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The absence of chain ends makes ring polymers distinctly different from their linear analogues. The intrinsic viscosity, complex viscosity and the dielectric relaxation of ring polymers are investigated within the tenets of the optimized Rouse–Zimm theory. The distance dependent excluded volume interactions (EVIs) are obtained from Flory's mean field theory. The hydrodynamic interactions (HIs) between the pairs of monomers are estimated using the preaveraged Oseen tensor. The intrinsic viscosity of linear and ring polymers both with and without EVI are compared as a function of ring size. A monotonically increasing trend of the intrinsic viscosity is observed in both cases. The intrinsic viscosity of both linear and ring polymers both with and without EVI show a very good agreement with the experimental results of polystyrene over a wide range of molecular weights in both good and theta solvents, respectively. The fractal dimensions of the ring polymers with EVI lie between that of a random walk and a self-avoiding walk model of linear polymers in three dimensions. The ring size increases with EVI and the effect of EVI is stronger on larger rings than that on smaller rings. The dielectric relaxation follow a connectivity independent universal scaling behavior at low and high frequency regions. The imaginary part of the complex dielectric susceptibility displays a local maxima in the intermediate frequency region, which reveals a structure dependent behavior of the rings. The theoretically calculated dielectric loss of ring polymers with HI matches well with those obtained from experiments. [ABSTRACT FROM AUTHOR]

The current study utilized a green synthesis where microwave-assisted free radical technique was applied for economical synthesis of a novel biocompatible polymethyl methacrylate grafted moringa gum amphiphilic graft copolymer, focusing on optimization based on percentage yield, percentage grafting, and intrinsic viscosity was performed, and analytical characterizations confirmed successful grafting. The copolymer demonstrated surfactant-like properties, as evidenced by the determined critical micelle concentration (CMC). Evaluation of its impact on poorly water-soluble drugs, simvastatin, and metronidazole benzoate, revealed efficient release within 60 min. Safety assessments, including In vitro assessments like hemocompatibility, bactericidal activity, fish toxicity, and in vivo evaluations such as oral toxicity, and wound repair studies and cell toxicity studies indicated the safety profile of prepared graft copolymer and explored its potential as a biopolymer for pharmaceutical delivery and tissue regrowth platform. [ABSTRACT FROM AUTHOR]

The effects of concentrated solar radiation on the thermal, chemical, and mechanical properties of post-consumer poly(ethylene terephthalate) (PET) films are studied in the present research work. The films were exposed to solar radiation using a compound parabolic concentrator (CPC), and the results are compared with those obtained from exposing PET films to conditions established in an accelerated weathering chamber (QUV). The CPC and QUV were evaluated on specimens measuring 2 × 13 × 0.5 cm3. Exposure in the CPC was carried out over one year during the periods of February–April, May–July, and October–December. Additionally, in the QUV, the equivalence in hours of exposure to that used in the CPC was sought. The results obtained by differential scanning calorimetry (DSC) indicate a significant increase in crystallinity in the material exposed within CPC, while specimens in QUV exhibited effects related to physical aging. Information obtained from thermogravimetric analysis (TGA) showed a decrease in thermal stability and maximum degradation temperature of the exposed specimens, with a trend consistent with DSC. Intensity decreased in the infrared spectra of films exposed in the CPC, without absorption bands of photo- or thermodegradation. The intrinsic viscosity of specimens exposed to degradation showed a maximum reduction of 17%, attributed to polymeric chain cleavage due to photodegradation. The dynamic mechanical analysis (DMA) evidenced a deterioration in the elastic response of the material, particularly in the one subjected to solar concentration, which is aligned with the surface cracking observed by scanning electron microscopy. [ABSTRACT FROM AUTHOR]

Dissolving-grade pulps serve as the primary material for producing regenerated cellulose fibers, and their utilization is steadily increasing. Despite extensive research efforts, it remains necessary to deepen our understanding of the inherent factors that impact pulp reactivity apart from the well-known degree of polymerization. The Fock reactivity test is commonly used to quantify the reactivity of cellulose pulp by measuring the percentage of cellulose that reacts with carbon disulfide. Dissolving pulps typically require a reactivity of over 90%. Hemicellulose content, intrinsic viscosity, cell wall porosity, crystallinity, and accessible area of four different pulps were characterized and distinct treatments were employed to try to separate the effect of different pulp properties and assess their effect on Fock reactivity. Hemicelluloses removal by xylanase and cold caustic treatments (86% removal) increased the Fock reactivity by 30%, from 55.7% to 71.3%. Assuming the hemicelluloses are fully accessible by the CS2, cellulose reactivity increased from 35.6% to 69.5%,but at the expense of an intrinsic viscosity decrease from 990 cm3/g to 689 cm3/g. This unexpected intrinsic viscosity decrease can be due to the cellulose de-shielding effect provoked by hemicellulose removal and some cellulose degradation during cold caustic extraction. Vibrational impact ball-milling applied on a pulp with 5% hemicellulose content notably boosted Fock reactivity by 56%, from 54% to 84.5%, but two pulp properties, intrinsic viscosity, and crystallinity, decreased concurrently due to the high-energy treatment. This phenomenon complicates identifying a direct correlation between heightened reactivity and a single parameter. To address this, endoglucanase treatment was used to separate intrinsic viscosity from crystallinity, clarifying their contributions to changes in Fock reactivity. Unfortunately, the effect of a given physical or bio/chemical pulp treatment affects more than one pulp property, always including the cellulose degree of polymerization, which has made it difficult to isolate the pulp properties that affect Fock reactivity. Several processes have been tested to obtain pulp with dissolving potential. [ABSTRACT FROM AUTHOR]

This work has focused on oxygen’s role in the delignification process within the context of pulp production. We have investigated the role of oxygen in a complex set of chemical reactions taking place during this process, including both oxidative and non-oxidative reactions. This study explores the impact of pH changes during the oxygen delignification process and the characteristics of the resulting pulps. Additionally, this research examines the effect of oxygen, by comparing conventional oxygen delignification with trials using air and nitrogen. Industrial softwood kraft pulps with a kappa number of 35 were subjected to delignification for 20–120 min under alkaline conditions. The resulting pulps were assessed for kappa number, intrinsic viscosity, fiber charge, and ISO brightness. An important observation from this research is the reduction in lignin molecular weight upon exposure to oxygen and air, suggesting depolymerization reactions facilitated by oxygen species, whereas nitrogen exposure results in less pronounced changes. This finding underscores the impact of oxygen in altering lignin structure, thus informing the selectivity and effectiveness of the delignification process. [ABSTRACT FROM AUTHOR]

