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The interfacial structure and binding forces of polytrimethylene terephthalate/polyethylene terephthalate filament were investigated through the methods of Carbon-13 nuclear magnetic resonance (13C-NMR), differential scanning calorimeter (DSC), scanning electron microscopy (SEM) and optical microscopy. When two molten polymers met during the spinning process, an interface layer between the PTT and PET components formed and played an important role in binding the two components together. When the blending time was sufficient, an ester-interchange reaction took place with the generation of the copolymer. The PET recrystallisation was observed in the DSC curve under the influence of entangled PTT molecular chains. The morphology of the cross-section and side view proved that the linear boundary line was short and weaker in binding without a chemical bond and molecular diffusion. Side-by-side bi-component fiber and split-type fiber was able to be controllably spun by adjusting the spinning parameters. [ABSTRACT FROM AUTHOR]

This paper reports a study on producing admixtures from chitosan (Ch) obtained from shrimp shell treatment. The admixtures (Ch-g-AA) were based on chitosan (Ch) and acrylic acid (AA) in the following composition ratios: 65/35, 50/50, and 35/65. The grafted copolymers were synthesized using grafting polymerization and potassium persulphate as the initiator. This study investigated the properties of mortars in the presence of grafted copolymers, including setting time, workability, water absorption, and compressive strength. The results showed that grafted copolymers premixed with mortar mixes improved the properties of the mortar. However, increasing the AA ratio in the grafted copolymer decreased the W/C ratio, setting time, and water absorption, whereas the fluidity and compressive strength increased. [ABSTRACT FROM AUTHOR]

The objective of the current work was to demonstrate the equivalence of Mylan's glatiramer acetate (GA) to that of the reference product Copaxone® (COP) using the four criteria for active pharmaceutical ingredient sameness as established by the US Food and Drug Administration (FDA). The reaction scheme used to produce Mylan's glatiramer acetate (MGA) was compared with that of COP, determined from publicly available literature. Comparative analyses of MGA and COP were performed for physicochemical properties such as amino acid composition and molecular weight distributions. Spectroscopic fingerprints were obtained using circular dichroism spectroscopy. Structural signatures for polymerization and depolymerization including total diethylamine (DEA) content, relative proportions of DEA-adducted amino acids, and N-and C-terminal amino acid sequences were probed with an array of highly sensitive analytical methods. Biological activity of the products was assessed using validated murine Experimental autoimmune encephalomyelitis (EAE) models of multiple sclerosis. MGA is produced using the same fundamental reaction scheme as COP and was shown to have equivalent physicochemical properties and composition. Analyses of multiple structural signatures demonstrated equivalence of MGA and COP with regard to polymerization, depolymerization, and propagational shift. Examination of the impact on prevention and treatment of EAE demonstrated equivalence of MGA and COP with respect to both activity and toxicity, and thereby provided confirmatory evidence of sameness. A rigorous, multi-pronged comparison of MGA and COP produced using an equivalent fundamental reaction scheme demonstrated equivalent physicochemical properties, structural signatures for polymerization and depolymerization, and biological activity as evidenced by comparable effects in EAE. These studies demonstrate the equivalence of MGA and COP, establishing active ingredient sameness by the US Food and Drug Administration (FDA) criteria for GA, and provide compelling evidence that the FDA-approved generic MGA can be substituted for COP for the treatment of patients with relapsing-remitting MS. [ABSTRACT FROM AUTHOR]

Poly(2-chloroaniline-co-2-ethylaniline)(poly(OCA-co-OEA)) was synthesized by in situ chemical oxidative method using ammonium per sulfate as an initiator and HCl as dopant. The copolymer was characterized by FTIR, UV-Visible, NMR spectroscopic techniques and XRD. FESEM and EDAX were taken to study the surface morphology and elemental composition. Thermal stability of the copolymer was confirmed by thermogravimetric analysis. The conduction was examined in terms of the dielectric constant and the electrical conductivity of 8.083 × 10–6 S cm−1 measured shows semi conducting nature of the emeraldine salt form of the copolymer. FESEM images show spongy and porous surface. The oxidation/reduction potentials and electrochemical reaction of Li/copolymer cells were tested by cyclic voltammetric technique. The discharge capacity of 63.4 mAh/g and charge capacity 62.8 mAh/g at 7–8 cycles show good reversibility. The practical specific charge capacity was 58.2% of the theoretical specific charge capacity which is 107.76 mAh/g. Hence it can efficiently be used as an anodic electrode material in lithium ion secondary batteries. [ABSTRACT FROM AUTHOR]

While higher high specific surface area allows micro-supercapacitor (MSC) electrode materials to have improved performance, it also tends to make them less stable thermodynamically and microstructurally, which can easily deteriorate and seriously affects their service life. So here, we have chosen a crosslinked copolymer film structure as MSC electrodes. The pyrrole-thieno [3,4-b] thiophene (TbT) copolymer film (namely PPy-co-TbT) exhibits high specific capacity, which can reach 47.8 mF cm-2 (a specific volumetric capacitance of 23.9 F cm-3 and a specific gravimetric capacitance of 28.1 F g-1) at a current density of 0.1 mA cm-2 using LiCl/PVA gel electrolyte with ultra-long cycling stability (capacitance retention after 50 000 charge/discharge cycles is still higher than 93%, which is the leading level in MSCs). The electrochemical performance of this cross-linked copolymer is superior to that of the singlecomponent polymer, achieving a 1 + 1 > 2 effect. Both features of crosslinking and copolymerization have positive effects on microelectrodes requiring stable microstructures and high performance. The structurally stable crosslinked copolymer obtained by copolymerization design may become a durable material for next generation ultra-long-life, high-performance microsupercapacitor electrodes and will be widely developed. [ABSTRACT FROM AUTHOR]

Poly (aniline-co-o-anisidine) of copolymer coating was synthesized on copper surface (Cu) in an aqueous solution containing 90 ml of 0.20 M NaOX + 10 ml of 0.20 M oxalic acid. The copper substrate in NaOX solution containing oxalic acid had a fairly reliable passive surface mainly due to the formation of copper (II) oxalate layer. The addition of oxalic acid to working electrolyte contributed to both the amount of copolymer deposition (growth) and that of copolymer coated per unit time of electropolymerization (growth rate). The corrosion performances of copolymer coatings were investigated in 3.5 % NaCl solution with anodic polarization curves and electrochemical impedance spectroscopy. The results showed that oxalic acid led to the diminishing of the permeability of copolymer film. The copolymer coating exhibited an effective barrier property on copper electrode and provided a remarkable anodic protection to substrate for longer exposure time. [ABSTRACT FROM AUTHOR]

