofilm formation. Here, we screen a collection of 31 purified capsular polysaccharides and first identify seven new compounds with non-biocidal activity against Escherichia coli and/or Staphylococcus aureus biofilms. We measure and theoretically interpret the electrophoretic mobility of a subset of 21 capsular polysaccharides under applied electric field conditions, and we show that active and inactive polysaccharide polymers display distinct electrokinetic properties and that all active macromolecules share high intrinsic viscosity features. Despite the lack of specific molecular motif associated with antibiofilm properties, the use of criteria including high density of electrostatic charges and permeability to fluid flow enables us to identify two additional capsular polysaccharides with broad-spectrum antibiofilm activity. Our study therefore provides insights into key biophysical properties discriminating active from inactive polysaccharides. The characterization of a distinct electrokinetic signature associated with antibiofilm activity opens new perspectives to identify or engineer non-biocidal surface-active macromolecules to control biofilm formation in medical and industrial settings. Bacteria produce several high molecular weight polysaccharides with ill-defined anti-adhesion properties. Here, the authors identified key molecular and biophysical determinants of active antibiofilm polysaccharides, opening new perspectives to identify or engineer new compounds able to control bacterial adhesion and biofilm formation. [ABSTRACT FROM AUTHOR]

Dietary carbohydrates are unexploited in the by-products of economically valuable Phyllostachys pracecox bamboo shoots. A residue-derived polysaccharide (PBSR1) was aqueously extracted from the processing waste of this bamboo shoot species. Its primary structure and advanced conformation were elucidated by a combined analysis of spectroscopy, chromatography, 2D nuclear magnetic resonance, laser light scattering and atomic microscopy. The results indicated PBSR1 was a triple-helix galactan consisting of →6)-β-D-Galp and →3)-β-D-Galp in linear with an 863 KD molecular weight (Mw). The relationship between the radius of gyration (Rg) and intrinsic viscosity ([η]) on Mw were established as Rg = 1.95 × 10−2Mw0.52±0.03 (nm) and [η] = 9.04 × 10−1Mw0.56±0.02 (mL/g) for PBSR1 in saline solution at 25 °C, which indicated it adopted a triple-helix chain shape with a height of 1.60 ± 0.12 nm supported by a red shift of λmax in Congo red analysis. The thermodynamic test (TG) displayed that it had excellent thermal stability for the food industry. Further, those unique structure features furnish PBSR1 on antioxidation with EC50 of 0.65 mg/mL on DPPH· and an ORAC value of 329.46 ± 12.1 μmol TE/g. It also possessed pronounced immunostimulation by up-regulating pro-inflammatory signals including NO, IL-6, TNF-α and IL-1β in murine cells. Our studies provided substantial data for the high-valued application of residues and a better understanding of the structure–function relationship of polysaccharide. [ABSTRACT FROM AUTHOR]

Ultrasound pretreatment and microwave-assisted extraction (MAE) techniques were used to extract pectin from watermelon rind. This work investigated the effect of the power and time of pretreatment on the yield and characteristics of the extracted pectin. Imaging studies showed that ultrasonic pretreatment changed the morphology of the raw powder, leading to a greater porosity, and facilitated the extraction process. The highest extraction yield of pectin was 19.08% (w/w), for 5 min of extraction at 500 W ultrasonic pretreatment. Ultrasonic pretreatment affected the degree of esterification and the galacturonic acid content of pectin. The galacturonic acid content of all samples was higher than 69.0%. Extraction pretreatment reduced the surface tension value of the aqueous solution of pectin and affected the foam capacity of pectin and its monosaccharidic composition. The ultrasonic pretreatment caused significant changes in pectin characteristics, such as intrinsic viscosity, viscosity average, molecular weight, ratio of homogalacturonan to rhamnogalacturonan and the water holding capacity. In addition, kinetic studies showed that a kinetic empirical model adequately describes the effect of ultrasonic pretreatment on foam stability and its half-time. [ABSTRACT FROM AUTHOR]

A series of bisphenols, 4,4′‐sulfobisphenol (BPS)/2,2‐bis(4‐hydroxyphenyl)butane (BPB) co‐polyarylates with amorphous structures were synthesized from two BPS and BPB, and two different structures of benzoyl chloride monomers. The results of DFT calculations showed that the reaction activation energy of BPB with isophthaloyl chloride (IPC) and terephthaloyl chloride (TPC) was 8.05–8.40 Kcal/mol. The reaction activation energy of BPS with IPC and TPC was 38.73–39.09 Kcal/mol. GPC test results were consistent with theoretical calculations with BPS content from 0% to 15% resulting in a copolymer Mn of 22,000–11,600 and a Mw of 46,100–34,800. The intrinsic viscosity of co‐polyarylates ranged from 0.55 to 0.71 dL/g. The glass transition temperature (Tg) and 5% thermal weight loss of the co‐polyarylates were 179.3–205.4 °C and 461.4–487.8 °C, respectively. Improved solubility of co‐polyarylates in polar solvents. At the same time, the introduction of BPS did not result in any loss of mechanical properties, with Young's modulus in the range of 1444.32–1870.45 MPa, elongation at break in the range of 23.7%–30.8%, and tensile strength in the range of 52.21–59.38 MPa. [ABSTRACT FROM AUTHOR]

Cationic polyacrylamide (CPAM) is a commonly used flocculant for water treatment. The main factors affecting its flocculation performance are cationic degree and intrinsic viscosity. This study was to improve the intrinsic viscosity and cationic degree of CPAM, sodium polyacrylate was selected as the template (T), and dimethyldiallylammonium chloride (DMD) and acrylamide (AM) were used as monomers to prepare a Novel cationic polyacrylamide (TPDA) with ultraviolet (UV)-initiated template polymerization. First, single-factor tests were conducted to screen the factors that had significant effects on TPDA intrinsic viscosity, and then response surface methodology (RSM) tests were conducted using the selected factors to obtain the optimal polymerization conditions. The results showed that the addition of template increased the cationic degree of TPDA, and decreased its intrinsic viscosity. there were three factors that significantly affected TPDA intrinsic viscosity, and the order of significance was the initiator concentration, monomer mass fraction and pH. A model that could guide the TPDA polymerization was obtained by RSM tests. The results of model optimization showed that the optimal conditions for TPDA polymerization were as follows: the monomer mass fraction, pH value, concentration of photoinitiator (V-50), mass fraction of urea and n(T):n(DMD):n(AM) in the polymerization solution were 27.1%, 7.2, 0.47‰, 0.3%, 3:3:7, respectively, and the ultraviolet irradiation time of 70 min, and the intrinsic viscosity of the obtained TPDA was.10.98 dL/g. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