For this research, three hydrophobically modified polyacrylamides, HPAAB, HPAAF, and HPAAS, with multiple hydrophobic monomers were designed, synthesized, and used as thickeners in aqueous ink for digital ink-jet printing. The structures were characterized by Fourier transform infrared (FTIR) analysis and nuclear magnetic resonance (NMR) spectroscopy. The viscosity–average molecular weight was determined by intrinsic viscosity determination and was adjusted according to hydrophobic content. The critical association concentration (CAC) of polymers was measured simultaneously using the apparent viscosity method and the fluorescence spectrum. The formation of a network structure and the mechanism of hydrophobic association are visualized dynamically with a scanning electron microscope (SEM) at different concentrations. Under the same conditions, HPAAB exhibited excellent thickening ability across different pH levels, temperatures, and shear rates, which is caused by the longer hydrophobic side chain and the stronger hydrophobic effect of the behenyl polyoxyethylene ether methacrylate (BEM) group. Furthermore, an aqueous ink using HPAAB as a thickener displays significant printability and stability, functioning much better than a corresponding aqueous ink that uses a commercial thickener. This is the first example of a hydrophobic associating polyacrylamide, incorporating both hydrophilic and hydrophobic units within a single hydrophobic chain, thereby serving as an efficient thickener for aqueous ink. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) is widely used in bottle production due to its cost-effectiveness and low environmental impact. The first part of this article describes the research and statistical analysis methodology of the influence of the virgin PET (vPET) and recycled PET (rPET) content in the vPET-rPET blend, as well as the preform heating/cooling conditions in the stretch blow molding (SBM) process on the microscopic bottle properties. Microscopic properties such as crystallinity, density, viscosity, relaxation degree of the amorphous phase, and microcavitation in PET were examined. This study reveals that microcavity and solid-state post-condensation effects occur during PET deformation in the SBM process. The increase in free volume, indicating microcavitation, was confirmed by measuring positron annihilation lifetime spectroscopy (PALS). PALS and density of the amorphous phase studies prove a reduction in the dimensions of the free volumes, with a simultaneous significant increase in their number and ellipsoidization. It can be associated with crystallite rotation in a temperature-dependent non-crystalline matrix. The occurrence of solid-state post-condensation effects was confirmed by measuring the intrinsic viscosity. The conclusions resulting from the analysis of the microstructure affecting the mechanical strength of the material were validated by pressure resistance tests of the bottles. [ABSTRACT FROM AUTHOR]

Gellan gum (GG) emerges as a promising candidate for developing polymeric carriers with extended retention on the ocular surface, aiming to enhance the efficacy of topical ocular drug delivery systems. This study undertakes the purification of commercial GG through fractional dissolution and ultrasonic treatment, producing fractions characterized by 1H, 13C NMR, FTIR spectroscopy and thermogravimetric analysis. The intrinsic viscosity of GG samples was measured in a 0.025 M tetramethylammonium chloride solution and their molecular weights were calculated via the Mark‐Kuhn‐Houwink equation. Methodological choices regarding synthetic procedures, solvents and reagents were guided by considerations of biocompatibility, aligning with the end goal of drug delivery applications. The study further explores the mucoadhesive potential of GG fractions with varying molecular weights for ocular drug delivery, utilizing an in vitro flow‐through technique with fluorescent detection on freshly excised bovine corneal mucosa surfaces. The findings under‐score the viability of GG formulations in enhancing ocular drug retention and pave the way for future applications in topical ocular therapeutics. [ABSTRACT FROM AUTHOR]

A theoretical approach is presented to quantify the effect of ionic strength on the swelling and shrinkage of the hydrodynamic coil size of a generic biopolymer. This was conducted in view of extraction methods that often utilize acids and alkali combinations and, therefore, invariably impact the levels of salt found in commercially available biopolymers. This approach is supplemented by intrinsic viscosity measurements for the purpose of validation across a variety of biopolymer architectures, type of functionalization, as well as the quoted molar mass. By accurately capturing the magnitude of change in the coil size, it is discussed how a biopolymer coil size is far more sensitive to changes in the ionic strength than it is to the molar mass (or contour length) itself. In turn, it is highlighted why the current characterization strategies that make use of weight-averaged molar mass are prone to errors and cannot be used to establish structure—property relationships for biopolymers. As an alternative, the scope of developing an accurate understanding of coil sizes due to changes in the "soft" interactions is proposed, and it is recommended to use the coil size itself to highlight the underlying structure—property relationships. [ABSTRACT FROM AUTHOR]

The influence of pre-treating Kappa number of 18.0 industrial birch kraft pulp with peracetic acid (Paa) before oxygen delignification (OD) was studied relative to the pulps' level of delignification, yield, brightness, intrinsic viscosity (IV), FS-number, tear index (TI), and the consumption of chlorine dioxide (ClO2) in its subsequent Elemental Chlorine Free (ECF) bleaching. The study showed that such pretreatment is a way to extend the delignification of such pulp quite selectively in OD based on values of IV, FS-number, and TI, and to reduce significantly the consumption of ClO2 required to bleach this pulp to a brightness of 87%. This reduction depended on the amount of Paa used for pulp pretreatment. For example, when 0.33% and 0.66% as active oxygen (A.O.) of Paa were used, ClO2 consumption to bleach the pulp to 87% was lowered by 15.4% and 42.3%, respectively. As high as a 61.5% reduction in ClO2 consumption in its bleaching could be obtained using 0.66% as A.O. on pulp and change of time of OD. This result allows for a significant decrease in the chlorine passing to the filtrates from washing the pulp after the D0 and E stages to the pulp mill wastewater treatment plant. [ABSTRACT FROM AUTHOR]

Poly(ethylene glycol 1,4-cyclohexanedimethylene isosorbide terephthalate) (PEICT) copolymers synthesized from isosorbide (ISB), 1,4-cyclohexanedimethanol (CHDM), ethylene glycol (EG) and terephthalic acid (PTA) via polycondensation are a class of heat-resistant bio-based polyesters. The content of biomass-sourced ISB has an important influence on the various properties of the terpolymers but lacks detailed study. Herein, we synthesized a series of amorphous terpolyesters with different contents of ISB by melt polycondensation of ISB, CHDM, EG and PTA in a 30 L reactor, and investigated the effect of ISB content on the thermal, mechanical, optical and rheological properties. As the content of ISB increasing, the complex viscosities of terpolyesters were increased and the intrinsic viscosities were decreased. The tensile strength was increased from 45.1 MPa for poly(ethylene glycol 1,4-cyclohexanedimethylene terephthalate) (PCTG)to 48.1 MPa for PEI13.2CTandthe Tg was increased from 83.5 °C for PCTG (ISB 0 mol%) to 98.8 °C for PEI13.2CT (ISB 13.2 mol%). All the values of Td,5%, and Td,max of the terpolyesters were higher than 395 °C and 425 °C. [ABSTRACT FROM AUTHOR]

The use of the consistency index, as determined from fitting rheological data to the Herschel–Bulkley model, is described such that it may yield systematic trends that allow a very convenient description of the dissipative flow properties of linear and branched (bio)polymers in general, both in molecular and weakly associated supramolecular solutions. The effects of charge-mediated interactions by the systematic variation of the ionic strength and hydrogen bonding by a systematic variation in pH, using levels that are frequently encountered in systems used in practice, is investigated. These effects are then captured using the associated changes in the intrinsic viscosity to highlight the above-mentioned trends, while it also acts as an internal standard to describe the data in a concise form. The trends are successfully captured up to 100 times the polymer coil overlap and 100,000 times the solvent viscosity (or consistency index). These results therefore enable the rapid characterization of biopolymer systems of which the morphology remains unknown and may continue to remain unknown due to the wide-ranging monomer diversity and a lack of regularity in the structure, while the macromolecular coil size may be determined readily. [ABSTRACT FROM AUTHOR]