Reinforcing thermoplastic polymers with natural fibres tends to improve tensile and flexural strength but adversely affect elongation and impact strength. This limits the application of such composites where toughness is a major criterion. In the present work, bamboo fibre reinforced polypropylene (PP) composites were prepared with bamboo fibre content varying from 30% to 50% with improved impact resistance. Homopolymer and copolymer PP were used as the matrix polymer and an elastomer was used (10% by wt.) as an additive in the formulation. Copolymer based composites exhibited superior elongation and impact strength as compared to homopolymer based composites. The adverse impact of elastomer on tensile and flexural strength was more pronounced in homopolymer based composites. The study suggested that the properties of the bamboo composites can be tailored to suit different applications by varying reinforcement and elastomer percentage. [ABSTRACT FROM AUTHOR]

The objective of the current work was to demonstrate the equivalence of Mylan’s glatiramer acetate (GA) to that of the reference product Copaxone® (COP) using the four criteria for active pharmaceutical ingredient sameness as established by the US Food and Drug Administration (FDA). The reaction scheme used to produce Mylan’s glatiramer acetate (MGA) was compared with that of COP, determined from publicly available literature. Comparative analyses of MGA and COP were performed for physicochemical properties such as amino acid composition and molecular weight distributions. Spectroscopic fingerprints were obtained using circular dichroism spectroscopy. Structural signatures for polymerization and depolymerization including total diethylamine (DEA) content, relative proportions of DEA-adducted amino acids, and N-and C-terminal amino acid sequences were probed with an array of highly sensitive analytical methods. Biological activity of the products was assessed using validated murine Experimental autoimmune encephalomyelitis (EAE) models of multiple sclerosis. MGA is produced using the same fundamental reaction scheme as COP and was shown to have equivalent physicochemical properties and composition. Analyses of multiple structural signatures demonstrated equivalence of MGA and COP with regard to polymerization, depolymerization, and propagational shift. Examination of the impact on prevention and treatment of EAE demonstrated equivalence of MGA and COP with respect to both activity and toxicity, and thereby provided confirmatory evidence of sameness. A rigorous, multi-pronged comparison of MGA and COP produced using an equivalent fundamental reaction scheme demonstrated equivalent physicochemical properties, structural signatures for polymerization and depolymerization, and biological activity as evidenced by comparable effects in EAE. These studies demonstrate the equivalence of MGA and COP, establishing active ingredient sameness by the US Food and Drug Administration (FDA) criteria for GA, and provide compelling evidence that the FDA-approved generic MGA can be substituted for COP for the treatment of patients with relapsing-remitting MS.

Poly(N-isopropylacrylamide-co-2-hydroxyethyl methacrylate) (poly(NIPAM-co-HEMA)) is a temperature-responsive copolymer that is expected to be applicable as an advanced functional polymeric material in various fields. In this study, a novel method was developed to control the responsive temperature of poly(NIPAM-co-HEMA) using an ultrasonic polymerization technique. Initially, the behavior of the reaction was investigated using NIPAM and HEMA monomers under ultrasonic irradiation. A high ultrasonic power was found to produce a high reaction rate and low number average molecular weight of the copolymer. The polydispersity of the synthesized copolymer was approximately 1.5 for all ultrasonic powers examined. In the early stage of the reaction, the molar fraction of NIPAM in the copolymer was lower than the initial molar fraction of the monomers. It was concluded that ultrasonic irradiation affected the initiation reaction and polymer degradation, but did not affect the propagation reaction. Furthermore, the effect of the ultrasonic irradiation conditions on the temperature responsiveness of the copolymer was investigated. The lower critical solution temperature (LCST) of the copolymer was found to increase with increasing ultrasonic irradiation time. In addition, in the early stages of the reaction, the measured values of the LCST were higher than the estimated values using copolymer composition. This can be attributed to some parts of the copolymer chain possessing a higher NIPAM fraction than the overall fraction due to different reactivities of the monomers and terminated radicals. This hypothesis was indirectly verified by the synthesis of a block copolymer from the PNIPAM homopolymer and HEMA monomer.

Tumor microenvironment–responsive polypeptide nanogels belong to a biomaterial with excellent biocompatibility, easily adjustable performance, biodegradability, and non-toxic properties. They are developed for selective delivery of antitumor drugs into target organs to promote tumor cell uptake, which has become an effective measure of tumor treatment. Endogenous (such as reduction, reactive oxygen species, pH, and enzyme) and exogenous (such as light and temperature) responsive nanogels can release drugs in response to tumor tissues or cells to improve drug distribution and reduce drug side effects. This article systematically introduces the research progress in tumor microenvironment–responsive polypeptide nanogels to deliver antitumor drugs and provides a reference for the development of antitumor nanoformulations.

A novel cellulose acetate-g-poly (2-acrylamido-2-methylpropane sulfonic acid-co- methyl methacrylate) copolymer was prepared via free radical polymerization for the first time. The chemical structure of the graft copolymer was confirmed using FT-IR, 1H NMR and EDX. The TGA and DSC investigated the thermal changes. Factors affecting the grafting process were studied and various grafting characteristic parameters such as grafting efficiency (%), grafting yield (%) and add-on value (%) were determined. Flexible membranes based on different graft copolymer compositions were fabricated by simple solution casting. Physicochemical properties including ion exchange capability (IEC), water uptake (WU) and proton conductivity (σ) were evaluated. These membranes demonstrated higher IEC, WU and conductivity than the pristine CA. The maximum proton conductivity of the CA-g-poly (2-acrylamido-2-methylpropane sulfonic acid-co- methyl methacrylate) copolymer membrane (68%; Add-on %) was found to be 6.44 × 10−3 S/cm compared with 0.035 × 10−3 S/cm of the pristine CA. Thus, the appropriate graft copolymer composition will allow fine-tuning of the physical characteristics and led to several potential applications, such as polyelectrolyte fuel cells membranes or biodiesel production.

Tumor microenvironment–responsive polypeptide nanogels belong to a biomaterial with excellent biocompatibility, easily adjustable performance, biodegradability, and non-toxic properties. They are developed for selective delivery of antitumor drugs into target organs to promote tumor cell uptake, which has become an effective measure of tumor treatment. Endogenous (such as reduction, reactive oxygen species, pH, and enzyme) and exogenous (such as light and temperature) responsive nanogels can release drugs in response to tumor tissues or cells to improve drug distribution and reduce drug side effects. This article systematically introduces the research progress in tumor microenvironment–responsive polypeptide nanogels to deliver antitumor drugs and provides a reference for the development of antitumor nanoformulations. [ABSTRACT FROM AUTHOR]