At present, the development and usage of degradable plastics instead of traditional plastics is an effective way to solve the pollution of marine microplastics. Poly (butylene adipate-co-terephthalate) (PBAT) is known as one of the most promising biodegradable materials. Nevertheless, the degradation rate of PBAT in water environment is slow. In this work, we successfully prepared four kinds of high molecular weight polyester copolyesters (PBATGA) via quaternary copolymerization. The results showed that the intrinsic viscosity of PBATGA copolymers ranged from 0.74 to 1.01 dL/g with a glycolic acid content of 0–40%. PBATGA copolymers had excellent flexibility and thermal stability. The tensile strength was 5~40 MPa, the elongation at break was greater than 460%, especially the elongation at break of PBATGA10 at 1235%, and the thermal decomposition temperature of PBATGA copolyesters was higher than 375 °C. It was found that PBATGA copolyester had a faster hydrolysis rate than PBAT, and the weight loss of PBATGA copolymers showed a tendency of pH = 12 > Lipase ≈ pH = 7 > pH = 2. The quaternary polymerization of PBAT will have the advantage of achieving industrialization, unlike the previous polymerization process. In addition, the polymerization of PBATGA copolyesters not only utilizes the by-products of the coal chemical industry, but also it can be promising in the production of biodegradable packaging to reduce marine plastic pollution. [ABSTRACT FROM AUTHOR]

Abstract Background In the present study, the effects of NaCl and CaCl2 (0–200 mM) on the rheological properties of Lepidium perfoliatum seed gum (LPSG) as a novel potential source of hydrocolloid were investigated. Sugar composition and FTIR analysis were measured to supply more structural information. Results The results illustrated that LPSG had small amounts of uronic acids (6.65%) and it is likely an arabinoxylan-type polysaccharide (it has 44.66% and 31.99% xylose and arabinose, respectively). The FTIR spectra also revealed that LPSG behaved like a typical polyelectrolyte due to the presence of carboxyl and hydroxyl groups. It was observed that the gum solutions exhibited viscoelastic properties in the presence of NaCl and CaCl2 salts. The tan δ values for all samples were less than 1 but greater than 0.1, exposing the weak gel-like behavior at different ion types and ionic strengths. With increasing salts concentrations, the limiting values of strain mostly increased due to the interchain interactions (from 1.46 to 4.61 and from 0.99 to 2.13 for NaCl and CaCl2, respectively). Therefore, the addition of salts increased the stiffness of mucilage solutions in the concentrated regime. The results of frequency sweep tests revealed that storage and loss moduli were increased with increasing ion concentration. This effect was more pronounced for LPSG solutions containing Ca2+. Among various models, the model of Higiro1 showed a higher efficiency to evaluate the intrinsic viscosity of LPSG for all co-solutes (R2 ≥ 0.98). With increasing the concentration of salts, the intrinsic viscosity of LPSG decreased. Calcium ions had a more diminution effect on intrinsic viscosity than sodium ions. Conclusions Trying to adjust the salt concentration could modify the rheological properties of food products. Because food contains a variety of additives, further research should look into the rheological properties of LPSG at different pHs, as well as the presence of other salts and sugars often employed in the food industry. LPSG has the potential to be used in biomedical, pharmaceutical, food industries, tissue engineering, and cosmetic applications due to its biocompatibility, rheological properties, and antioxidant activities. Graphical Abstract

The research focuses on the characterization and evaluation of drug delivery efficiency of a microwave-assisted, free-radical synthesized polyacrylamide-grafted Assam Bora rice starch (ABRS) graft copolymer (ABRS-g-PAM). Percentage grafting efficiency (% GE) and intrinsic viscosity were chosen as the optimization parameters. The optimized ABRS-g-PAM Grade Formulation 4 (GF4) was found to be the best grade. GF4 was characterized through XRD, FTIR, TGA, DSC, and 1³C NMR, confirming efficient polyacrylamide grafting onto ABRS, besides swelling studies. SEM and FESEM showed a rough GF4 surface. Further analysis using Atomic Force Microscopy (AFM) detailed the irregular, rough internal architecture. The maximum swelling of GF4 occurred at pH 7 and 0.005 (M) NaCl, demonstrating second-order swelling kinetics. The soil biodegradability study of GF4 confirmed its biocompatibility. In vitro drug release studies showed that GF4 achieved 99 % release of Rosuvastatin over 26 h, thereby supporting the controlled release behaviour of the optimized polymer. [Display omitted] • Polyacrylamide grafted Assam Bora rice starch graft copolymer was synthesized as controlled release matrix. • Microwave irradiated Free radical assisted method was used for the synthesis. • The optimized grade showed swelling sensitivity at pH 7.0 with controlled release properties with release of drugs for 26 h. [ABSTRACT FROM AUTHOR]

Poly(arylene piperidinium) (PAP) anion-exchange membranes (AEMs) are attractive platform materials currently used for anion-exchange membrane fuel cells (AEMFCs) and chain branching modifications on PAP polymer structures have recently drawn much attention for effectively regulating the membrane properties. To better understand the influence and interplay of the polymer chain entanglement and free-volume effect from various branched architectures, herein, lightly end-branched EB-PTP/TPB AEMs, using poly(p -terphenyl dimethylpiperidinium) (PTP) as the polymer backbone and bulky rigid 1,3,5-triphenylbenzene (TPB) as the branching agent, are designed and compared to previously reported random-branched RB-PTP/TPB and linear-chain PTP membranes. Intrinsic viscosity, bulk density and positron annihilation lifetime spectroscopy suggest a lesser extent of chain entanglement, but more evident free-volume elements for end-branched EB-PTP/TPB, particularly for higher branched EB-PTP/TPB-1% containing 1 mol% of TPB branching agent, compared with the random-branched RB-PTP/TPB that exhibits a more predominant chain entanglement effect. EB-PTP/TPB AEMs with increased free volume exhibit faster water sorption kinetics and slightly higher ion conductivity, but the concurrent high water sorption levels are disadvantageous to high-temperature ion transport, alkaline stability and water balance management. Even so, EB-PTP/TPB AEMs still show sufficient mechanical robustness, restricted swelling and higher alkaline stability than linear-chain PTP membranes, aided by the considerable extent of chain entanglement. This work reveals branched architecture–AEM property relationships and provides valuable insights towards branched architecture design. [Display omitted] • Anion-exchange membrane (AEM) structure‒property relationship investigated. • Lightly random-branched versus end-branched polymer architecture. • Differences observed in polymer chain entanglement and free volume effects. • End-branched AEM has improved properties and AEMFC performance than unbranched AEM. [ABSTRACT FROM AUTHOR]