Ecklonia maxima is an endemic South African seaweed with numerous commercially valuable compounds, including sodium alginate. This polysaccharide contains 1,4-linked β-d-mannuronic (M) and α-l-guluronic acid (G) residues, and has enormous health and food applications and benefits for biomedicine. In this study, acid extraction of sodium alginate from Ecklonia maxima was performed, and its chemical and physical properties were compared with commercial sodium alginate. A yield of 58.7 % (w/w of dry alga) sodium alginate was recovered from the seaweed. As expected, Fourier-transform infrared spectroscopy and nuclear magnetic resonance spectroscopic analyses of sodium alginate revealed the presence of M and G residues in the polysaccharide. Circular dichroism (CD) spectroscopy revealed an M/G ratio of 1.86 from the extracted sodium alginate. The viscosity average molecular weight of sodium alginate was 429 kDa using the Mark–Houwink–Sakurada equation. Three-dimensional conformational analysis by Congo red and CD spectroscopy suggested that sodium alginate exhibits a triple-helix conformation in solution. Furthermore, X-ray powder diffraction analysis confirmed that the alginate has an amorphous structure. Sodium alginate extracted from E. maxima found on the coasts of Southern Africa exhibits a high mannuronic content and high viscosity, potentially beneficial for drug delivery and biomedical applications. [ABSTRACT FROM AUTHOR]

Introduction: Dry eye disease (DED) is one of the most prevalent eye conditions worldwide, with artificial tears serving as a primary treatment option. Despite their wide availability on the European market, there is a lack of established classifications based on their physicochemical properties. The aim of our study was therefore (i) to develop an analytical method that measures the concentration and the molecular weight (MW) of the hyaluronic acid (HA) in commercialized products, and (ii) to propose an overview based on their various physicochemical parameters. Methods: The intrinsic viscosity and MW of the HA, as well as osmolarity, pH, rheological profile, and viscosity, were measured or determined. A specific method was developed to measure the average intrinsic viscosity and HA content using a liquid size-exclusion chromatography system. The MW was determined using the Mark–Houwink equation. Results: Thirty-seven products commercialized in Europe were analyzed, with 21 of them containing HA. The HA MW was lowest (300 kDa) for Thealose®, Thealoz Duo® Gel, and Hyabak®, and highest (1300 kDa) for Vismed® Multi, Vismed® Gel, and Neovis® Gel. The pH values varied between 5.94 for Treovis® and 8.06 for Systane® Ultra. Osmolarity ranged between 148 mOsm/L and 325 mOsm/L for Neovis® and Treovis®, respectively. Viscosity was highly variable, ranging from 0.38 mPas·s for Hylolipid® to 337.47 mPas·s for Thealoz® Duo Gel. Finally, rheological profile analysis revealed different shear-thinning behaviors. Conclusion: While the perfect eye drop does not exist, a multitude of options are available to choose from. This study improves our understanding of the major tear substitutes available on the European market based on several physicochemical properties. A better understanding and awareness of these parameters is crucial in order to offer the best treatment for patients with DED. [ABSTRACT FROM AUTHOR]

The hybrid flocculant P(aluminum chloride-co-diallyldimethylammonium chloride) was synthesized in this study. Diallyldimethylammonium chloride monomers were used and ammonium persulfate served as the initiator. The structure of P(aluminum chloride-co-diallyldimethylammonium chloride) was characterized using Fourier-transform infrared spectroscopy, scanning electron microscopy, an electrical conductivity test, and thermogravimetric analysis. Single-factor experiments were conducted to optimize the synthetic conditions of the hybrid flocculant. An optimized product with an intrinsic viscosity of 926.36 mL/g and a flocculation decolorization rate of 99% was obtained under the following reaction conditions: the total monomer concentration was 30%, the initiator concentration was 0.7%, the reaction temperature was 60 °C, and the reaction time was 3 h. The results demonstrated that the PAC-PDMDAAC hybrid flocculant exhibited covalent bonding between its organic–inorganic components and displayed enhanced stability properties due to its high intrinsic viscosity and spatial structure. Moreover, this hybrid flocculant showed superior decolorization performance in disperse-violet-H-FRL-dye wastewater. [ABSTRACT FROM AUTHOR]

Copyright of China Synthetic Fiber Industry is the property of Sinopec Baling Petrochemical Company 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 recycling of PET trays is highly challenging. The aim of this paper was to investigate the issues related to the mechanical recycling process and, the correlation between feedstock composition and the quality of the produced rPET. Four feedstocks with different degrees of impurity were mechanically recycled at a laboratory pilot scale. The optical and thermal properties of the rPET products were examined to determine the quality and to seek relations with the starting level of impurities. The final products of the PET trays' mechanical recycling were found to be affected by the presence of impurities (organics) and multi-material (non-PET) elements in the feedstocks. The rPET products crystallised faster for contaminated feedstocks showed lower molecular mass and higher yellow index values due to thermal degradation. Yellowing is a crucial parameter in assessing the thermal degradation of rPET. Injection moulded samples corresponding to higher contamination levels, reported values of Yellow Index equal to 179 and 177 compared to 15 of mono-PET sample. The intrinsic viscosity decreased from 0.60 dL/g to just above 0.30 dL/g, and losses were more significant for soiled or multi-material feedstocks. A method of improving the final quality would involve the purification of the starting feedstock from impurities. [ABSTRACT FROM AUTHOR]

Poly(lactic-co-glycolic acid) (PLGA) is a widely used biodegradable and biocompatible copolymer in drug delivery systems (DDSs). In this article, we highlight the critical physicochemical properties of PLGA, including its molecular weight, intrinsic viscosity, monomer ratio, blockiness, and end caps, that significantly influence drug release profiles and degradation times. This review also covers the extensive literature on the application of PLGA in delivering small-molecule drugs, proteins, peptides, antibiotics, and antiviral drugs. Furthermore, we discuss the role of PLGA-based DDSs in the treating various diseases, including cancer, neurological disorders, pain, and inflammation. The incorporation of drugs into PLGA nanoparticles and microspheres has been shown to enhance their therapeutic efficacy, reduce toxicity, and improve patient compliance. Overall, PLGA-based DDSs holds great promise for the advancement of the treatment and management of multiple chronic conditions. [ABSTRACT FROM AUTHOR]

