Abstract The physicomechanical and rheological characteristics of epoxyphosphazene-modified binders based on an epoxy-resorcinol resin and isophorone diamine and diaminodiphenyl sulfone hardeners are investigated. It is shown that the introduction of epoxyphosphazene into the epoxy resin helps to maintain the technological characteristics of the binder at an acceptable level and to attain a 40% increase

Abstract The thermal and thermomechanical properties of polyurethanes based on isophorone diisocyanate and polyfurit crosslinked using various curing agents are studied by differential scanning calorimetry and dynamic mechanical analysis. Two transitions are observed on thermograms in the temperature range from –100 to +150°С. The first transition detected at a temperature below –60°С corresponds to

Abstract A series of polyurethanes, polyureas, and poly(urethane ureas) with flexible blocks based on α,ω-bis(hydroxyalkyl)polydimethylsiloxane and α,ω-bis(aminopropyl)polydimethylsiloxane with molecular weights (5.6 and 0.9) × 103, respectively, is synthesized to obtain artificial vessels by electrospinning. The structure and properties of the polymers are characterized by gel permeation chromatography

Abstract Here we report the synthesis and viscoelastic properties of smart hydrogels based on N-isopropylacrylamide, cationic (3-acrylamidopropyl)trimethylammonium chloride and nanoclay. Hydrogels were prepared by aqueous free radical polymerization. The effect of some salts, N,N '-methylenebisacrylamide, (3-acrylamidopropyl)trimethylammonium chloride and nanoclay content on the viscoelastic properties

Abstract Natural weathering was performed in a Saharan region to characterize its effect on low-density polyethylene (LDPE) films used for greenhouse coverings. The morphological changes, followed by differential scanning calorimetry (DSC), showed that the damages caused by the oxidation of tie molecules increased the lamellae thickness, its distribution and the crystallinity. Wide-angles X-ray diffraction

Abstract Using modified amino ethers of boric acid, porous polyurethanes are synthesized, the porous morphology of which is due to the peculiarities of the hyperbranched macromolecular architecture of amino ethers of boric acid. A change in the structure of amino ethers of boric acid by the introduction of terminal bulky substituents with hydroxyl groups contributes to a change in the size and pore

Abstract Oligomeric hydroxyaryloxycyclotriphosphazenes P3N3Cln(OC6H5)x(OC6H4OH)y are obtained by the polycondensation of phenoxychlorocyclotriphosphazenes with the general formula P3N3Cl(6 − x)(OC6H5)x (x = 3.1, 4.5) with an excess of resorcinol under homogeneous (pyridine) and heterogeneous (K2CO3) acceptance of HCl in a yield of 60–85%. Full substitution of the chlorine atoms in the specified oligomers

Abstract The factors affecting the methanolysis of polycarbonates catalyzed by sodium methylate are studied. The conversion rate increases with an increase in the basic properties of solvents; the rate of methanolysis depending on the amount of solvent (tetrahydrofuran) is described by an extreme dependence. Changes in sodium methylate concentration and temperature have a small effect on the methanolysis

Abstract The effect of conjugated dinitrones N,N-dimethylglyoxaldinitrone, N,N-di-tert-butylglyoxaldinitrone, and N,N-diphenylglyoxaldinitrone on the radical polymerization of styrene initiated by azobis(isobutyronitrile) is studied. It is found that, during the polymerization of styrene at temperatures below 90°C, chains terminate on the studied nitrones to generate high molecular weight nitroxide

Abstract Poly(N-(3-carboxyphenyl)maleimide-alt-styrene) with superior heat-resistance was synthesized by free radical copolymerization and its structure was confirmed by FTIR and NMR spectroscopy. To show the advantages in heat-resistance of the synthesized copolymers, the thermal properties of poly(N-phenylmaleimide-alt-styrene) and poly(N-phenylmaleimide-alt-maleic anhydride) with similar structures

Abstract PEG-based smart hydrogels have excellent properties and are widely used in the drug delivery, tissue engineering and other fields. In this article, a temperature responsive and pH sensitive dual responsive hydrogel which is suitable for water plugging and profile control in the Daqing oil field was prepared via graft copolymerization using polyethylene glycol (Mn = 600, 1000, and 2000) and

Abstract The polymerization of commercial strained cycloalkene, 5-ethylidene-2-norbornene, in the presence of Pd–N-heterocyclic carbene complexes (two of which are synthesized for the first time) containing phosphine or pyridine ligands is studied. Upon activation with borate Na+[B(3,5-(CF3)2C6H3)4)]–, the studied Pd complexes catalyze the polymerization of 5-ethylidene-2-norbornene according to the

Abstract Novel lanthanide thiolate complexes of [LLn(SCH2C6H5)]2(THF) (L2– = [Me2NCH2CH2CH2N{CH2-(3,5-tBu2-C6H2-2-O)}2]2–; Ln = Sm(1), Yb(2)) has been developed for controlled ring-opening polymerization of ε-caprolactone at 20~40°C.