The process of preparing a flocculant using concentrated organic matter has demonstrated effective results in enriching organic matter in municipal wastewater. The basic preparation process involves a combination of hydrothermal treatment and chemical modification. To enhance the enrichment effect of organic matter, the optimal hydrothermal conditions and their influence on the characteristics of liquid products and coarse flocculant were investigated. The results indicated that liquid products obtained at 140 °C for 30 min yielded a high concentration of active groups and exhibited a significantly higher molecular weight, making them suitable as precursors for the coarse flocculant. When the dosage of the coarse flocculant was set at 10 mg/L, the turbidity removal rate of the kaolin suspension reached 93 %. In the treatment of municipal domestic sewage, a COD removal rate of approximately 62 % was achieved at a dosage of 10 mg/L. Within the experimental range, a decrease in hydrothermal time and temperature favored the production of more reactive groups from the dissolved polymeric substances (DPS), thereby enhancing the charge density of the coarse flocculant. The intrinsic viscosity of the coarse flocculant was influenced by both the number of reactive groups and the molecular weight of DPS. Specifically, obtaining a molecular weight distribution of 8–9.5 kDa favored the production of a coarse flocculant with high characteristic viscosities. [Display omitted] • A coarse flocculant preparation method was optimized from the hydrothermal pretreatment. • A high number of reactive groups can increase the charge density of the flocculant. • Molecular weight is 8–9.5 kDa with high characteristic viscosity after modification. • A hydrothermal pretreatment condition of 140 °C for 30 min is recommended. [ABSTRACT FROM AUTHOR]

Valorization of non-wood pulp, such as bamboo bleached kraft pulp into high-purity cellulose acetate (CA)-grade dissolving pulp is crucial but challenging in China. Herein, a series of metal salt-based deep eutectic solvents (MSDESs) involving various ZnCl 2 -urea (U), ZnCl 2 -glycerol (G), and ZnCl 2 -lactic acid (LA) are comparatively investigated for this purpose. Thanks to the bifunctional acid sites of Lewis acid ZnCl 2 and Brønsted acid LA, the ZnCl 2 -LA MSDES has the highest acidity (2.62) and interaction affinity to bamboo fibers, leading to the highest efficiency in simultaneous pulp purification and activation. As a result, the resultant upgraded pulp from ZnCl 2 -LA (DES3-F) features remarkable improvements in purity (from 80.8 % to 93.1 %), intrinsic viscosity (from 897 to 419 mg/L), and reactivity (from 18.1 % to 80.8 %). Moreover, the modified acetate product has a high degree of substitution of 2.84 and a yield of 75.5 %. In short, such a proposed MSDES treatment can offer a promising and alternative approach for the manufacture of high-quality dissolving pulp and its derivatives. [Display omitted] • Metal salt deep eutectic solvent (MSDES) with ZnCl 2 -based Lewis acid is prepared. • ZnCl 2 -lactic acid (LA) with bifunctional acid sites features the highest acidity of 2.62. • ZnCl 2 -LA has simultaneous purification and activation mechanisms for bamboo pulp. • The upgraded acetate-grade bamboo dissolving pulp has a high reactivity of 80.8 %. [ABSTRACT FROM AUTHOR]

Traditional viscosity measurements for carrageenan are laborious, present practical and environmental challenges, and fail to provide structure-property understanding for application and manufacturing development. We hypothesize that integrating Size Exclusion Chromatography (SEC) with Multi-Angle Light Scattering (MALS) and online viscometry, combined with chemometric techniques, can develop a more efficient and environmentally friendly method for determining the apparent viscosity of carrageenan solutions. To test this hypothesis, predictive chemometric models were developed using SEC-MALS data for carrageenan extracted from four different seaweed species. By integrating SEC-MALS with Partial Least Squares (PLS) regression, key molecular parameters such as hydrodynamic radius, intrinsic viscosity, and molecular mass were identified as significant influencers of viscosity. The model for carrageenan from Eucheuma denticulatum yielded the lowest prediction error (RMSEP 8.4), while those for carrageenan extracted from Kappaphycus alvarezii or from several species of the Chondrus genus showed higher errors due to κ-carrageenan sensitivity. For carrageenan extracted from seaweed of the Gigartina genus, incorporating the root mean square radius resulted in a low prediction error of 10. This study concludes that integrating SEC-MALS with PLS regression effectively identifies key molecular parameters influencing carrageenan viscosity, enhancing structure-property understanding and providing a reliable analytical method for optimizing quality control and application in various industries. [Display omitted] [ABSTRACT FROM AUTHOR]

This study investigated the changes in the properties of polyamide 66 (PA66) industrial fibers during UV aging and explored the underlying UV aging mechanisms through structural data analysis across varying length scales. The findings reveal a three-stage progression in the deterioration of mechanical properties due to UV aging. Initially, in the pre-aging stage (t ≤ 1 day), both mechanical properties and microscopic structural parameters remain stable, showing no significant changes. Following this, UV-induced degradation and concurrent recrystallization in the amorphous region result in a decline in mechanical parameters as the aging process continues, albeit with varying magnitudes across the stages. A notable decrease in tenacity and elongation at break is observed in the mid-aging stage (1 day < t ≤ 49 days). While the formation of low-melting-point microcrystals enhances crystallinity and crystalline size, the predominant effect of molecular chain scission due to UV exposure leads to a significant increase in carbonyl group content and a marked decrease in intrinsic viscosity. Furthermore, the formation of microcrystals hinders oxygen diffusion, resulting in the gradual stabilization of intrinsic viscosity and carbonyl content in the late-aging stage (t > 49 days), which significantly slows the deterioration of mechanical properties. These results indicate that UV-induced molecular degradation is the primary driver of changes in break elongation, while the development of new crystalline structures within the fibers contributes to the preservation of mechanical properties. [Display omitted] • Structural evolutions of PA66 industrial fibers during ultraviolet (UV) aging process were investigated. • Revealing the UV aging mechanism of PA66 industrial fibers. • UV-degradation and recrystallization in amorphous regions occur simultaneously under the long duration aging condition. [ABSTRACT FROM AUTHOR]