Ultra‐high temperature dramatically deteriorates rheological properties and filtration performance of water‐based drilling fluids (WBDFs), especially for a salt‐gypsum formation that greatly restricts the application of WBDFs in ultra‐deep well drilling operations. Hence, the research in this article used an anionic copolymer (DANS) prepared by N, N‐dimethylacrylamide, 2‐acrylamide‐2‐methylpropanesulfonic acid, N‐vinylpyrrolidone, and sodium 4‐styrenesulfonate as an anti‐ultra‐high temperature and anti‐salt contamination filtrate reducer. Due to its multiple bulky cyclic structures in the side chain, DANS exhibits excellent thermal stability in the thermal gravimetric, rheological, and filtration tests. By adding 1.0 wt% DANS, the American Petroleum Institute (API) filtration volume of sodium bentonite‐based fluids (SBT‐BFs) decreased from 56.0 to 9.2 ml after aging at 240°C. Even under both 20 wt% NaCl contamination and 240°C aging, SBT‐BFs with 2.0 wt% DANS could maintain a filtration volume of 9.4 ml, whereas SBT‐BFs without DANS reached a filtration volume of 203.0 ml. The possible filtration control mechanism of DANS was further investigated via the Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), ζ potential, particle size distribution, filter cake micro‐morphology, and transmission electron microscopy (TEM). Confirmed by FTIR and AFM results, the effective adsorption was formed between DANS and bentonite even under a high‐salinity environment. Thus, a firm "dot net" structure formed by bentonite/DANS was observed by TEM, significantly improving the colloidal stability, dispersibility, and filter cake compactness of SBT‐BFs. Finally, by utilizing DANS as the core treatment agent, a high‐density WBDFs system with a temperature resistance of 240°C and a salt‐tolerance of 20 wt% has been successfully prepared. [ABSTRACT FROM AUTHOR]

The thermal decomposition of polyethylene glycol fumarate–acrylic acid copolymer is investigated at different rates of heating. It is shown that increasing the rate of heating raises the temperature of the onset of decomposition. The kinetic parameters of decomposition are calculated using the integral Kissinger–Akahira–Sunose procedure. It is found that at different degrees of conversion, the activation energies are very close: E = 205–227 kJ/mol. The effect the composition of the copolymer has on the results from kinetic calculations is shown. The Coates–Redfern approach is used to determine the pre-exponential factor and the model of thermal decomposition. Calculated thermogravimetric curves are constructed and compared to experimental ones. [ABSTRACT FROM AUTHOR]

In this study, a light cross‐linkable biocomposite scaffold based on a photo‐cross‐linkable poly (propylene fumarate) (PPF)‐co‐polycaprolactone (PCL) tri‐block copolymer was synthesized and characterized. The developed biodegradable scaffold was further modified with β‐tricalcium phosphate (β‐TCP) bioceramic for bone tissue engineering applications. The developed biocomposite was characterized using H nuclear magnetic resonance and Fourier transform infrared spectroscopy. Moreover, the bioceramic particle size distribution and morphology were evaluated using Brunauer–Emmett–Teller method, X‐ray diffraction, and scanning electron microscopy. The mechanical properties and biodegradation of the scaffolds were also evaluated. Cytotoxicity and mineralization assays were performed to analyze the biocompatibility and bioactivity capacity of the developed biocomposite. The characterization data confirmed the development of a biodegradable and photo‐cross‐linkable PCL‐based biocomposite reinforced with β‐TCP bioceramic. In vitro analyses demonstrated the biocompatibility and mineralization potential of the synthesized bioceramic. Altogether, the results of the present study suggest that the photo‐cross‐linkable PCL‐PPF‐PCL tri‐block copolymer reinforced with β‐TCP is a promising biocomposite for bone tissue engineering applications. According to the results, this newly synthesized material has a proper chemical composition for further clinically‐relevant studies in tissue engineering. [ABSTRACT FROM AUTHOR]

Nanoscale co-delivery systems are advanced examples of combination therapies that can provide better therapeutic performance. Here, we tried to improve the solubility, bioavailability, synergistic, and potentiation properties of docetaxel (DTX) using co-loading of DTX and quercetin (Qu) into PCL-PEGPCL- based nanocarrier. To this end, PCL-PEG-PCL copolymer synthesized, then, DTX and DTX/Qu loaded into this nanocarrier, separately, by the nanoprecipitation-modified method. Physicochemical and biological properties of nanocarriers were assessed on human liver cancer (Hep-G2) and normal fibroblast cell lines, then, results were compared with free-DTX, free-Qu, and free-DTX/Qu groups. Based on the results, particles morphologically possessed a quasi-spherical shape with an average size of less than 200nm. Moreover, DTX/Qu-coloaded nanocarrier was led to further inhibition of Hep-G2 cells and lower inhibition of FNF cell viability, in a lower concentration (IC50: 29.35 μg/ml) than DTX-loaded nanocarrier (IC50: 36.73 μg/ml), free-DTX (IC50: 49.81 μg/ml), and free-DTX/Qu (IC50: 37.16 μg/ml). It could be due to the mixing of Qu and DTX that leads to an increase in the potentiation of DTX. The results also showed the release mechanism of Qu and DTX can be respectively diffusion (Fickian model) and a combination of dissolution and copolymer degradation (non-Fickian model). This was led to the higher inhibition of Hep-G2 at lower concentration of drug and higher antioxidant activity of DTX/Qu-co-loaded nanocarrier than other groups, at lower inhibition of FNF cell growth. Accordingly, the synthesized nanocarriers showed a more impact on the inhibition of cancer cells compared to normal cells, due to the synergistic effect and the created potentiation. [ABSTRACT FROM AUTHOR]

Solution behavior of two commercially used polyether glycols with poly(oxyethylene) (PEO)-poly (oxypropylene) (PPO)-poly(oxyethylene) (PEO) triblock composition--Diol (linear) and Triol (star-like)--was studied, concerning the concentration and temperature effects until the cloud point (CP). 2-(2-butoxyetoxy) ethanol (DB) increased their miscibility with water. The structural study was performed with 25% DB in water, which produced isotropic solutions at room temperature at all polymer concentrations. Micelle's formation was only observed above 40% of polymer, when reversed micelles were formed. The solvent nuclei of the reversed micelles increased with increasing polymer concentrations, caused by dehydration of the PPO chains, then decreased at further higher concentrations, with completely dehydrated hydro-phobic chains. When CP is reached, the solvent nuclei are separated by large polymer domains, without phase separation. Neither ordered nor gel phase was formed, probably due to a combination of high miscibility and short hydrophobic segments. The study was performed by Small-Angle X-ray scattering (SAXS) and complemented by Fourier-transformed infrared spectroscopy (FTIR) and dynamic light scattering (DLS). The main contribution of this work is based on the fact that the knowledge of the solubility behavior of Diol and Triol, by changing the solvent or temperature, opens up new possibilities of their use to phase separation processes in industrial applications and delivery systems. Moreover, the elucidation of mechanisms of solubility allows for the design of novel polyether glycols with tailored solution behavior for efficient performance in its target use. All applications rely on their solution behavior and can be benefited from the present results. [ABSTRACT FROM AUTHOR]

A method of continuous methyl methacrylate polymerization in suspension using a cascade of full mixing reactors and full displacement columnar apparatuses is proposed. Dispersity of the system and process temperature greatly affect the particles settling dynamics. A mathematical model of polymerization kinetics is proposed for optimizing temperature conditions. Based on analysis of experimental data and theoretical premises an apparatus was developed for optimizing continuous suspension methyl methacrylate polymerization that produces homogeneous polymethyl methacrylate particles of the desired size. The proposed unit can be used to polymerize methyl methacrylate and get its copolymers and to polymerize monomers that form systems close in properties to systems based on methyl methacrylate. [ABSTRACT FROM AUTHOR]