Abstract In recent decades, the need for producing adsorbents with high absorption capacity and easy separation has led to preparation of magnetic absorbents. In this study, green synthesis of iron oxide/cellulose nanocomposite was used to remove metronidazole from aquatic solutions by application of aqueous extract of spent tea waste regarding its effective and magnetic separation capability. The

Abstract A thermal-responsive Y-shaped amphiphilic block copolymer, namely poly(N-isopropylacrylamide-block-[poly(ε-caprolactone)]2 (PNIPAAm-b-PCL2), was synthesized through the combination of atom transfer radical polymerization (ATRP) and ring-opening polymerization (ROP) techniques, and its potential as smart anti-cancer drug delivery system was investigated preliminary. The fabricated polymers

Abstract In this study, cross-linked microspheres formed by interpenetrating networks of carboxymethyl cellulose and polyacrylic acid were prepared via inverse-suspension polymerization. The resultant has high adsorption capacity for rare earth ions, can reach 313 mg/g for Ce3+ under the condition of pH 6 at normal temperature. Unique self-creep characteristic gives it a fast-speed adsorption performance

Abstract A phenyl-substituted terephthalamide β-nucleating agent, N,N'-diphenylterephthalamide (DPTH) was synthesized and characterized by Fourier transform infrared spectroscopy (FTIR) and 1H nuclear magnetic resonance (1H NMR). DPTH’s effect on the crystallization and melting behaviors in isotactic polypropylene (iPP) was investigated by differential scanning calorimetry (DSC), wide angle X-ray diffraction

Abstract In this study, a new modified polymer by grafting poly(N-vinylpyrrolidone) onto polyethersulfone was prepared. The polymerization was carried out in a homogenous phase by using N-methyl pyrrolidone as solvent. Crucial parameters affecting the graft copolymerization, such as monomer concentration and absorbed dose were studied. The existence of grafted chains was confirmed by FTIR spectroscopy

Abstract Graphene oxide modified with long flexible hydrocarbon chains attracts increasing interest in toughing and stabilizing polymer nanocomposites. Herein, graphene oxide bearing with two types of long alkyl chains, namely 2-octyldodecylamine (swallow tail) and dodecylamine (linear), were prepared and introduced into polylactide by a master batch melt blending process. Swallow-tailed graphene oxide

Abstract Epoxy-based porous monoliths are prepared by chemically induced phase separation. The roles played by N,N-dimethylformamide (DMF) in both curing and phase separation kinetics are studied in detail. It is found that the addition of DMF not only changes the speed of phase separation, but the way. Meanwhile, the occurrence of secondary phase separation is partly inhibited, which is in favor of

Abstract Methacrylate-containing silsesquioxane–siloxane oligomers with Mw = (2–20) × 103 determined by gel permeation chromatography (GPC) are synthesized by acidohydrolytic copolycondensation of γ‑methacryloxypropyltrimethoxysilane and diorganodialkoxysilanes. According to the data of 29Si NMR spectro-scopy, the molecules of these oligomers contain silsesquioxane units (RSiO1.5)n, where R is a γ-methacryloxypropyl

Abstract The hydrolysis of three hydroxypropyl methylcellulose samples with varying degrees of polymerization by aqueous solutions of trifluoromethanesulfonic acid with a concentration of 1, 2, 3, and 4% at a temperature of 80, 90, 100, and 110°C in a microwave reactor is studied. The completeness of hydrolysis is estimated by 13C NMR spectroscopy of the disappearance of the signal the acetal carbon

Abstract The gas permeability of hydrocarbons (CH4, C2H6, n-C4H10) through four polynorbornenes obtained by modification of the addition poly(5-vinyl-2-norbornene) is studied. Upon modification, both polar (oxirane and thioacetyl fragments) and nonpolar substituents (cyclopropyl and ethyl groups) are introduced into side substituents. The introduction of polar groups leads to a decrease in gas permeability