Novel polyarylates containing phthalazinone moieties (PAR-PH) were synthesized and characterized by co-solvent interfacial polymerization based on 4-(4′-hydroxyphenyl)-2,3-phthalazin-1-one (DHPZ) and isophthaloyl chloride (IPC). Effects of inorganic bases, monomer concentration, phase transfer catalysts and co-solvents on the interfacial polymerization reaction were investigated. When the organic phase solvent was cyclohexane with 3% butanone and 18-crown-6 was the phase transfer catalyst, PAR-PH achieved a maximum intrinsic viscosity (η int ) up to 0.52 dL/g. For some organic phase solvents of alkanes and chlorinated hydrocarbons, the addition of co-solvents increased the η int of the polymer. PAR-PH exhibit excellent thermal resistance due to the introduction of rigid twisted phthalazinone moieties into the polymer main chains, with glass transition temperature (T g ) of 275°C. The 5% thermal weight loss temperature of PAR-PH was 463°C in N2 and residual mass ratios at 800°C of 52.0%, demonstrating excellent thermal stability. [ABSTRACT FROM AUTHOR]

• Below T m of PEU, hydrolysis preferentially occurs at the COO groups of soft-segments. • Above T m of PEU, hydrolysis can occur at the urethane groups of hard-segments. • PEU exhibits a structural failure point when hydrolysis attacks the urethane groups. • A critical molecular weight (M C) is associated with this structural failure point and increases with temperature/humidity. • More structure/property relationships are established for hydrolyzed PEU. • The effect of T m on E a of PEU hydrolysis is investigated. Many structure/property relationships of hydrolyzed poly(ester urethane) (PEU) – a thermoplastic – have been reported. Examples include changes in molecular weight vs. elongation at break and crosslink density vs. mechanical strength. However, the effect of molecular weight (or molar mass) reduction on some physical, thermal, and chemical properties of hydrolyzed PEU have not been reported. Therefore, a large set of hydrolyzed PEU (Estane®5703) samples were obtained from two aging experiments: 1) accelerated aging conducted under various environments (air, nitrogen, moisture) and at 64 °C and below for almost three years, and 2) natural aging conducted under ambient conditions for more than three decades. The hydrolyzed samples were characterized via multi-detection gel permeation chromatography (GPC), thermogravimetric analysis (TGA), modulated differential scanning calorimetry (mDSC), UV–vis spectroscopy, nuclear magnetic resonance (NMR), and Fourier-transform infrared (FTIR) spectroscopy techniques. Hydrolysis of ester linkages in the soft-segments decreases both the molecular weight (M w) and the melting point (T m) of Estane (from ∼55 °C to 39 °C). Aging above this T m , increased mobility of polymer chains and water diffusivity in the PEU matrix alter the PEU degradation pathway from those expected at aging temperatures below this T m and have significant bearing on the critical molecular weight (M C) at which the physical, chemical, thermal, and mechanical properties of Estane change abruptly. While a M C value of 20 kDa is found for PEU hydrolysis at mild temperatures (e.g., as low as 39 °C), the value of M C increases with increasing aging temperatures. To complement the existing structure/property relationships reported in the literature, more correlations are obtained, which include the effect of M w on polydispersity, intrinsic viscosity (Mark-Houwink equation), UV extinction coefficient, and dn/dc (GPC analysis) values. Furthermore, we seek to bolster previously reported aging models for PEU by developing a practical model with which the extent of degradation and material performance can be predicted based on aging under different temperature ranges both above and below the melting point of Estane. [Display omitted] [ABSTRACT FROM AUTHOR]

Copyright of Oilfield Chemistry is the property of Sichuan University, Oilfield Chemistry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cationic polyacrylamide (CPAM) is a commonly used flocculant for water treatment. Factors that affect the flocculation effect and can be controlled manually include the type and dosage of CPAM, wastewater pH, stirring time and settling time, and their reasonable setting is critical to the flocculation effect of CPAM. In this paper, the optimal flocculation conditions of a novel CPAM were studied. First, single-factor tests were conducted to preliminarily explore the optimal range of factors that influence CPAM flocculation, and then response surface methodology (RSM) tests were performed to accurately determine the optimums of the influencing factors. The results showed that the flocculation effect was better when the intrinsic viscosity was larger or the cationic degree of CPAM was higher. The CPAM dosage, wastewater pH and stirring time significantly impacted the flocculation effect, and inflection points were observed. A model that could guide CPAM-8.14-40.2 flocculation was obtained by RSM tests. The model optimization showed that the optimal flocculation conditions of CPAM-8.14-40.2 for treating wastewater prepared with kaolin were as follows: the CPAM dosage, wastewater pH and stirring time were 5.83 mg·L−1, 7.28, and 5.95 min, respectively, and the turbidity of the treated wastewater was reduced to 6.24 NTU. [ABSTRACT FROM AUTHOR]

Ultra-stable fluoropolymer glasses were created using vacuum pyrolysis deposition that show large fictive temperature Tf reductions relative to the glass transition temperature Tg of the rejuvenated material. Tf was also found to be 11.4 K below the dynamic VFT temperature TVFT. Glass films with various thickness (200–1150 nm) were deposited onto different temperature substrates. Glassy films were characterized using rapid-chip calorimetry, Fourier-transform infrared spectroscopy and intrinsic viscosity measurements. Large enthalpy overshoots were observed upon heating and a Tf reduction of 62.6 K relative to the Tg of 348 K was observed. This reduction exceeds values reported for a 20-million-year-old amber and another amorphous fluoropolymer and is below the putative Kauzmann temperature TK for the material as related to TVFT. These results challenge the importance of the Kauzmann paradox in glass-formation and illustrates a powerful method for the exploration of material dynamics deep in the glassy state (Tf < T < Tg). [ABSTRACT FROM AUTHOR]

The melt fluidity of polycarbonate (PC) significantly influences the processing, while the melt viscosity depends on the molecular structure. Specifically, the melt viscosity increases sharply with the increase of polymerization degree. However, the influence mechanism of alkali metal catalysts on the fluidity by affecting the molecular structure remains unclear. Herein, high and low concentrations of NaOH catalysts were used to synthesize PC with different polycondensation degrees. The effect of NaOH catalyst content on the molecular structure and thus melt fluidity of PC were systematically characterized and discussed employing NMR spectroscopy, absolute and relative molecular weight, intrinsic viscosity, melt flow index, and thermal analysis. The results show that a random branched structure of the PC molecular chain caused by excess NaOH improves the melt flowability. However, the residual NaOH promotes the degradation of carbonate bonds during thermal processing, resulting in poor PC stability. Based on the above discussion, empirical fitting equations are proposed to describe the relationship between molecular structure and flow properties, which provides a new way to judge PC performance. [ABSTRACT FROM AUTHOR]