A range of new fluorine‐containing copolyarylates were successfully produced through interfacial polymerization using hexafluorobisphenol A (BPAF) featuring a symmetric trifluoromethyl group structure, bisphenol B (BPB), and two acyl chloride monomers as raw materials. The results indicated that the synthesized amorphous copolyarylates exhibited good solubility, with number average molecular weights (Mn) of 19,000–44,000 g/mol, weight average molecular weights (Mw) of 66,000–159,000 g/mol, and intrinsic viscosities of 0.66–1.19 dL/g. The thermal stability of copolyarylates increased with the increase of BPAF monomer content (0~100%), which was manifested by the linear increase of glass transition temperature (Tg) from 201.6 to 237.1°C, and the increase of 5% thermogravimetric weight loss temperature (T5%) from 474.1 to 491.5°C. The tensile strength of copolyarylates ranged from 52.63 to 59.93 MPa, the tensile modulus ranged from 1102.08 to 1502.84 MPa, and the elongation at break ranged from 32.0 to 75.5%. In addition, the copolyarylates had good dielectric properties with a dielectric constant of 2.58–3.75 at 107 Hz and a dielectric loss tangent of 0.021–0.028. [ABSTRACT FROM AUTHOR]

Few studies reported the impact of hydrocolloid addition on starches after heat moisture treatment (HMT). In this study, potato starch is modified by HMT under different moisture content (18–35%), and the impact of konjac glucomannan (KGM) addition on the pasting, gel texture, and rheological properties of potato starch after HMT are investigated. The results showed that after HMT, the granule structure of the starch is changed with higher heat stability, shown as higher pasting temperature and trough viscosity. The impact of KGM addition is similar on the potato starch before and after HMT, but the change extent of the latter is larger in most cases, such as decreased pasting temperature and gel hardness, increased peak viscosity, breakdown viscosity, and final viscosity. This indicated that KGM benefited the gelatinization behavior of HMT starch but might not enhance the retrogradation process. The intrinsic high viscosity of KGM in water resulted in a softer starch gel and also contributed to the enhanced shear stress of the mixture paste. Therefore, the impact of KGM on the HMT starch is more significant than the original starch, and this guided the use of HMT starch in the food industry with other hydrocolloid involvement. [ABSTRACT FROM AUTHOR]

Background: Chitosan due to biodegradable and non-toxic characteristics has versatile applications. Extraction and characterization of Chitosan from Snail Shells In January, 2023 Achatina fulica was performed. Methods: A chemical process involving demineralization and deproteinization was utilized to extract 2000g Chitin from Achatina fulica shells. To produce chitosan, the chitin was subjected to deacetylation. The chitosan was subsequently characterized using Fourier Transform Infrared spectroscopy, X-ray diffraction, and Scanning Electron Microscopy. The physicochemical charactristics and mineral compositionswere investigated and the data were analyzed using the Statistical Package for Social Sciences (SPSS) software version 20.0. Results: The chitosan obtained from the process was 75%. It exhibited a Degree Of Deacetylation of 82.31%, a molecular weight of 2.65×105 g/mol, an intrinsic viscosity of 1,007.2 mg/g, and a solubility of 70%. The pH value of chitosan in acetic acid solution was recorded at 6.38, with a solubility of 70%. The proximate analysis revealed moisture, ash, fat, protein, crude fiber, and carbohydrate contents of 0.32, 0.72, 2.01, 0.13, 0.15, and 96.67%, respectively. The mineral analysis revealed sodium, potassium, calcium, magnesium, phosphorus, iron, and zinc concentrations of 32.10, 21.80, 721, 288.60, 123.75, 41.77, and 8.48 mg/g, respectively. X-ray diffraction analysis identified the region characterized by the presence of calcite and calcium phosphate, indicating residual minerals in the extracted chitosan, which contribute to its crystalline structure. Fourier Transform Infrared spectroscopy demonstrated functional groups such as amino and hydroxyl groups, whereas Scanning Electron Microscopy reported an irregular particle size with rough surfaces and a microfibrillar crystalline structure. Conclusion: The current investigation has the potential to promote the sustainable use of a locally abundant yet underutilized resource, assisting in waste reduction and creation of innovative bioactive materials which could be applied in food preservation, pharmaceuticals, and medical devices. [ABSTRACT FROM AUTHOR]

Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & 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.)

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher 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.)

Deep eutectic solvents (DESs) offer an appealing green medium for the activation of cellulose fibres to promote their swelling, reactivity, hydrolysis, disintegration, and solubility for further processing. Typically, DES treatments are carried out below 5 wt% consistency even though a higher solids content could enhance the fibre activation and reduce the solvent consumption. In this work, a high-consistency (HC) mechano-chemical activation of bleached softwood kraft pulp was elucidated using a simultaneous fibre treatment with DES of choline chloride-urea and a sigma-type kneader or a twin-screw extruder at a solids content of 15–35 wt% and 30 wt%, respectively. Both HC treatments efficiently triggered fibre swelling, which was indicated by an increase in the fibre width, and loosened the cell wall structure which was indicated by an increase in the mesopore volume. Mechano-chemical HC processing generated fibre fines and external fibrillation, while the molecular-level structural alteration or changes in chemical composition were minor; the intrinsic viscosity and the crystallinity of the pulp remained at their initial level and only a small amount of xylan was dissolved. Overall, HC treatment in a twin-screw extruder caused notably more severe morphological changes in the fibres than batch treatment in a sigma-type kneader. Thus, the mechano-chemical HC treatment with DES provides an industrially relevant technology for cellulose modification and opens possibilities to enhance heterogeneous cellulose modification processes in which the highly available surface area of pulp is a key parameter. [ABSTRACT FROM AUTHOR]

There are difficulties in measuring the molecular weight (Mw) of bacterial cellulose (BC) using Gel Permeation Chromatography (GPC) analysis. Additionally, the Mark-Houwink-Sakurada equation cannot be used to predict the Mw of BC as no Mark-Houwink-Sakurada constant specific to BC is available. In this study, a systematic approach is developed to establish the relationship between the Mw of BC and the viscosity of its copper (II) ethylenediamine (CED) solutions. Impurities contained in the raw BC are examined and appropriate purification procedures are designed for their removal before the above two measurements are conducted. The Mw of BC is obtained by measuring the Degree of Polymerization of its corresponding cellulose acetate (CA), derived from degraded BC, using GPC analysis, and the viscosity of the CED solutions of the BC is measured using a BS/U Tube viscometer. In this paper, the Mark–Houwink–Sakurada constants (K=0.3752 mL/g and α =1.4532) specific for BC are determined to relate the Mw of BC with the intrinsic viscosity of its CED solutions. It is also found that the Mw of BC is proportional to the dynamic viscosity (i.e., η BC = 0.0183 M w 1.3069 ) and the flow time (i.e., t BC = 1.3809 Mw 1.3062 ) of its CED solutions. These BC-specific relationships can help determine the Mw of BC from the rheological properties of its CED solutions. [ABSTRACT FROM AUTHOR]

This work focused on the characterization of lignin residues from bioethanol production of olive stones (OS) and the use of these residues to chemically thicken epoxidized linseed oil (ELO). OS were processed by an acid/steam explosion pretreatment, followed by pre-saccharification, using different enzyme dosages, and simultaneous saccharification and fermentation. The chemical composition of the OS lignin residues was analysed, revealing a high lignin content (66.6–69.5%), and lower quantities of glucan (17.4–19.3%) and xylan (2.8–2.9%). Whereas, the structural properties of OS lignin residues were characterized by Fourier-transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), thermogravimetric analysis and size exclusion chromatography (SEC). OS lignin residues displayed the main inter-unit linkages (β–β′ resinol (51.0–59.0%), followed by β-O-4′ alkyl aryl ethers (27.0–35.2%) and β-5′ phenylcoumaran (11.4–13.2%) substructures), high molecular weights (22,000–25900 Da), low S/G ratios (1.2–1.5) and phenolic groups content (48–55 mg GAE/g lignin). Moreover, OS lignin residues were dispersed in ELO to obtain thickened formulations, which were characterized by FTIR and NMR. Oil thickening was achieved by promoting the chemical crosslinking between lignocellulose hydroxyl groups and ELO epoxy groups, enabling the compatibilization of both components. Up to tenfold viscosity increment of the resulting thickened formulations in relation to ELO's viscosity was observed. Besides, thickened formulations exhibited viscoelastic properties, evincing oil structuration to some extent. [ABSTRACT FROM AUTHOR]

Copyright of Advanced Textile Technology is the property of Zhejiang Sci-Tech University Magazines 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.)