Abstract Some properties of the product of tetrazolylethyl cellulose ether alkylation are studied. A comparative analysis of a change in the properties of heterochain (tetrazolated cellulose) and carbochain [poly(5-vinyltetrazole)] polymers when ionic N–H unsubstituted tetrazole rings are replaced with N-methyl-substituted ones in their macromolecular structure is performed. It is shown that the structure

Abstract Using transmission electron microscopy and UV–Vis spectroscopy, the effect of the concentration of the silver oligostyrylmonocarboxylate precursor in the range of 0.3–3.2 wt % in the reaction with the ED-20 epoxy resin on the formation of silver nanoparticles at a temperature of 75°C is studied. At the initial carboxylate concentration ≤0.3 wt %, silver nanoparticles with oligostyrylmonocarboxylate

Abstract New high-temperature resistant poly(carboranylmethyldiorganosiloxane)s have been synthesized by the polycondensation of 1,7-bis-[hydroxy(dimethyl)silylmethyl]-m-carborane with bis-(dimethylamino)diorganosilanes. It has been shown that the replacement of dimethylsiloxane units in polymer chain by methylphenylsiloxane or diphenylsiloxane units leads to formation of amorphous polymers. The polymers

Abstract Interpolymer complexes based on chitosan and arabinogalactan with a different degree of sulfation (7.7–40.8%) stable for 30 days are synthesized. The resulting complexes are characterized by scanning electron microscopy, IR spectroscopy, dynamic light scattering, and ζ-potential electrophoretic measurements. The main mechanism of complex formation is considered in terms of the electrostatic

Abstract Features of the synthesis of n-butyl acrylate copolymers with acrylic acid in 1,4-dioxane by free radical reversible addition-fragmentation chain transfer (RAFT) polymerization mediated by symmetric trithiocarbonates are considered. It is shown that the living mechanism of polymerization is realized in the studied systems. The chemical nature of the RAFT agent dictates different chain microstructures

Abstract Poly(aniline-co-4-bromoaniline) nanocomposites were prepared via in situ polymerization in different molar ratio in the presence of Cu2+−monmorillonite. The X-ray diffraction confirmed that the basal space of Cu2+−montmorillonite increased after the organophilization. Poly(aniline-co-4-bromoaniline)/Cu2+−monmorillonite nanocomposites were prepared by intercalating of aniline and 4-bromoaniline

Abstract The conducting film material intended for research in the field of cell technology is obtained on the basis of two biocompatible polymers—aliphatic copolyamide and polypyrrole. The material consists of hybrid nanofibers having the core–shell structure. The film is formed by copolyamide microfibers that are obtained by electrospinning and coated with a polypyrrole nanolayer. Studies show that

Abstract Polypyrrole/titanium dioxide nanocomposites with different compositions (10, 20, and 30 wt % of TiO2 with respect to monomer) were synthesized via in situ miniemulsion polymerization. The FTIR analysis proved the successful synthesis of the aforementioned products. The quasi-spherical nanostructure was observed through SEM images. TEM analysis showed a core–shell structure in which TiO2 nanoparticles

Abstract A new method is developed for the production of composite fibers based on cellulose and vinyltriethoxysilane and formed from N-methylmorpholine-N-oxide solutions. Introduction of the organosilicon additive promotes the activation of cellulose pyrolysis processes, and its choice relies on the presence of a double bond in vinyltriethoxysilane, which can be opened when the temperature rises.

Abstract The polymerization of acrylonitrile under the action of the new initiating system 1.4-diazabicyclo[2.2.2]octane–ethylene oxide is studied. The polymerization initiated by this system is accompanied by the occurrence of intra- and intermolecular chain transfer to the polymer. It is found that cyclic ethers, such as ethylene oxide and tetrahydrofuran, facilitate the reaction of chain transfer

Abstract The copolymers of acrylonitrile and acrylic acid are synthesized for the first time by trithiocarbonate-mediated reversible addition-fragmentation chain transfer polymerization in DMSO at a content of comonomers in the reaction mixture of 40%. Various regimes of acrylic acid introduction into the reaction are tested. This makes it possible to synthesize copolymers with close average composition

Abstract Ultradisperse polytetrafluoroethylene is separated into fractions soluble and insoluble in supercritical carbon dioxide. The initial polymer and its soluble and insoluble fractions are impregnated with silver(I) (1,5-cyclooctadiene)-1,1,1,5,5,5-hexafluoroacetylacetonate in supercritical carbon dioxide solution for 6.6 h under thermodynamic conditions at 65°С and 8 MPa followed by reduction