The preparation of biodegradable films using, tamarind seed powder (TSP) and fenugreek seed powder (FSP) has been reported herein. The tamarind seed powder (TSP) was used to prepare pure films as T1, T2 and T3, based on particle size Grade-I, II and III, similarly, FSP films were prepared as F1, F2 and F3, whereas composite films from (TSP and FSP) were prepared with (50:50) ratio based on above grades were as TF1, TF2 and TF3, respectively. The textural properties of the films prepared from pure TSP as T1; pure (FSP) as F1 and composite films of TSP and FSP as TF1 were found to be better than that of other films. The heat capacity (Hc), determined using DSC, was found in the range of 0.089–2.260 kgm2/ks2 for all the films. The microbial analysis performed using the Aerobic colony count and Yeast and mold count methods showed the least microbial count for the film containing FSP due to the anti-microbial properties of fenugreek. The SEM analysis found smoother surfaces with the closeness of pores for T1, F1 and TF1 films. The Water vapor permeability was in the range of 0.49–0.82 mg/Pa.s.m2 × 10–11. The evaluation of the biodegradability of the films was done by soil burial test, and intrinsic viscosity measurements at different time intervals were found better results for T1, F1 and TF1 films. Pure TSP and pure FSP films with Grade I mucilage found better for packaging application. [ABSTRACT FROM AUTHOR]

Poly(butylene sebacate-co-terephthalate) (PBSeT) has generated attention as a promising biopolymer for preparing bioplastics. However, there are limited studies on the synthesis of PBSeT, impeding its commercialization. Herein, with a view to addressing this challenge, biodegradable PBSeT was modified using solid state polymerization (SSP) with various ranges of time and temperature. The SSP used three different temperatures below the melting temperature of PBSeT. The polymerization degree of SSP was investigated using Fourier-transform infrared spectroscopy. The changes in the rheological properties of PBSeT after SSP were investigated using a rheometer and an Ubbelodhe viscometer. Differential scanning calorimetry and X-ray diffraction showed that the crystallinity of PBSeT was higher after SSP. The investigation revealed that after SSP for 40 min at 90 °C, PBSeT exhibited higher intrinsic viscosity (increased from 0.47 to 0.53 dL/g), crystallinity, and complex viscosity than PBSeT polymerized at other temperatures. However, a high SSP processing time resulted in a decrease in these values. In this experiment, SSP was most effectively performed in the temperature range closest to the melting temperature of PBSeT. This indicates that SSP could be a facile and rapid method for improving the crystallinity and thermal stability of synthesized PBSeT. [ABSTRACT FROM AUTHOR]

We examine the impact of confinement on the structure, dynamics, and rheology of spherically confined macromolecular suspensions, with a focus on the role played by entropic forces, by comparing the limits of strong hydrodynamics and no hydrodynamics. We present novel measurements of the osmotic pressure, intrinsic viscosity, and long-time self-diffusivity in spherical confinement and find confinement induces strong structural correlations and restrictions on configurational entropy that drive up osmotic pressure and viscosity and drive down self-diffusion. Even in the absence of hydrodynamics, confinement produces distinct short-time and long-time self-diffusion regimes. This finding revises the previous understanding that short-time self-diffusion is a purely hydrodynamic quantity. The entropic short-time self-diffusion is proportional to an entropic mobility, a direct analog to the hydrodynamic mobility. A caging plateau following the short-time regime is stronger and more durable without hydrodynamics, and entropic drift—a gradient in volume fraction—drives particles out of their cages. The distinct long-time regime emerges when an entropic mobility gradient arising from heterogeneous distribution of particle volume drives particles out of local cages. We conclude that entropic mobility gradients produce a distinct long-time dynamical regime in confinement and that hydrodynamic interactions weaken this effect. From a statistical physics perspective, confinement restricts configurational entropy, driving up confined osmotic pressure, viscosity, and (inverse) long-time dynamics as confinement tightens. We support this claim by rescaling the volume fraction as the distance from confinement-dependent maximum packing, which collapses the data for each rheological measure onto a single curve. [ABSTRACT FROM AUTHOR]

Summary: The effects of the solvent composition of ethanol and acetic acid (50/50 and 70/30 v/v), time (30 and 60 min) and temperature (65 and 95°C) of hydrolysis were conducted on the structural and physicochemical properties of ethyl cellulose (EC). Differential scanning calorimetry (DSC) and capillary viscometer results revealed that EC hydrolysis significantly decreased glass transition temperature (Tg) and intrinsic viscosity. FTIR spectra of hydrolysed EC (H‐EC) revealed a breakdown of many glycosidic bonds. The oleogels were prepared by H‐EC at the concentration of 6 wt%. Results showed that hydrolysis conditions significantly affected oleogel formation and strength. An optimal oleogel structure was achieved with H‐EC at 65°C, 50/50 solvent ratio (H‐EC65/50). The rheological analysis of H‐EC65/50 oleogel showed higher strength and a lower melting temperature range than EC oleogel. Microscopic observations confirmed that the H‐EC65/50 forms a new structure with many small cavities, probably the main reason for the firmer gel. The prepared formulation could have potential to prepare reduced fat formulations with the suitable melting point and texture. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology / Zhongguo Shipin Xuebao is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The polymerization process, as the starting point of polyester fibre production, directly affects the fibre properties. However, the polymerization process has complex reaction mechanisms and involves many variables, making online modelling more challenging. In this paper, we introduce the Copula function into the modelling of the polymerization process. First, a feature selection method based on kernel principal component analysis (KPCA)‐Copula is proposed, and then, the Copula function to obtain the nonlinear characteristics among the variables is used. On this basis, an online prediction model of intrinsic viscosity based on just‐in‐time learning (JITL) was established, that is, empirical Copula‐JITL. In order to improve the computational efficiency of the empirical Copula‐JITL, the t‐Copula function is introduced. Furthermore, by combining the t‐Copula function with the empirical Copula function, we get a JITL model based on the hybrid Copula function, that is, hybrid Copula‐JITL. Finally, actual polymerization process data collected from fibre production are provided to demonstrate the effectiveness of the proposed algorithms. [ABSTRACT FROM AUTHOR]