Poly(2-chloroaniline-co-2-ethylaniline)-composite-Zn was synthesized by in situ chemical oxidative method using ammonium per sulphate as oxidant, HCl as dopant and linear alkyl benzene sulphonic acid (LABSA) as surfactant. The resulting copolymer composite was characterized by FTIR, and UV–Visible spectroscopic methods. The thermal stability was established using thermogravimetric analysis. The conduction mechanism was examined in terms of the dielectric constant and the electrical conductivity of 1.46 × 10–7 Scm−1 measured showed semiconducting nature. The oxidation/reduction potentials and electrochemical reaction of Li/copolymer cells were tested by cyclic voltammetric technique. Poly(2-chloroaniline-co-2-ethylaniline)-composite-Zn has been tested as anode in Li-ion batteries. The discharge and charge capacity of ~ 47 and ~ 14mAh/g at 1 to 5 cycles show good reversibility. This is a feasible value for using it as the positive electrode material in lithium ion secondary batteries. [ABSTRACT FROM AUTHOR]

A synthetic style for preparing a graphene oxide/poly(ethyleneglycol)-b-poly(2-hydroxyethyl methacrylate-g-lactide)2 nanocomposites (GO/PEG-b-poly(HEMA-g-LA)) is via reversible addition fragmentation chain transfer polymerization. The characterization of GO/PEG-b-poly(HEMA-g-LA)2 nanocomposites was confirmed by scanning electron microscopy, ultraviolet–visible (UV–Vis) spectroscopies and dynamic light scattering measurements. This system as a safe nanovehicle has been studied for cancer therapy. Adult male rats were randomly allocated into five groups. Rats received normal saline, doxorubicin (DOX 12 mg/kg), and GO/PEG-b-poly(HEMA-g-LA)2@DOX at 6, 12, or 24 mg/kg via intraperitoneal rout daily for 4 weeks. Finally, serum samples were obtained to determine serum biochemical parameters. After euthanasia, liver and kidney samples were preserved in formalin to perform histopathological analysis. [ABSTRACT FROM AUTHOR]

This manuscript includes some photophysical parameters and some optical properties such as absorption and emission spectra of the (E, E)-2,5-bis (3,4-dimethoxystyryl) pyrazine (BDP) by applying sol–gel and copolymer matrices. The BDP molecular structure is incorporated in sol–gel matrix and copolymer of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA). In case of sol–gel matrix, the BDP molecular structure has higher quantum yield in addition to photostability maxima. The laser behavior of this molecular structure containing sol–gel matrix is good senior compared to copolymer one via using diode laser (450 nm) as pumping laser of power 160 mW. Also, the fluorescence profile of the BDP molecular structure is sensitized via using cadmium sulfide (CdS) quantum dots (QDs) by applying sol–gel host. The optimized structure of the BDP molecule is obtained via applying B3LYP/6-31G(d) level of theory. The electronic absorption and emission spectra of the BDP molecular structure in ethanol solvent were calculated using time-dependent density functional theory (TDDFT) at CAM-B3LYP/6-31G + + (d, p) level. The obtained theoretical results were compared to experimental ones. [ABSTRACT FROM AUTHOR]

Poly-3-hydroxyalkanoic acids (PHAs) are bacterial storage polymers commonly used in bioplastic production. Halophilic bacteria are industrially interesting organisms, as their salinity tolerance and psychrophilic nature lowers sterility requirements and subsequent production costs. We investigated PHA synthesis in two bacterial strains, Halomonas sp. 363 and Paracoccus sp. 392, isolated from Southern Ocean sea ice and elucidated the related PHA biopolymer accumulation and composition with various approaches, such as transcriptomics, microscopy, and chromatography. We show that both bacterial strains produce PHAs at 4°C when the availability of nitrogen and/or oxygen limited growth. The genome of Halomonas sp. 363 carries three phaC synthase genes and transcribes genes along three PHA pathways (I to III), whereas Paracoccus sp. 392 carries only one phaC gene and transcribes genes along one pathway (I). Thus, Halomonas sp. 363 has a versatile repertoire of phaC genes and pathways enabling production of both short- and medium-chain-length PHA products. [ABSTRACT FROM AUTHOR]

• The copolymer of P (PEGMA-co-BVIm-Br) with PVI and PEGMA monomer was prepared by polymerization (RAFT) method and the newly modified super-hydrophilic M2-M6 membrane through NIPS. • Structural parameters in the morphology and performance of M1-M6 modified and unmodified membranes were investigated. • The modified membrane has a high anti-fouling nature and cleanliness nature and temperature-sensitive. • The M6 membrane exhibits a super hydrophilic membrane with a Mean±SD contact angle of 33.8±1.55 and the Mean±SD oil rejection of 96.1±1.3% and an increase in water flux. The conventional Polyvinylidene Fluoride (PVDF) membrane was modified by polymerization Reversible addition−fragmentation chain-transfer (RAFT) with copolymer (PEGMA-co-BVIm-Br) on the upper bulk. This copolymer was obtained from the synthesis of (BVIm-Br) 3-butyl-1-vinyl-1-H-imidazole-3-ium bromide and the vinyl imidazole (VI) monomer N-vinyl imidazole (a hydrophilic monomer) and 1-bromobutane (C4H9Br). The analysis of such as ATR-FTIR, the magnetic resonance of H-NMR nuclei, zeta potential, Water Contact Angle (WCA), and Scanning Electron Microscopy (SEM) confirmed the presence of copolymer on the surface of the modified membrane. The bonding of this copolymer on the membrane surface reduced the WCA of the membrane water (from 89.5 ±1.96 to 33.8 ±1.55). The raw PVDF membrane (M1) and modified membrane (with total ratio-P(PEGMA-co-BVIm-Br) copolymer 2.5 % (M2), 5 % (M3), 10 % (M4), 20 % (M5), and 40% (M6) to (raw PVDF membrane) membrane showed appropriate hydrophilic nature and excellent separation of oil droplets from water/oil emulsions in the simulated effluent on the surface. This operation was performed for a comprehensive study on the determined parameters and by filtration with simulated petrochemical industry effluent (containing water/oil emulsion). Therefore, the recovery efficiencies of water flux, flow flux, oil recovery amount, as well as total fouling of M6 membrane were reported 96.14±0.99 and 428±2.6 L/ (m2 h), 96.1±1.3%, and 17.18±0.37%, respectively. This study aimed to prepare a copolymer-modified membrane that can show high performance in cleaning and resistance to various fouling, such as Rt, Rr, and Rir at the specified temperature, after long-term emulsion separation. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, a novel kind of PMMA copolymer, P(MMA‐co‐MAA‐co‐SPMA), with permanently antistatic, high toughness, and high transparent properties, was synthesized via radical copolymerization. Herein, we selected the appropriate compatibilizer α‐methacrylic acid (MAA) and release agent (lauryldiethanolamine) through the calculation of solubility parameters for industrial mass production. What is more, the polymer's molecular weight was increased by improving the polymer's synthesis process. The structure and properties of the obtained copolymer were characterized. With 0.6 wt% of the 3‐sulfopropyl methacrylate potassium salt (SPMA), the copolymer exhibits nearly unchanged transparency with neat PMMA, and its unnotched impact strength reaches 16 kJ/m2. The surface resistance of the copolymer could be reduced to 1010 Ω, which could be considered as antistatic materials. Finally, the antistatic mechanism was analyzed. The main reason is that the hydrophilic group absorbs water to form a conductive layer on the surface, and 3‐sulfopropyl methacrylate potassium salt (SPMA) is an ionic monomer that can form ion channels in water molecules, further accelerating the leakage of accumulated electrostatic charges and improving the antistatic properties of the copolymer. The method of selecting compatibilizers and release agents through solubility parameters provides more opportunities for the development of PMMA with excellent comprehensive performance. [ABSTRACT FROM AUTHOR]