It is imperative to improve the physical, morphological, and mechanical properties of biodegradable polymers like polylactic acid (PLA), poly (butylene adipate‐co‐terephthalate) (PBAT), and polycaprolactone (PCL) in order to employ them on a larger scale. The development of hybrid nanocomposite materials using nano inclusions can improve desired qualities. Here we introduced an interactive nano reinforcement approach to improve the properties by combining graphene oxide (GO) and carboxyl functionalized MWCNT (f‐MWCNT), to provide for their chemical bonding for synergic reinforcement. A constant filler 2 wt.% was added to the biopolyesters by melt blending process and examined the different physical properties like water absorption, intrinsic viscosity, and hardness. To completely evaluate the functionalization of the nanofillers, wide‐angle X‐ray diffraction (WAXD), Raman spectroscopy and Fourier transform infrared radiation (FTIR) analyses were used. The paired nanoparticles and polymer matrix appear to mix well together, as shown by electron microscopy, which also reveals good dispersion and the creation of a reinforcing network microstructure across the matrix layer. A thorough analysis of the results showed that effective stress transmission, delaying the start of faults and generating microcracks, and dissipating additional mechanical energy all contributed to efficient hybrid network formation, which improved the mechanical properties of hybrid filler nanocomposites except some nanocomposites. These findings offer a viable technique for chemically altering biodegradable polymers, like PLA, PBAT, and PCL for use in biomedical, wastewater management, and agricultural applications. [ABSTRACT FROM AUTHOR]

This study investigates the properties of solution-processed hybrid polyimide (PI) nanocomposites containing a variety of nanofillers, including polyaniline copolymer-modified clay (PNEA), nanographene sheets (NGSs), and carbon nanotube sheets (CNT-PVDFs). Through a series of experiments, the flow behavior of poly(amic acid) (PAA) solution and PAA suspension containing polyaniline copolymer-modified clay (PNEA) is determined as a function of the shear rate, processing temperature, and polymerization time. It is shown that the neat PAA solution exhibits a complex rheological behavior ranging from shear thickening to Newtonian behavior with increasing shear rate and testing temperature. The presence of modified clay in PAA solution significantly reduced the viscosity of PAA. Differential scanning calorimetry (DSC) analysis showed that polyimide–nanographene sheet (PI NGS) nanocomposites processed at a high spindle speed (100 rpm) have lower total heat of decomposition, which is indicative of improved fire retardancy. The effect of processing temperature on the specific capacitance of a polyimide–CNT-PVDF composite containing electrodeposited polypyrrole is determined using cyclic voltammetry (CV). It is shown that the hybrid composite working electrode material processed at 90 °C produces a remarkably higher overall stored charge when compared to the composite electrode material processed at 250 °C. Consequently, the specific capacitance obtained at a scan rate of 5 mV/s for the hybrid nanocomposite processed at 90 °C is around 858 F/g after one cycle, which is about 6.3 times higher than the specific capacitance of 136 F/g produced by the hybrid nanocomposite processed at 250 °C. These findings show that the properties of the hybrid nanocomposites are remarkably influenced by the processing conditions and highlight the need for process optimization. [ABSTRACT FROM AUTHOR]

An experiment designed to predict the lifetime of the Xuan paper using the viscosity method is introduced in the form of group collaboration. This experiment is targeted at junior students who majored in conservation of cultural relics, with eight groups involved. Using a jacketed viscometer, the intrinsic viscosity of the two types of undegraded and degraded Xuan papers was determined, and the corresponding degree of polymerization (DP) was calculated. Then data were collected from all groups, and degradation rates of the papers were then calculated, which were then used to predict the life expectancy of the Xuan papers. The aim was to enhance students’ teamwork skills, practical experience, problem-solving abilities, data analysis, and scientific research capabilities, while also guiding them to apply their chemical knowledge to practical conservation for paper-based objects. [ABSTRACT FROM AUTHOR]

The widely used weakly compressible variant of Smoothed Particle Hydrodynamics (SPH) method suffers from density and hence pressure oscillations. This is due to the particle Lagrangian nature of the SPH method in combination with weakly compressible assumption, explicit time scheme and that the substitutions of the derivatives in the SPH method are central. There are two common strategies how to suppress these issues. One of them is to use numerical diffusive term which is added to the continuity equation in order to suppress the spurious oscillation of density field. The second option is to describe the particle-particle interaction in terms of Riemann problem and use Riemann solver, which provides numerical dissipation, to handle particle interactions. In our work, we deal with the relation between these two approaches. For the constant reconstruction and for the linear reconstruction we show that the usage of Riemann solvers is due to its intrinsic numerical viscosity equivalent to the usage of diffusive terms based on even derivatives, with the difference that the Riemann solvers lead to a significantly higher diffusivity value then the standard diffusive terms. We also discuss the usage of limiters for cases with the linear reconstruction of the solution. Moreover, for both, the constant and the linear reconstruction, we analyze additional terms resulting from the employed Riemann solver also for the momentum equation. Combining these results we obtain equivalent partial differential equations, which are the result of the usage of the Riemann solver. • We show that Riemann based SPH is equivalent with the δ -WCSPH and they differ only in the diffusive coefficient. • We show additional resulting terms which are generated by the used Riemann scheme. [ABSTRACT FROM AUTHOR]

The study of the dynamics of nucleic acids in solution, their flow properties, and viscoelasticity is of great importance for understanding their biological functions. Many important properties of nucleic acids, such as DNA, depend on polymer concentration, CDNA, molecular weight (MW), rigidity, and external salt content, the latter parameter affecting electrostatic interactions. Furthermore, DNA molecular chains can organize, in vitro, into liquid crystalline phases at high CDNA. In this work, three DNA samples with different MW were studied in solution in a broad concentration range (CDNA from 0.025 to 200 mg mL−1, depending on DNA MW). Firstly, the intrinsic viscosities and MW for all DNA samples were determined through capillary and rheological measurements. Then, the overlap concentrations, C*, were estimated from the relation C* ≈ [η]−1. DNA chain characteristics were then analyzed in terms of the influence of DNA MW on the solution viscosities and on the overlap parameter, CDNA[η]. Flow birefringence appearance was identified by screening a wide CDNA range through visual observations with crossed polarizers. Finally, crossed‐light polarized microscopy was used to identify the appearance of liquid crystals at rest, confirming that higher CDNA are needed to obtain liquid crystals for low MW DNA samples. [ABSTRACT FROM AUTHOR]