The objective of this study was to explore the structural changes and oxidation resistance of ultrasonic degradation products of sugar beet pectin (SBP). The changes in the structures and antioxidant activity between SBP and its degradation products were compared. As the ultrasonic treatment time increased, the content of α-D-1,4-galacturonic acid (GalA) also increased, to 68.28%. In addition, the neutral sugar (NS) content, esterification degree (DE), particle size, intrinsic viscosity and viscosity-average molecular weight (MV) of the modified SBP decreased. Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) were used to study the degradation of the SBP structure after ultrasonication. After ultrasonic treatment, the DPPH and ABTS free radical scavenging activities of the modified SBP reached 67.84% and 54.67% at the concentration of 4 mg/mL, respectively, and the thermal stability of modified SBP was also improved. All of the results indicate that the ultrasonic technology is an environmentally friendly, simple, and effective strategy to improve the antioxidant capacity of SBP. [ABSTRACT FROM AUTHOR]

This work evaluates the application effect and mechanism of superplasticizers (SPs) in alkali-activated materials (AAM). Naphthalene superplasticizer (NS), aliphatic superplasticizer (AS) and polycarboxylate superplasticizer (PS) were selected, and three aluminosilicate precursors and two alkali activators were used to prepare AAM. The results showed that all three SPs cannot effectively improve the fluidity of AAM paste, but have certain plasticizing effect in AAM mortar. Both the molecular structure and absorption property of the three SPs changed in AAM. The activator NaOH had more serious damage to the molecular structure of SPs, while the competitive adsorption of Na2SiO3 to SPs was more intense. The intrinsic viscosity and infrared spectrum characteristic peak of AS were relatively stable, followed by NS, while the PS molecule was the most unstable in the alkaline environment. For precursors, metakaolin had the highest surface adsorption energy, resulting in its winding with the incomplete SPs molecule damaged by activator and a decrease in paste fluidity. For fly ash with a smooth surface and low calcium content, its absorption capacity to SPs was the worst, having the smallest adsorption layer thickness of SPs and |ζ| potential. Although the slag could form effective absorption with the anion of SPs, there was significant competition for calcium ions between the SPs and activators, causing the detachment of SPs from the slag surface. [ABSTRACT FROM AUTHOR]

The peculiarities of viscosity data treatment for two series of polymer systems exhibiting associative properties: brush-like amphiphilic copolymers—charged alkylated N-methyl-N-vinylacetamide and N-methyl-N-vinylamine copolymer (MVAA-co-MVACnH2n+1) and charged chains of sodium polystyrene-4-sulfonate (PSSNa) in large-scale molecular masses (MM) and in extreme-scale of the ionic strength of solutions were considered in this study. The interest in amphiphilic macromolecular systems is explained by the fact that they are considered as micellar-forming structures in aqueous solutions, and these structures are able to carry hydrophobic biologically active compounds. In the case of appearing the hydrophobic interactions, attention was paid to discussing convenient ways to extract the correct value of intrinsic viscosity η from the combined analysis of Kraemer and Huggins plots, which were considered as twin plots. Systems and situations were demonstrated where intrachain hydrophobic interactions occurred. The obtained data were discussed in terms of ln η r vs. c η plots as well as in terms of normalized scaling relationships where η r was the relative viscosity of the polymer solution. The first plot allowed for the detection and calibration of hydrophobic interactions in polymer chains, while the second plot allowed for the monitoring of the change in the size of charged chains depending on the ionic strength of solutions. [ABSTRACT FROM AUTHOR]

The natural glycopeptide antibiotic teicoplanin is used for the treatment of serious Gram-positive related bacterial infections and can be administered intravenously, intramuscularly, topically (ocular infections), or orally. It has also been considered for targeting viral infection by SARS-CoV-2. The hydrodynamic properties of teicoplanin A2 (M1 = 1880 g/mol) were examined in phosphate chloride buffer (pH 6.8, I = 0.10 M) using sedimentation velocity and sedimentation equilibrium in the analytical ultracentrifuge together with capillary (rolling ball) viscometry. In the concentration range, 0–10 mg/mL teicoplanin A2 was found to self-associate plateauing > 1 mg/mL to give a molar mass of (35,400 ± 1000) g/mol corresponding to ~ (19 ± 1) mers, with a sedimentation coefficient s20, w = ~ 4.65 S. The intrinsic viscosity [ η ] was found to be (3.2 ± 0.1) mL/g: both this, the value for s20,w and the hydrodynamic radius from dynamic light scattering are consistent with a globular macromolecular assembly, with a swelling ratio through dynamic hydration processes of ~ 2. [ABSTRACT FROM AUTHOR]

In this work, we report our results on the hydrodynamic behavior of poly(2-methyl-2-oxazoline) (PMeOx). PMeOx is gaining significant attention for use as hydrophilic polymer in pharmaceutical carriers as an alternative for the commonly used poly(ethylene glycol) (PEG), for which antibodies are found in a significant fraction of the human population. The main focus of the current study is to determine the hydrodynamic characteristics of PMeOx under physiological conditions, which serves as basis for better understanding of the use of PMeOx in pharmaceutical applications. This goal was achieved by studying PMeOx solutions in phosphate-buffered saline (PBS) as a solvent at 37 °C. This study was performed based on two series of PMeOx samples; one series is synthesized by conventional living cationic ring-opening polymerization, which is limited by the maximum chain length that can be achieved, and a second series is obtained by an alternative synthesis strategy based on acetylation of well-defined linear poly(ethylene imine) (PEI) prepared by controlled side-chain hydrolysis of a defined high molar mass of poly(2-ethyl-2-oxazoline). The combination of these two series of PMeOx allowed the determination of the Kuhn–Mark–Houwink–Sakurada equations in a broad molar mass range. For intrinsic viscosity, sedimentation and diffusion coefficients, the following expressions were obtained: η = 0.015 M 0.77 , s 0 = 0.019 M 0.42 and D 0 = 2600 M − 0.58 , respectively. As a result, it can be concluded that the phosphate-buffered saline buffer at 37 °C represents a thermodynamically good solvent for PMeOx, based on the scaling indices of the equations. The conformational parameters for PMeOx chains were also determined, revealing an equilibrium rigidity or Kuhn segment length, (A) of 1.7 nm and a polymer chain diameter (d) of 0.4 nm. The obtained value for the equilibrium rigidity is very similar to the reported values for other hydrophilic polymers, such as PEG, poly(vinylpyrrolidone) and poly(2-ethyl-2-oxazoline), making PMeOx a relevant alternative to PEG. [ABSTRACT FROM AUTHOR]