This present research aims at developing an efficient and reusable base catalyst to improve the biodiesel production for the need of green chemistry and sustainable development. To achieve this, the copolymer, namely poly(allylglycidyl ether-divinylbenzene-glycidyl methacrylate) (poly(AGE-DVB-GMA)), was firstly incorporated in the Fe 3 O 4 nanoparticles forming magnetic Fe 3 O 4 -poly(AGE-DVB-GMA) composites, and then organic guanidine was bound on the magnetic matrices via covalent bonds with active epoxy groups. The characterization of the as-made magnetic copolymer support and solid base catalysts was performed by several techniques, and the results revealed that the guanidine base was successfully tethered on the magnetic copolymer support. This developed solid catalyst possessed large surface basicity of 2.45 mmol/g and highly magnetic responsiveness with saturation magnetization value of 18.13 emu/g, displaying good activity to the transesterification of soybean oil to biodiesel in a heterogeneous manner. Under the transesterification conditions of methanol/oil molar ratio of 20:1, catalyst dosage of 7 wt%, reaction temperature of 65 °C, reaction duration of 8 h, the biodiesel yield of 92.6% was attained over the guanidine-based solid catalyst. Moreover, the catalyst could be easily separated under an external magnetic field, and showed satisfactory catalytic activity even after four reuse cycles, thus posing considerable potential for the sustainable and clean production of biodiesel. [Display omitted] [ABSTRACT FROM AUTHOR]

Homo polymer of dodecyl acrylate (DDA) and its copolymers with citral at different percentage composition (w/w) were synthesized by free radical polymerization method. The characterization of all the polymers was carried out through FTIR, NMR and GPC (gel permeation chromatography) analysis. The performance of all the prepared polymers as viscosity index improver (VII), pour point depressant (PPD) and antiwear (AW) additive in two different base oils (BO1 and BO2) were evaluated by standard ASTM methods. The results showed that all the polymers are good as VII, AW and PPD additives. AW and PPD properties of copolymers are better compared to homopolymer. Out of the three additive properties, PPD properties of copolymer (P‐2) was remarkably improved upto −26 °C for at 1 % (w/w) in base oil compared to homopolymer of dodecyl acrylate (−18 °C at 1 % w/w) as confirmed by photo micrographic analysis. The thermal stability of the polymers was determined by thermo gravimetric analysis (TGA). The stability against thermal degradation increases with increasing citral content in the acrylate backbone. Moreover the copolymers were eco‐friendly which was confirmed by biodegradability test (Disc Diffusion and Soil Burial Test method). [ABSTRACT FROM AUTHOR]

A new series of polysiloxane glassy cholesteric liquid crystal copolymers with menthyl- and cholesteryl-based mesogenic units in the side chains, denoted as P-MtxChy (x, y expresses the molar ratio of monomers Mt and Ch in copolymeric synthesis, and x + y = 7.) were successfully synthesised by hydrosilylation reaction. The mesomorphic properties and phase behaviours were studied by differential scanning calorimetry (DSC), polarising optical microscopy (POM) and X-ray diffraction. Optical properties were investigated by the UV-VIS spectrum. Using the volume-excluding action of mesogenic units in side chains, we obtained glassy cholesteric liquid crystal copolymers. By varying molar ratio of Mt and Ch in copolymers, the helical pitch was adjusted into visible light region. With the increase of Mt, the maximum reflection wavelength off normal 8 ° shifted from 548 nm of P-Mt3Ch4 to 650 nm of P-Mt4Ch3 to 872 nm of P-Mt5Ch2, and the reflected colours changed from green to red. These well-oriented glassy films have shown good morphological stability below the glass-transition temperature (Tg) for more than a year. [ABSTRACT FROM AUTHOR]

In this paper, we present a simple and feasible drug self-assembled delivery system with pH responsiveness and targeting function for cancer therapy. The drug delivery system is composed of an anticancer drug and an amphiphilic random copolymer based on phenylboronic acid, galactose, and polyethylene glycol monomethyl ether acrylate molecules and achieved through reversible addition–fragmentation chain transfer polymerization. The micelles present targeting function by introducing galactose molecules and show pH sensitivity on the basis of the interactions between phenylboronic acid and galactose molecules. Particle size, transmission electron microscopy, and drug release assays show the pH-responsive behavior of micelles at pH 6.0. Cellular uptake assay demonstrates that micelles can internalize HepG2 cells via receptor-mediated interaction. In addition, the drug-loaded micelles can considerably inhibit cancer cell proliferation as indicated by in vivo antitumor assay. The synthesized micelles may facilitate the development of valid drug delivery systems for cancer therapy. [ABSTRACT FROM AUTHOR]

We prepared dual hydrophilic triblock copolypeptide vesicles that form both micron and nanometer scale vesicles in aqueous media. The incorporation of terminal homoarginine segments into methionine sulfoxide-based vesicles was found to significantly enhance their cellular uptake compared to a non-ionic control. We also demonstrated that diblock and triblock copolypeptides with similar hydrophobic domains were found to mix well and form vesicle populations with uniform compositions. Blending of amphiphiles in vesicle nanocarriers was found to impart these materials with many advantageous properties, including good cellular uptake while maintaining minimal toxicity, as well as biological responsiveness to promote vesicle disruption and release of encapsulated cargos.