Commercial low acyl gellan (LAG) is purified by the fractional dissolution method. An aqueous solution of purified commercial LAG exhibits polyelectrolyte character due to its high molar mass and carboxylic groups in glucuronic acid fragments. The empirical Fuoss equation determines the intrinsic viscosity of purified LAG in salt‐less water. Fractionation of commercial LAG is carried out by ultrasound treatment. LAG fractions are characterized by 1H NMR and FTIR spectroscopy. The intrinsic viscosities of ultrasonically treated LAG samples are measured in 0.025 m of tetramethylammonium chloride (TMACl). The molecular weights of LAG fractions are determined by the Mark–Kuhn–Houwink equation. [ABSTRACT FROM AUTHOR]

In order to explore the changes in the performance of polyester fibers prepared by different processes under alkaline conditions, high tenacity (HT) polyester industrial fiber and fully drawn polyester yarn (FDY) of high speed spinning were selected for artificial accelerated aging tests in alkaline conditions at 85 °C. The mechanical properties of fibers were tested during the processes. Wide-angle X-ray diffraction, small-angle X-ray scattering and intrinsic viscosity were used to study the change in crystalline, lamellar structure and chemical structure of polyester fibers. The results showed that the changes in structure and properties of two polyester fibers in alkaline conditions can be divided into three stages. At the initial stage, the breaking strength and degree of orientation of the fibers first decreased significantly due to the effect of water and heat, while crystallinity remained constant. It was caused by the disorientation of amorphous orientated molecular chain segments in the frozen state, resulting in shrinkage. Then the decrease in breaking strength of fibers was slowed down, which was attributed to the breakage of amorphous molecular chains and the formation of a few new crystal structures. In the final stage of alkaline hydrolysis, the breaking strength of the fibers decreased significantly, while the crystallinity of fibers began to decline and the intrinsic viscosity reduced constantly, indicating that the breakage of amorphous molecular chain became the dominant factor. The alkaline hydrolysis reaction rate and the change degree of microstructure and mechanical property parameters of HT fibers were lower than those of FDY fibers, owing to the greater crystallinity and crystal size of HT fibers, which inhibited the erosion of water and OH-. As a result, HT fibers had a better alkaline hydrolysis resistance than FDY fibers. [ABSTRACT FROM AUTHOR]

Poly(ethylene terephthalate) (PET), both bottle grade (PET‐B) and thermoform grade (PET‐T), are widely used in the packaging sector. However, only PET‐B is recycled and reused, while PET‐T needs to be separated from recycled PET bales. This study aims to assess the impact of solid‐state polymerization (SSP), chain extension and the combination of chain extension–SSP to transform PET‐B and PET‐T blends into PET‐T‐like material. The intrinsic viscosity (IV) values for PET‐B blends with 10–20 wt% of PET‐T are measured for the samples obtained in this study. The mechanical properties, such as tensile strength, modulus, elongation and impact strength, were also determined. The glass transition temperature, melting temperature, crystallinity and thermal degradation were also investigated. The findings suggest that the combination of SSP and chain extension leads to a significant improvement in IV and tensile strength, while SSP alone is less suitable to offer the desired IV values. © 2024 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

The two Large Low Velocity Provinces (LLVPs) in the lowermost Earth mantle are thought to affect large‐scale heat and material transport, governing mantle evolution. LLVPs have been interpreted as thermochemical piles of recycled oceanic crust (ROC) and/or other dense rock types. However, the role of ROC intrinsic viscosity in pile formation and related effects on mantle evolution remain poorly understood. Using mantle convection models, we show that, while ROC intrinsic density controls pile formation, intrinsic viscosity determines whether piles are internally convecting or stratified. Only high‐viscosity, stratified piles can preserve material over several billions of years. Pile stratification is therefore required to reconcile geochemical evidence for the survival of ancient reservoirs. Compositionally layered piles are also consistent with geophysical observations that point to vertical gradients in LLVP properties. As mineral physics constraints point to low‐viscosity ROC, our results suggest that LLVPs may be partly formed by early basal‐magma‐ocean cumulates. Plain Language Summary: Earthquake‐produced vibrations travel long distances inside the Earth, but slow down when they cross two large blobs that lie thousands of kilometers below Africa and the Pacific Ocean. The nature of these anomalies is controversial, but it is thought that the crust, the outermost rocky peel that is continuously formed on the Earth's surface, may penetrate the planet's interior, sink and accumulate to form large piles. We employ a specialized code that is widely used to simulate movements of masses inside rocky planets over billions of years, including the process of crust formation and accumulation. We experiment with how dense and soft/strong (i.e., easy/hard to deform) this sunken crust is, relative to the surroundings. We investigate how these largely unknown properties affect pile formation and find that crustal strength has a marginal role compared to its density. However, only high strength makes piles layered and able to store ancient material, consistent with current observations. As recent laboratory experiments point to a soft crust, our results suggest that the piles observed today mainly contain "primitive" material that settled in the deep Earth during the very early stages of our planet's formation, instead of crust. Key Points: Intrinsic viscosity of deep‐sunken oceanic crust does not affect its segregation and accumulation into pilesHigh‐viscosity piles are stratified and able to store Archean‐age materialsLarge low velocity provinces may not be mainly formed of low‐viscosity oceanic crust [ABSTRACT FROM AUTHOR]

Protein‐based hydrogels have great potential to be used as bioinks for biofabrication‐driven tissue regeneration strategies due to their innate bioactivity. Nevertheless, their use as bioinks in conventional 3D bioprinting is impaired due to their intrinsic low viscosity. Using embedding bioprinting, a liquid bioink is printed within a support that physically holds the patterned filament. Inspired by the recognized microencapsulation technique complex coacervation, crystal self‐healing embedding bioprinting (CLADDING) is introduced based on a highly transparent crystal supporting bath. The suitability of distinct classes of gelatins is evaluated (i.e., molecular weight distribution, isoelectric point, and ionic content), as well as the formation of gelatin‐gum arabic microparticles as a function of pH, temperature, solvent, and mass ratios. Characterizing and controlling this parametric window resulted in high yields of support bath with ideal self‐healing properties for interaction with protein‐based bioinks. This support bath achieved transparency, which boosted light permeation within the bath. Bioprinted constructs fully composed of platelet lysates encapsulating a co‐culture of human mesenchymal stromal cells and endothelial cells are obtained, demonstrating a high‐dense cellular network with excellent cell viability and stability over a month. CLADDING broadens the spectrum of photocrosslinkable materials with extremely low viscosity that can now be bioprinted with sensitive cells without any additional support. [ABSTRACT FROM AUTHOR]