Utilizing the copolymerization modification of dimethyl diallyl ammonium chloride (DMDAAC), the high positive charge density of the copolymer could be maintained, thereby facilitating the deficiency of its monomer in the application. In this paper, poly (DMDAAC-co-DAMBAC) (9:1) was synthesized with an aqueous polymerization method using DMDAAC and methyl benzyl diallyl ammonium chloride (DAMBAC) as monomers and 2,2'-azobis [2-methylpropionamidine] dihydrochloride (V50) as an initiator. Targeted to the product's weight-average relative molecular mass (Mw), the response surface methodology (RSM) was used to optimize the preparation process. The optimal process conditions were obtained as follows: w (M) = 80.0%, m (V50):m (M) = 0.00700%, m (Na4EDTA):m (M) = 0.00350%, T1 = 50.0 °C, T2 = 60.0 °C, and T3 = 72.5 °C. The intrinsic viscosity ([η]) of the product was 1.780 dL/g, and the corresponding double bond conversion (Conv.) was 90.25 %. Poly (DMDAAC-co-DAMBAC) (9:1) revealed a highest Mw of 5.637 × 105, together with the polydispersity index d (Mw/Mn) as 1.464. For the demulsification performance of simulated crude oil O/W emulsions, the demulsification rate of poly (DMDAAC-co-DAMBAC) (9:1) could reach 97.73%. Our study has illustrated that the copolymerization of DMDAAC and a small amount of DAMBAC with poor reactivity could significantly improve the relative molecular weight of the polymer, enhance its lipophilicity, and thus the application scope of the polymer. [ABSTRACT FROM AUTHOR]

Besides delivering drug to the body, a drug delivery system aims to improve patient compliance, patient acceptance. The dosage formsavailable for the delivery of topical agents include ointment, paste, CREAM, moisturizing cream and powder. However, cream is more preferabledue to their properties. Present research work is attempted to develop gel by using rice bran wax. Rice bran wax is the vegetable waxextracted from rice bran oil. The oil generally contains 2-6% wax. However it is assumed that on an average it contains 3% wax. Physicochemical tests such as globule size, evaluation of the intrinsic viscosity and homogeneity of cream products, have been traditionallyused to provide reasonable evidence of consistent product performance. However, for the purposes of these studies, the final cream productswere characterized for their clarity, pH, viscosity, spread ability, skin irritation test and in vitro diffusion studies using standard procedure. All the results match with official specifications. [ABSTRACT FROM AUTHOR]

Polyimide (PI) dielectric nanocomposites containing functional nanofillers based on layered structure (single‐layer: BT@Al2O3@PI, double‐layer: PI/BT@Al2O3@PI, three‐layer: PI/BT@Al2O3@PI/PI) were designed and prepared by using PI as matrix, barium titanate (BT)@alumina (Al2O3) as nanofillers through in‐situ polymerization compounding technology. FTIR tests indicated that PI and PI dielectric nanocomposites have been synthesized successfully. The molecular mass of BaTiO3@Al2O3@PAA oligomer was higher than that of pure PAA when BT and Al2O3 nanofillers were incorporated simultaneously, as verified by GPC and intrinsic viscosity tests. XRD analysis showed that the addition of nanofillers destroyed the order of PI molecular structure and reduced the arrangement density of PI molecular chains. Both FESEM and HRTEM observations showed that the nanofillers were homogeneously dispersed in the PI matrix, contributing to the property improvements of PI dielectric nanocomposites. TGA results indicated that adding nanofillers improved the thermal stability and heat resistance of PI dielectric nanocomposites. The dielectric constant of PI/BT@Al2O3@PI double‐layer nanocomposites was between the single‐layer nanocomposites and pure PI. Due to the effective medium theory, the dielectric constant of three‐layer PI/BT@Al2O3@PI/PI nanocomposites containing 5 wt% BT@Al2O3 reached 5.43. This work can be expected to provide an effective strategy to fabricate PI dielectric nanocomposite films for energy storage applications. [ABSTRACT FROM AUTHOR]

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An amphiphilic cellulose derivative the sodium salt of cellulose sulfoacetate was studied in a wide range of molecular masses by the methods of molecular hydrodynamics. Molecular masses were determined from sedimentation-diffusion analysis. The cross and general scaling relationships were established in the studied range of molecular masses for intrinsic viscosity and coefficients of velocity sedimentation and translational diffusion, and molecular masses. The conformational characteristics of the chains, such as the persistence length, hydrodynamic diameter were established using the Multi-HYDFIT suite applied to the entire set of experimental data. The features of using the Multi-HYDFIT suite for calculation of molecular mass per unit length of linear chains are discussed. The results obtained for this cellulose sulfoacetate series have been compared with literature data for other water-soluble cellulose derivatives using normalized scaling concept of intrinsic viscosity data. It has been shown that water-soluble cellulose derivatives form a community, which is characterized by virtually identical equilibrium sizes of rigid chains in aqueous solutions. [ABSTRACT FROM AUTHOR]

Streptococcus thermophilus is a species frequently used in the manufacture of fermented milk. Apart from acid production, some strains additionally synthesize exopolysaccharides (EPS) which contribute to texture improvement and syneresis reduction, both being attributable to the EPS's high water binding capacity. There are two different types of EPS that may be produced, namely free exopolysaccharides (fEPS) which are secreted into the medium, and capsular EPS (cEPS) which remain attached to the bacterial cell wall. This study aims to analyze their individual contribution to techno-functional properties of fermented milk by determining the moisture sorption behavior of isolated fEPS and cell-attached cEPS from two S. thermophilus strains separately: ST-1G, a producer of non-ropy fEPS and cEPS, and ST-2E, a producer of ropy fEPS and cEPS. Differences in moisture load and sorption kinetics, determined for the first time for microbial EPS, were related to structural and macromolecular properties. The observed data are discussed by using previously published data on the physical properties of stirred fermented milk produced with these two strains. ST-1G EPS showed a higher cEPS fraction, a higher moisture load and slower moisture desorption than EPS produced by ST-2E, thus contributing to lower syneresis in fermented milk. For ST-2E, higher gel viscosity was related to a higher intrinsic viscosity and molecular mass of the ropy fEPS. Both strains produced complex EPS or EPS mixtures with clearly different molecular structures. [ABSTRACT FROM AUTHOR]