Vinylsulfonic acid (VSA), acrylamide (AM) and N, N methylene bis acrylamide(MBA) were copolymerized by radical polymerization in the presence of gum ghatti (GG) and treated water hyacianth (WH) in water. Several composite copolymers were prepared by varying the i) AM: VSA molar ratios ii) wt% of GG and iii) wt% of treated WH based on a Box-Behnken Design(BBD) of a response surface methodology (RSM) model with three input variables and the batch adsorption capacity (mg/g) of 100 mg/L Cd (II) from water as response. The composite polymer was characterized by Fourier transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis(TGA), X- ray photo electron spectroscopy (XPS), compressive strength, pH reversibility, pH at point zero charge (pH PZC), Brunauer-Emmett-Teller (BET) surface area and scanning electron microscopy (SEM). The network parameters of the composites were determined. The copolymer composite prepared with AM: VSA of 5:1 containing 10 wt% GG and 4 wt% treated WH showed an optimum batch adsorption capacity of 399.15 mg/g Cd (II) from water containing 100 mg/L Cd (II). The same composite showed an adsorption capacity of 170.1 mg/g and a removal% of 31.5 at a feed concentration/feed flow rate/bed height of 150 mgL−1/30mLmin−1/30 mm in a fixed bed column. [ABSTRACT FROM AUTHOR]

Abstract Silica scales and deposits are amorphous solids that plague industrial water treatment systems that manage silica-laden waters. Among the various mitigation approaches, silica scale inhibition is the most practically viable option. In this paper we report the effect of two polymeric silica scale inhibitors, namely a neutral poly(1-vinylpyrrolidone) (PVP) homopolymer, and a cationic poly(1-vinylpyrrolidone- co -2-dimethylaminoethyl methacrylate) (PVPcoDMAM) copolymer. These function as silicic acid (soluble silica) stabilizers and retard its autocondensation process to form amorphous silica scale. The comparative study included several experimental variables, such as pH (5.4, 6.0 and 7.0), polymer dosage (40–140 ppm) and solution salinity, as well as physicochemical characterization of the formed silica precipitates. It was found that the pyrrolidone monomer endows silicic acid stabilization features to both polymers, due to the hydrogen bonding interactions between the C O moiety of the cyclic amide pyrrolidone moiety and the Si-OH groups of silicic acid. However, for PVPcoDMAM the presence of the dimethylaminoethyl methacrylate functionality (containing ammonium and ester moieties) substantially enhanced its inhibition performance. Its overall silicic acid stabilization ability was ascribed to an intrinsic synergistic effect exerted by the neutral pyrrolidone, the cationic amine and the ester moieties. [Display omitted] • The polymers PVP and PVPcoDMAM were evaluated as silica scale inhibitors. • The cationic PVPcoDMAM is a more efficient silica scale inhibitor than PVP. • The amine and ester moieties enhance the inhibitory activity of PVPcoDMAM. • Both pyrrolidone and DMAM moieties contribute in the enhancement. [ABSTRACT FROM AUTHOR]

Acrylic acid and vinylamine copolymers represent one of the simplest polyampholyte structures. The acid-base and solution properties of these copolymers are hardly studied, and there are no works devoted to the synthesis of a set of copolymers with different compositions. We have synthesized a set of acrylic acid and vinylamine copolymers containing from 21 to 95 mol% acrylic acid units. The copolymers show the hydrodynamic properties and solubility of typical polyampholytes. Potentiometric titration revealed unusual acid-base properties of the new copolymers. The addition of HCl to the copolymers in the form of sodium/potassium salt results in only partial protonation of carboxyl anions and amine groups, including the acidic range (pH 2.5). This abnormally high acidity of acrylic acid and vinylamine copolymers is probably due to the formation of strong intra- and intermolecular hydrogen or ionic bonds between partially protonated and protonated groups: ∼COO−+H 3 N∼, COOH∙∙∙:NH 2 ∼, ∼H 2 N:∙∙∙ +H 3 N∼. Poly(vinylamine) and copolymers are able to stabilize curcumin in aqueous medium, significantly increasing its concentration in the neutral pH range. Polymers with high content of amine groups prevent curcumin degradation, probably by converting it to a more stable anionic form. New copolymers are promising substances for the creation of nucleic acid carriers for gene therapy and genetic engineering. The copolymer containing 21 % acrylic acid is comparable to poly(vinylamine) in terms of interaction with oligonucleotides, but yields more homogeneous polyplexes without the impurity of positively charged and potentially toxic particles. [Display omitted] • Co(acrylic acid – vinylamine) containing 21–95 mol% acrylic acid units were obtained. • The copolymers showed abnormally high acidity due to intra-/intermolecular bonding. • The copolymers are promising substances as curcumin and nucleic acid carriers. [ABSTRACT FROM AUTHOR]

The development of high temperature proton exchange membranes (HT-PEMs) is crucial for the advancement of high temperature proton exchange membrane fuel cells (HT-PEMFCs). The conventional use of phosphoric acid (PA) doped polybenzimidazole (PBI) membranes in HT-PEMFCs is associated with challenges such as a demanding synthetic procedure and the need for carcinogenic monomer. Therefore, the quest for cost-effective and readily synthesizable HT-PEMs with satisfactory physicochemical properties and commendable fuel cell performance is of great importance. In this work, a series of pyridine-containing aromatic copolymers are synthesized using a straightforward Friedel-Crafts hydroxyalkylation reactions. Five different aryl derivates including biphenyl, m -terphenyl, dibenzo-18-crown-6, 9,9-dimethylfluorene, 1,2-diphenylethane are adopted as the comonomers along with p -terphenyl to copolymerize with 4-acetylpyridine. Thus, the effects of different backbone structures with rigid, flexible or bulky moieties on the resulting membrane properties is investigated systematically. The PA absorption capacity and conductivity of the copolymer membranes increases, attributed to the introduction of twisted, hydrophilic or bulky moieties in the copolymer structures. One of the membranes, the P(TP-co-DMF) membrane with 9,9-dimethylfluorene groups, achieves a good PA uptake of 194% when immersed in 85 wt% PA at 30 °C, which also exhibits a moderate tensile strength of 6.5 MPa and a high conductivity of 0.075 S cm−1 at 180 °C. Consequently, when tested in the H 2 –O 2 fuel cell under 180 °C and no backpressure condition, the P(TP-co-DMF)/194%PA membrane delivers a high peak power density of 947 mW cm−2. This performance highlights the significant potential of these copolymers for application in HT-PEMFCs. [Display omitted] • Series of poly(arylene pyridine) based copolymers are synthesized through one-step polymerization. • The introduced twisted, hydrophilic or bulky moieties in polymer backbones significantly affect the properties of HT-PEMs. • HT-PEMFC with dimethylfluorene containing P(TP-co-DMF)/194%PA exhibits a high peak power density of 947 mW cm−2 at 180 °C. [ABSTRACT FROM AUTHOR]