Poly(ethylene 2,5-furandicarboxylate) (PEF) is an important biobased polyester with better thermal, mechanical, and gas barrier properties than poly(ethylene terephthalate). In PEF synthesis, diethylene glycol furandicarboxylate (DF) is inevitably formed via etherification side reaction. Taking advantage of the side reaction, poly(ethylene-co-diethylene furandicarboxylate) (PEDF) poly(etherester)s were synthesized only from 2,5-furandicarboxylic acid (FDCA) and ethylene glycol (EG), using a cheap binary propanedisulfonic acid/dibutyltin oxide (PSA/DBTO) catalyst. The polymers were characterized by 1 H NMR, intrinsic viscosity, solubility, differential scanning calorimetry, thermogravimetric analysis, tensile, and gas barrier test. Due to strong acidity of PSA, not only major DF but also minor oligoethylene glycol furandicarboxylate ethercontaining units were formed. Their total content can be adjusted up to 78 mol % by simply increasing the dosage of PSA from 0 to 0.4 wt%. The effect of ether-containing units on the solubility, thermal transition, mechanical, and oxygen barrier properties of the poly(ether-ester)s were examined and compared with the poly(ether-ester)s synthesized via copolycondensation. [ABSTRACT FROM AUTHOR]

In view of the high content of adsorbed gas in shallow normal-pressure shale gas, which is difficult to increase production and achieve effective exploitation, and the difficulty of natural degradation of conventional polymer drag reducer, oil-free lotion drag reducer was synthesized through aqueous dispersion polymerization. using friction meters, magnetic levitation balances, etc to evaluate the performance of drag reducer and their formed slick water systems The experimental results show that the laboratory resistance reduction rates of the 0.6% to 1.0% resistance reducing water system prepared with this resistance reducing agent are all above 70%, on site drag reduction rate of 84%. The desorption experiment results show that the desorption rate of the product reaches 85%, which is much higher than the conventional lotion drag reducer product. The natural degradation ability of the drag reducer was evaluated using the intrinsic viscosity method, and it was found that it can achieve natural degradation at 95 č in 330 hours, with a degradation rate of 86%. The core damage rate is much lower than that of the guanidine gum system, and the IC50 test results show that the drag reducer is non-toxic and environmentally friendly at the concentration of use. This provides technical reference and new product ideas for the development of shallow atmospheric shale gas. [ABSTRACT FROM AUTHOR]

Linear polyacrylamide (LPA) was synthesized through an oxidation-reduction initiator system in aqueous solution. Linear polyacrylamide/poly(N, N-dimethylacrylamide) (LPA/PDMA) and linear polyacrylamide/poly(N-hydroxyethyl acrylamide) (LPA/PHEA) quasi-interpenetrating polymer networks were synthesized by polymerizing N, N-dimethylacrylamide (DMA) and N-hydroxyethyl acrylamide (HEA) in LPA aqueous solution, respectively. Characterization techniques, including ¹H-Nuclear Magnetic Resonance Spectra (¹H-NMR), Fourier Transform Infrared Spectrometer (FT-IR), and Differential Scanning Calorimetry (DSC), were employed to analyze the structures. The intrinsic viscosity of LPA, LPA/PDMA and LPA/PHEA were determined using a Ubbelohde viscometer, and the viscosity average molecular weight (Mη) was calculated based on the intrinsic viscosity. The rheological properties of the above quasi-interpenetrating polymer networks were systematically investigated, focusing on the effects of LPA intrinsic viscosity molecular weight, shear rate, temperature, and other factors. When the mass concentration of polymer(ρ) is less than the critical entanglement concentration(ρ*), the specific viscosity(ηsp) of LPA solution increases slowly with ρ. When ρ is more than ρ*, ηsp increases rapidly with ρ. And ρ* of LPA solution decreases as molecular weight increases. LPA, LPA/PHEA, and LPA/PDMA solutions exhibit significant shear-thinning behavior, and the apparent viscosity(η) of LPA/PHEA and LPA/PDMA solutions is significantly lower than that of the corresponding LPA solution. The η of polymer solutions decreases with increasing temperature, and LPA/PHEA and LPA/PDMA are more temperature-sensitive. The viscoelastic results show that in the linear viscoelastic region, at a mass concentration of 0.025 g/mL, polymer solutions based on medium and high molecular weight LPA are predominantly elastic, indicating a relatively stable polymer network structure, while those based on low molecular weight LPA are predominantly viscous, indicating that the polymer network structure is unstable and easily disrupted by external forces. [ABSTRACT FROM AUTHOR]

γ-Valerolactone (GVL) is a promising biomass-based platform compound that can be used for the removal of hemicellulose in pulp. In this study, a paper-grade pulp was treated using GVL to generate dissolving pulp for viscose production. The GVL concentration, treatment temperature, and reaction time had significant effect on the hemicellulose dissolution. The dissolving pulp with a-cellulose content of 92.3% and hemicellulose content of 5.45% was achieved with 60% GVL at 120 °C for 2 h. The Fock reactivity and intrinsic viscosity of the obtained dissolving pulp were 54.6% and 595 mL/g, which is comparable with the commercial product. In addition, GVL spent liquor was also recycled and reused to upgrade paper-grade pulp. By using purified recycled GVL to treat original pulp, the Fock reactivity of pulp was improved, and the cellulose content of asprepared upgraded pulp increased to 92.1%, which was close to the cellulose content of dissolving pulp obtained from fresh GVL solution, while the intrinsic viscosity decreased significantly to 598 mL/g. Therefore, the efficient reuse of GVL not only ensured the high quality of dissolving pulp, but it also saved production costs and reduced environmental pollution. [ABSTRACT FROM AUTHOR]

Statistical learning is employed to present a principled framework for the establishment of quantitative structure‐property relationships (QSPR). Property predictions of industrial polymers formed by multiple reagents and at varying molecular weights are focused. A theoretical description of QSPR as well as a rigorous mathematical method is developed for the assimilation of experimental data. Results show that these methods can perform exceptionally well at establishing QSPR for glass transition temperature and intrinsic viscosity of polyesters. [ABSTRACT FROM AUTHOR]