In recent years, there has been a trend toward replacing petrochemical raw materials with so-called "bio" plastics, i.e. plastics from renewable sources. Herein, the susceptibility of degradation in the compost heap of three types of packaging polyesters, by means of PET and biobased PEF and PLA, with other thermoplastic polyesters with more methylene groups (three and six) bio—(PTF and PHF, respectively) and petrochemically-based (PTT and PHT, respectively) has been studied. Two series of polymer materials based on ethylene, propylene, and hexamethylene glycols and two diesters (dimethyl terephthalate and dimethyl 2,5-furandicarboxylate) were thus obtained and compared with "double green" PLA. Moreover, the assessment of the influence of the subsequent processing cycle (injection moulding) on the utilitarian properties of these materials, constitutes the analogy to the subsequent recycling cycle. The susceptibility to degradation was assessed in the context of changes in the structure (analyzed by FTIR and DSC), intrinsic viscosity, and mechanical performance. In addition, chromatographic analysis of the solutions of the analyzed samples in methanol was carried out in order to determine whether and what low-molecular compounds were released from the analyzed polyesters. It has been shown that furan-based polyesters have great potential to replace materials based on dimethyl terephthalate-based polyesters. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Donghua University (Natural Science Edition) is the property of Journal of Donghua University (Natural Science) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, chitosan (CS), acrylamide (AM) and itaconic acid (IA) were selected as raw monomers to prepare a novel flocculant CS-g-P(AM-IA) for heavy metals’ removal. CS-g-P(AM-IA) are rich with carboxylic acid ionic groups through ultrasonic-free radical initiated polymerization. The CS-g-P(AM-IA) has both chelation coordination and flocculation effect, which is used for removing heavy metal Pb2+ efficiently. The effects of one-factor experimental preparation conditions such as initiator concentration, total monomer concentration, total mono-chitosan mass ratio and ultrasound time on the intrinsic viscosity of CS-g-P(AM-IA) were investigated. Thus, the optimization of ultrasonically initiated CS graft polymerization mechanisms and preparation conditions will be further understood and explored. The results of Fourier-transform infrared spectroscopy, thermogravimetry/differential scanning calorimetry (TG/DSC) and scanning electron microscopy (SEM) indicated that CS was successfully grafted by AM and IA. In addition, TG/DSC and SEM analyses showed that CS-g-P(AM-IA) had better thermal stability and rougher surface topography, respectively. The chelating–flocculation experimental results showed that the removal rate of Pb2+ reached 84.5% and 64.3% by CS-g-P(AM-IA) and CS at pH = 5.0, flocculation time of 25 min, flocculant dosage of 3.0 mg/L, respectively. The Pb2+ removal effect by CS-g-P(AM-IA) was obviously superior than that of CS. The ionic strength and coexisting positive ions have an adverse effect on the adsorption performance for the flocculants, and the effect of Ca2+ was obvious. Pb2+ ions were mainly immobilized by CS-g-P(AM-IA) through chelation and flocculation by its IA carboxyl groups. And then it was generated large and dense heavy metal flocs (d50 = 275.9 μm, Df = 1.91) by adsorption bridge, net trapping and sweeping to enhance the separation and removal performance of Pb2+ ions. [ABSTRACT FROM AUTHOR]

In this research, a biodegradable starch/Fe3O4/TiO2 bio-nanocomposites (SFT) were produced using different nano Fe3O4/TiO2 (FT) (3, 5, and 10 (wt% dry based)) contents. Mechanical properties, visual properties, moisture-sensitive parameters, magnetic properties, and physical properties of the film specimens were investigated. Photodegradability of film specimens was also evaluated under UV-A irradiation. The FT content increased the hydrophobicity of the film specimens. Tensile strength (TS) of SFT films was increased by increasing FT up to 3%. Elongation at break (EB) and tensile energy to break (TEB) were decreased by adding FT content up to 3% simultaneously. The film specimens' water vapor permeability (WVP) was decreased with increasing FT content. The intrinsic viscosity of SFT was decreased by increasing FT content. It confirms the enhancement of photodegradability of the specimens by increasing FT content. It seems the compatibility of FT with biopolymer has had great effects on these properties. Use of FT-based nanocomposites is an appropriate approach to developing magnetic-recyclable and photodegradable packaging materials. [ABSTRACT FROM AUTHOR]

The processes to obtain value-added products from brewers' spent grain, a contaminant industrial waste, require alkaline non-ecofriendly pre-treatments. The arabinoxylans from brewers' spent grain were extracted by nixtamalization evaluating the extraction procedure, antioxidant capacity and molecular characteristics. The best arabinoxylans yields were those extracted with CaO at 100 °C and 25 °C (6.43% and 3.37%, respectively). The antioxidant capacity by 2,2-diphenyl-1-picrylhydrazyl assay of the arabinoxylans after thermal treatment and additional arabinoxylans after thermal treatment proteolysis were 434 and 118 mg TE/g, while by 2,20′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt assay the value was similar (380 μmol TE/g). The intrinsic viscosities and viscosimetric molecular weights were 69 mL/g and 13 kDa for arabinoxylans after thermal treatment, and 15 mL/g and 1.6 kDa for arabinoxylans after thermal treatment proteolysis, respectively. The protein and lignin contents were 3.1% and 6.4% for arabinoxylans after thermal treatment and, 0.9% and 4.6% for arabinoxylans after thermal treatment proteolysis, while their arabinose: xylose ratios were 0.39 and 0.36, with ferulic acid contents of 0.63 and 0.14 mg/g, respectively. Both products of arabinoxylans were molecularly identical by Fourier transform infra-red. Although the purity of the extracted arabinoxylans was improved with proteolysis, their intrinsic viscosity and viscosimetric molecular weight were affected. The extraction of arabinoxylans from brewers' spent grain by CaO nixtamalization alone or after additional proteolysis was successful to obtain purity and good antioxidant capacity. [ABSTRACT FROM AUTHOR]

Aspects of implementing the homophasic free-radical synthesis in DMSO of a fiber-forming tercopolymer (FTP) based on acrylonitrile, methacrylate, and 2-acrylamide-2-methylpropanesulfonic acid with a given intrinsic viscosity are considered. The macrokinetic process parameters, yield, and intrinsic viscosity of the FTP as a function of the initiator content in the reaction solution are established. General and distinguishing features of the FTP syntheses in DMSO and DMF are discussed. [ABSTRACT FROM AUTHOR]