In the present work, development of carbon nanotube (CNT)/poly(conducting-co-insulating monomer) structures was proposed to improve the thermoelectric (TE) performance in CNT/polyaniline (PANI) composites. To check the validity of this idea, we prepared multiwalled carbon nanotube (MWNT)/poly(aniline- co -acrylonitrile) composites by in-situ inverted emulsion copolymerization, and applied secondary doping with camphorsulfonic acid in m-cresol medium prior to the investigation of TE properties. The samples were characterized by FT-IR, UV–Vis, 1H NMR, DSC, GPC, CHNS elemental analysis, intrinsic viscosity, SEM, XRD, electrical resistance, Seebeck coefficient, thickness, and Hall measurements. We report that nitrile groups were hydrolyzed during the polymerization reactions to provide a polymer structure exhibiting aniline, acrylamide, acrylic acid, and glutarimide groups. Further, the poly(aniline- co -acrylonitrile) that prepared in the present work were random copolymers. Importantly, we found that 30 % MWNT/70 % poly(90ANI- co -10AN) composite exhibited a 63 % higher power factor (PF) of 5.48 μW/mK2 (σ : 225 S/cm, S : 15.6 μV/K) at 35 °C than that of 30 % MWNT/70 % PANI, which exhibited a PF of about 3.37 μW/mK2 (σ : 238 S/cm, S : 11.9 μV/K). This was ascribed to the decrease of carrier concentration together with the increase of carrier mobility in the 30 % MWNT/70 % poly(90ANI- co -10AN) composite as compared to the 30 % MWNT/70 % PANI. Improved thermoelectric properties by copolymerization of conducting with insulating monomers on carbon nanotubes. [Display omitted] • Inverted emulsion copolymerzation was performed. • Random copolymers were prepared using aniline (ANI) and acrylonitrile (AN). • MWNT/poly(ANI- co -AN) composites were prepared in-situ. • Thermoelectric performance of MWNT/poly(ANI-co-AN) composites were studied. • Power factor of MWNT/poly(90ANI- co -10AN) was higher than that of MWNT/PANI. [ABSTRACT FROM AUTHOR]

Polycarboxylate superplasticizers have been synthesized as copolymers of acrylamide with polyethylene glycol metallyl ether (HPEG), acrylic acid, and 2-hydroxyethylacrylate, with a molecular weight of 25–33 kDa. The copolymers were characterized using GPC and NMR, revealing that during copolymerization, the copolymer includes up to 10 mol.% HPEG 3500 Da. Copolymers at a dosage of 0.12 wt% provide significant retention time of the concrete mix. When considering the same mole ratios of HPEG/(other monomers) in the initial mixture, copolymers containing the carboxylate and hydroxyethyl acrylate group are the most effective. In terms of concrete strength, the use of quaternary copolymers (AA/AM/HPEG/2-HEA) results in a slowdown in strength gain at the ages of 1–3 days, while the strength at the age of 28 days exceeds that of double (AM/HPEG) and triple (AA/AM/HPEG) copolymers. [Display omitted] • Copolymers based on methallyl esters were synthesized for use as plasticizers for concrete. • Quadruple acrylamide copolymers containing 2-hydroxyethyl acrylate units and 6.9 mol.% metallyl ether of polyethylene glycol have the best plasticizing ability and ensure longer workability retention of concrete. • Copolymers ensure the workability retention of concrete for 4 h and can be used as individual admixtures or as slump retention agents for concrete. [ABSTRACT FROM AUTHOR]

In recent years, the continuous advancement of supercritical carbon dioxide (SC-CO 2) in the field of oil and gas production has highlighted the increasingly undeniable challenges posed by low viscosity. Issues such as gravity override, viscous fingering, and poor sand-carrying capacity have become more prominent. The introduction of SC-CO 2 thickeners stands as a promising solution to address current challenges. Despite over fifty years of history in the design of supercritical carbon dioxide thickeners, there is still no effective SC-CO 2 thickener that can be widely applied in the field. Therefore, the future development of supercritical carbon dioxide thickeners remains a topic of significant research interest. This paper reviews the current status, thickening mechanisms, and detailed thickening results of supercritical carbon dioxide thickeners. Special emphasis is placed on the crucial role of thickeners in controlling the flow properties of SC-CO 2 , their practical applications, challenges, and future research directions. The exceptional thickening performance of a novel copolymer and surfactant system incorporating in-situ nanoparticles has been demonstrated. These options present promising choices in both direct and indirect thickeners for supercritical carbon dioxide applications. • The development history and current situation of supercritical carbon dioxide thickeners were systematically introduced. • Studied the thickening mechanism of supercritical carbon dioxide. • Investigated the on-site application of various supercritical carbon dioxide thickeners. • Outlook on the future development of thickeners. [ABSTRACT FROM AUTHOR]

The present study reports the synthesis of poly(vinyl alcohol)-g-acrylamide (PVA-g-AAm) copolymer by grafting in presence of benzoyl peroxide initiator via free radical polymerization. The crosslinking was done in-situ by the addition of glutaraldehyde. The membranes were prepared by solution casting and solvent evaporation technique. The different amounts of heteropolyacid i.e Phosphotungstic acid hydrate (H3PW12O40) (HPA) was incorporated into the PVA-g-AAm membranes. The membranes were sulfonated by soaking in the solvent bath. The prepared membranes were characterized by FTIR to confirm the formation of the copolymer. The surface morphology is studied using SEM. The water uptake test, contact angle measurement, and ion exchange capacity were conducted to measure the physical properties of the prepared hybrid membranes. The modified membranes showed good proton conductivity at 50 °C around 10−2 Scm−1 and lower H2 permeability as compared to standard Nafion 115 membrane. The membrane containing 10 wt. % HPA PVA-g-AAm sulfonated membranes performed better with 0.578 Scm−1 as compared to plain PVA-g-AAm sulfonated membrane which shows the conductivity 0.248 Scm−1 under fuel cell atmosphere. The obtained results suggested that the incorporation of HPA into the proton-conducting copolymers is a good candidate for elevated temperature operation of proton exchange membrane fuel cells. Application to operate fuel cells at elevated temperatures is now being investigated.

Advances in multi-electron transfer materials and architectured electrodes are two important strategies for innovations in electrochemicalenergy storage. The attainment of both by interfacial electrodeposition of freestanding PPy-PEDOT copolymer films was reported. The composition of the copolymer was verified by FTIR and XPS spectra.The dispersion and microstructure of PPy and PEDOT were studied by EDX mapping and SEM. The capacitive performances of the copolymer films were studied by electrochemical measurements. The results show the copolymer film is composed of PPy and PEDOT with homogeneous distribution in a certain proportion.The SEM images show the film exhibits heterogeneous microstructure and has an open porous 3D network microstructure. Electrochemical characterization shows that the copolymer film is an excellent supercapacitor electrode material with high specific capacitance, good power capability and cycle performance. The multi-electron transfer nature of the copolymer, the copolymerization synergistic effects and the unique microstructure are responsible for the improved charge-discharge performances.

The research features a comprehensive study aimed at increasing the technological compatibility of multilayer packaging materials. The paper describes a recycling technology with the prospect of returning the resulting secondary raw materials to the production cycle. The research included the following tasks: to conduct a comprehensive study of polyolefin mixtures modified by ethylene propylene copolymer; to study the effect of the copolymer on the rheological and physicomechanical properties of polymer compositions; to propose a technology for the recycling of secondary polyolefin mixtures. The research involved the following methods: the capillary viscometry method was used to determine the rheological properties of polymer compositions; the tensile test method was employed to define the physicomechanical properties of the compositions; the pycnometric method was used to assess the density of the mixtures. The study featured such polymers as polyethylene, polypropylene, and ethylene-propylene copolymer, which was chosen as a link between the polymers. The authors obtained polymer compositions in various ratios of polyethylene, polypropylene, and ethylene-propylene copolymer: 70:30:0; 68.5:28.5:3; 65:25:10; 30:70:0; 28.5: 68.5: 3; 25:65:10. The article describes the process of modifying polyolefin compositions based on polyethylene and polypropylene by ethylene-propylene copolymer on a single-screw extruder. The authors defined the rheological properties and the deformation-strength characteristics of the polymer mixtures. Repeated processing proved to lead to a decrease in the physicomechanical properties of polyolefin mixtures, with the exception of compositions based on polyethylene and polypropylene in the ratio of 30:70, where the breaking stress increased. The number of processing cycles increased the melt flow rate of the mixtures. The proposed technology is meant for producing multilayer packaging materials using packaging waste in the middle layer for contact with food.