Understanding the motion of nanoparticles in liquid is of practical importance for drug delivery and fluid flow in nanofluidic systems. In this work, we use a nanoparticle tracking analyzer to investigate the Brownian motion of polydivinylbenzene (PDVB) nanoparticles in water and a video camera to record the aggregation of PDVB aggregates on the water surface. Using water as the liquid medium precludes the possible complex interaction between the liquid medium and the PDVB nanoparticles, which can possibly alter the random characteristics of the motion of the PDVB nanoparticles. The diffusivity of the PDVB nanoparticles determined from the mean square displacements of the PDVB nanoparticles has the same activation energy as that for the intrinsic viscosity of the corresponding aqueous suspension of the PDVB nanoparticles. The correlation between the diffusivity for the motion of the PDVB nanoparticles in water and the intrinsic viscosity of the corresponding aqueous suspension follows the Stokes–Einstein relation. The capillary effect and the interaction between PDVB aggregates and the liquid media enable the aggregation of the PDVB aggregates on the water surface, which follows the first-order reaction with activation energy larger than that for the random motion of the PDVB nanoparticles in water. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) is used in a variety of packaging applications, such as bottles, films, fibers, for its cost‐effective and excellent physical properties. However, the increase in plastic usage and packaging waste has become major global problems. Therefore, the importance of plastic recycling is being emphasized. In this study, the bottle‐grade PET was repeatedly melt processed up to three times to evaluate of PET recyclability. Intrinsic viscosity (IV) and mechanical properties have significantly decreased due to chain scission during the melt reprocessing. In particular, the IV of 3rP (reprocessing three times) decreased to 0.582 dL/g, and the mechanical properties decreased more than twice compared with 0rP. To enhance the physical properties of reprocessed PET (rP‐PET), it was modified using two chain extenders. The IV of the modified 3rP‐PET increased from 0.645 to 0.737 dL/g. And the tensile strength was improved up to approximately 93% of the 0rP properties, confirming the chain extension effect. Additionally, a biaxial orientation process was applied to confirm the feasibility of modified rP‐PET to various industrial packaging applications. Consequently, as the stretching ratio increased, the physical properties of modified rP‐PET improved, confirming the feasibility of rP‐PET in various packaging fields. [ABSTRACT FROM AUTHOR]

In this article, the synthesis of four novel bioelastomers known as poly (xylitol sebacate) (PXS), poly (xylitol adipate) (PXA), poly (sorbitol sebacate) (PSS), and poly (sorbitol adipate) (PSA) was carried out through bulk polymerization, followed by their blending using the solution method. Six blends were prepared namely PXS25/PSS75, PXS50/PSS50, PXS75/PSS25, PXS50/PXA50, PSA50/PXA50, and PSS50/PSA50. After blending, a thermal curing process was applied to the samples. The intrinsic viscosity, density, Tg, hydrophilicity, degradation, wound healing, and mechanical properties of polymers and blends were measured to investigate the effects of blending. Analyzing hardness, modulus, stress at breakpoint, degradation, and hydrophilicity data showed that the mechanical properties of bioelastomers are adjustable by blending for tissue engineering. Furthermore, the scratch assay proved the biocompatibility of pure polymers and indicated that blending does not have a negative impact on this matter. [ABSTRACT FROM AUTHOR]

This article presents a novel material of acrylamide (AM) cross‐linked psyllium polysaccharides (PLP) derivative, PLP‐AM, which can be used as an effective polymeric flocculant for the removal of microplastics (MP) from water. PLP‐AM was produced by radical polymerization of PLP and AM using microwave irradiation instead of conventional radical initiators. The characterization of PLP‐AM was carried out by FT‐IR spectroscopy, elemental analysis, intrinsic viscosity measurement and thermogravimetric analysis (TG). Polystyrene (PS), polyethylene terephthalate (PET) and polyvinyl chloride (PVC) were utilized to examine the flocculation performance of PLP‐AM. The optimum flocculation conditions were obtained by the comprehensive exploration of flocculant concentration, solution pH and temperature. In a solution with a pH 6 at 30 °C, the maximum removal percentages of PS and PVC by 60 mg/L of PLP‐AM were 92.55 % and 94.31 %, respectively, while 93.85 % of the maximum removal of PET percentage could be obtained by 80 mg/L of PLP‐AM. The results of zeta potential measurement revealed that there was adsorption electric neutralization between MP and PLP‐AM besides the adsorption bridging mechanism. These results suggest that PLP‐AM may bring an inspiration for the development of polymer flocculant to remove MP from water. [ABSTRACT FROM AUTHOR]

Ionically conductive polymers highly filled with active materials, such as metal oxides are increasingly studied for their potential use in all solid‐state batteries. They offer the desirable processing ease of polymers for mass production despite interfacial issues that remain to be solved. In this study, it is shown that spherical particles of transition metal oxides can be introduced in co‐polymers of alkene carbonate and ethylene oxide at loading close to the maximum packing fraction, without imparting the processability in the melt of the material. In particular, the viscosity does not show any yield stress and the increase of viscosity shows that the intrinsic viscosity of the filler does not match with the usual 2.5 value in the limit of the Einstein's equation. Conversely, rheological data show that the value is rather close to unity consistently with theoretical arguments that predicted that this scaling factor should be unity when particle rotation is precluded. In the present case, this behavior is attributed to strong bonding between polymer and filler that is proved by electronic microscopy and by dynamical mechanical spectroscopy showing a relaxation due to bound polymer. [ABSTRACT FROM AUTHOR]

The thermal decomposition of the thermodynamic, kinetic and mechanisms of copolymer P(DAC-AM) samples with serial cationicity and intrinsic viscosity ([η]), and the control samples of homopolymer PAM and PDAC, were studied and analyzed using TG, DSC, FTIR. The results of the thermal decomposition thermodynamics confirmed that the thermal decomposition processes of the serial P(DAC-AM) samples and the two control samples could be divided into two stages. It was found that the processes of the copolymer P(DAC-AM) samples were not a simple superposition of those of homopolymers, whose monomers had composed the unit structures of the copolymer, but there were interactions between the two suspension groups. The results of thermal decomposition kinetics showed that the apparent activation energy (E) of the thermal decomposition process of all polymer samples had different varying trends in the terms of weight-loss rate (α). The reaction order (n) of the thermal decomposition of P(DAC-AM) in Stage I and II was close to 1, but in the former and the latter it tended to be 2 and 0.5, respectively. Finally, the thermal decomposition mechanism of copolymer P(DAC-AM) samples was discussed. The above research could not only fill in the knowledge vacancy of the thermal decomposition of the thermodynamic, kinetic and mechanisms of P(DAC-AM), but could also lay a foundation for the study of thermal decomposition mechanisms of the other types of polymers, including cationic polymers. [ABSTRACT FROM AUTHOR]

Several series of new polymers were synthesized in this study: binary copolyesters of vanillic (VA) and 4′-hydroxybiphenyl-4-carboxylic (HBCA) acids, as well as ternary copolyesters additionally containing 4-hydroxybenzoic acid (HBA) and obtained via three different ways (in solution, in melt, and in solid state). The high values of logarithmic intrinsic viscosities and the insolubility of several samples proved their high molecular weights. It was found that the use of vanillic acid leads to the production of copolyesters with a relatively high glass transition temperature (~130 °C). Thermogravimetric analysis revealed that the onset of weight loss temperatures of ternary copolyesters occurred at 330–350 °C, and the temperature of 5% mass loss was in the range of 390–410 °C. Two-stage thermal destruction was observed for all aromatic copolyesters of vanillic acid: decomposition began with VA units at 420–480 °C, and then the decomposition of more heat-resistant units took place above 520 °C. The copolyesters were thermotropic and exhibited a typical nematic type of liquid crystalline order. The mechanical characteristics of the copolyesters were similar to those of semi-aromatic copolyesters, but they were much lower than the typical values for fully aromatic thermotropic polymers. Thus, vanillic acid is a mesogenic monomer suitable for the synthesis of thermotropic fully aromatic and semi-aromatic copolyesters, but the processing temperature must not exceed 280 °C. [ABSTRACT FROM AUTHOR]

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