Compatibilization of immiscible polymer blends is by far the most general and efficient strategy to convert multiphase polymer blends with poor miscibility into high performance polymer alloys. The concept and necessity of compatibilization of immiscible polymer blends were analyzed. Various compatibilization methods were introduced to improve the miscibility of polymer blends, including the addition of block or graft copolymers, reactive polymers, low molecular weight chemical compound and functionalized nanoparticles, etc. In addition, the development of compatibilization methods was reviewed and the effect of compatibilization on the phase morphology and final properties of the blends was discussed, such as mechanical properties, thermal properties, electrical properties, etc. Finally, it was proposed that nanoparticle compatibilization will become a popular method in the field of blend compatibilization. This method not only can increase the capacity, but also increase the mechanical strength and possibly bring new properties to the blend.

The aim of this study was to evaluate the persistence of alkaline hydrogels based on a common (N,N′-methylenebisacrylamide, BIS) and three recently published tetraallyl crosslinkers. Such hydrogels have been shown to be suitable materials for the rehabilitation of cementitious materials. Of the four crosslinkers under investigation, N,N,N′,N′-tetraallylpiperazinium dibromide decomposed quickly in 1 m KOH solution and was not considered further. BIS showed the first signs of a decomposition after several days, while tetraallylammonium bromide and N,N,N′,N′-tetraallyltrimethylene dipiperidine dibromide remained unaffected. In contrast to BIS, which suffers from low solubility in water, the two tetraallyl crosslinkers show unlimited miscibility with diallyldimethylammonium hydroxide solutions. For the study, gels with up to 50 wt % crosslinker were prepared. Of these, gels containing tetraallylammonium bromide always show the highest degrees of swelling, with a peak value of 397 g/g at a content of 2 wt %. Under accelerated ageing at 60 °C for 28 d, gels crosslinked with BIS ultimately turned liquid, while the storage modulus and the degree of swelling of the two tetraallyl-crosslinked gels remained unchanged. This indicates that alkaline gels can be suitable for long application periods, which are common for rehabilitation measures in the construction industry.

Investigations regarding alternative methods for producing polymeric materials with hydrophilic properties have increased considerably. In this context, polymeric biomaterials with hemocompatible surface properties have been successfully obtained by grafting hydrophilic monomers onto commercial polymer films by simultaneous irradiation processes. In this study, simultaneous irradiation and grafting were used to produce a copolymer PVC-co-DMAEMA-co-heparin with hemocompatible surface properties. Characterization by FTIR of the graft copolymer indicates that the increase in monomer grafting levels inhibits the bonding sites to heparin. FTIR-PAS analyses of the graft copolymers showed that the highest graft levels were obtained for the irradiated samples containing 45% of monomer. Heparin, however, could only be detected in the irradiated samples containing 30% of DMAEMA. The analysis of the micrographs, on the other hand, showed that increasing the monomer concentration enhances surface roughness of the graft copolymers. Roughness however decreased with heparin addition. It was possible to verify that an excess of surface roughness of the graft copolymers inhibits anticoagulant properties of heparin, triggering thrombus formation. Platelet adhesion, on its turn, was not significantly affected by the presence of heparin when PVC-co-DMAEMA and PVC-co-DMAEMA-co-heparin, obtained from the systems containing 45% of monomer, are compared. The addition of heparin in the systems containing 30% of DMAEMA resulted in fewer thrombogenic surfaces. [ABSTRACT FROM AUTHOR]

In this work, we present the study of the conjugated copolymers 2,7-divinylcabazole and benzo-bis-thiadiazole, by the DFT method using the base B3LYP/6-31G (d, p). To evaluate the properties of these systems, we performed structural optimization without geometric restriction. The NBO analysis was obtained by an energy calculation of the DFT-B3LYP method under the atomic base 6-31G (d, p) from the optimized geometries. Calculations of vibratory frequencies of all the structures studied show that they have minima (all frequencies are positive) on the TPES. In order to study the electronic and optical properties, we calculated the HOMO and LUMO energy levels as well as the band gap (Gap energy). The absorption wavelengths of each system were calculated by the TD-DFT method at the functional level WB97XD under the atomic base 6-31G (d, p). [ABSTRACT FROM AUTHOR]

There are several parameters that affect the mechanical properties of carpets such as yarn characteristic and carpet construction. Yarn material is one of the most important factors which determine the usage performance of carpets by consumers. This study investigated the mechanical behaviours of carpets produced from polypropylene (PP) bulked continuous filament (BCF) yarns with not only polypropylene homopolymer but also mixing with copolymer (coPP) or thermoplastic polyolefins (TPO). In this respect, nine carpet samples produced by different types of BCF yarns used as pile were examined. Experimental results indicated that mixing polypropylene homopolymer with copolymer or thermoplastic polyolefin resulted with improvement in thickness loss and resilience properties. In addition, thermoplastic polyolefin mixed samples exhibited higher performance compared to those of copolymer, in both dynamic and static loading. PP BCF yarn composition had considerable influences on compressibility behaviours of carpets, whereas there was no significant effect on tuft withdrawal force. [ABSTRACT FROM AUTHOR]

Cellulose, which comprises D-glucose and L-glucose (D,L-cellulose), was synthesized from D-glucose (1D) and L-glucose (1L) via cationic ring-opening polymerization. Specifically, the ring-opening copolymerization of 3-O-benzyl-2,6-di-O-pivaloyl-β-D-glucopyranoside (2D) and 3-O-benzyl-2,6-di-O-pivaloyl-β-D-glucopyranoside (2L), synthesized from compounds 1D and 1L, respectively, in a 1:1 ratio, afforded 3-O-benzyl-2,6-di-O-β-D,L-glucopyranan (3DL) with a degree of polymerization (DPn) of 28.5 (Mw/Mn = 1.90) in quantitative yield. The deprotection of compound 3DL and subsequent acetylation proceeded smoothly to afford acetylated compound 4DL with a DPn of 18.6 (Mw/Mn = 2.08). The specific rotation of acetylated compound 4DL was + 0.01°, suggesting that acetylated compound 4DL was optically inactive cellulose triacetate. Furthermore, before acetylation, compound 4DL was an optically inactive cellulose comprising an almost racemic mixture of D-glucose and L-glucose. Compound 4DL was an amorphous polymer. This is the first reported synthesis of optically inactive D,L-cellulose. [ABSTRACT FROM AUTHOR]