Abstract Aromatic polyimides used in the anionic polymerization of ε-caprolactam as polyfunctional activators are considered effective reinforcing agents of polycaproamide formed in their presence. It is shown that the nature of polyimide, the rigidity of its macromolecules, makes the dominant contribution to the strength characteristics of copolymers. It is found that molecular composites containing

Abstract Three water-soluble salts of poly[(4.4'-oxydiphenylene)pyromellitamic acid] with different chemical structure are synthesized. The data on their stability over time, rheological properties of aqueous solutions, density, and surface tension necessary for electrospinning are presented. Using scanning electron and atomic force microscopy, the structural-morphological characteristics of the synthesized

Abstract A procedure for producing nanocomposites by bonding polystyrene to the terminal carboxyl group and quantum dots based on CdSe and ZnS has been developed. The terminal functional group has been introduced into the polymer by radical polymerization with reversible chain transfer using trithiocarbonate. The effect of the reaction conditions and structure of the reversible chain transfer agent

Abstract An ecological strategy is discussed in this study, concerning the synthesis of a novel family of soluble conjugated polymers obtained by the copolymerization of thiophene with para-cholorobenzaldehyde. The reaction proceeded under mild conditions using a catalyst of clay origin (Maghnite-H+). This catalyst was prepared by creating active sites in the form of hydronium ions between the layers

Abstract A series of polyesters containing a photosensitive benzylidene chromophore in the main chain were synthesized from 2,6-bis(4-hydroxybenzylidene)cyclohexanone with various aliphatic and aromatic diacid chlorides by interfacial polycondensation technique. The intrinsic viscosity of the synthesized homo and copolymers determined by Ubbelohde viscometer and found to be 0.13–0.18 dL/g. The molecular

Abstract Chitosan is naturally occurring, biodegradable, non-toxic, non-allergenic biopolysaccharide derived from chitin which turns viscous upon dissolution in mildly acidic medium. Artificially changed chitosan consolidating hydroxyl chromone was set up by responding 6-Hydroxy-4-oxo-4H-chromone-3-carb-aldehyde with chitosan; it was found to have high specific and chelating proficiency towards transition

Abstract Nano-silica was modified with triazine derivative and characterized using FTIR and TGA techniques. Then the hybrid nano-silica was blended with polypropylene and intumescent flame retardant to prepare a novel intumescent flame-retardant polypropylene. Nitrogen and phosphorus elemental mapping micrographs and SEM micrographs elucidated that the hybrid nano-silica could facilitate intumescent

Abstract A new type of cross-linked copolymer granule was synthesized via emulsion polymerization and was characterized by FTIR spectroscopy. The O-carboxymethyl-chitosan was used as emulsifier for the copolymerization of methyl methacrylate and diacetone acrylamide. The resulting copolymer latex showed good compatibility with natural rubber. Morphology and surface roughness of modified natural rubber

Abstract Delivery of retinal progenitor cells (RPCs) for restoring injured or diseased retinal tissue using biodegradable scaffolds is a promising treatment for retinal diseases. Blend of three polymers; poly(ε-caprolactone) (PCL), poly(glycerol sebacate) (PGS), and poly(1,8-octanediol-co-citrate) (POC) was used to prepare a nanofibrous scaffold for retinal tissue engineering via electrospinning process

Abstract In this study, a novel KGM-based superabsorbent polymer KGM-g-poly-(acrylic acid-co-acrylamide-co-N,N'-dimethyl-N-ethylmethacryloxylethylammoniumbromide) (KAAD) was prepared, which was obtained by the free radical grafting solution polymerization of acrylamide (AM), acrylic acid (AA) and N,N'-dimethyl-N-ethylethacryloxylethylammonium bromide (DMAEA-EB) onto konjac glucomannan (KGM) with of

Abstract This paper reports the investigation of copolymerization of acrylonitrile with methyl acrylate, dimethyl maleate, dimethyl fumarate and dimethyl itaconate via atom transfer radical polymerization mechanism using copper bromide as a catalyst in combination with tris(2-pyridylmethyl)amine as a ligand. The reactivity ratios of monomers were evaluated using the Finemann–Ross and Kelen–Tudos methods

Abstract The alternating current (ac) electrical characterization of plasma polymerized pyrrole (PPPy) thin films have been discussed in this article. A parallel plate capacitively coupled glow discharge reactor was used to deposit PPPy thin films. To study the ac electrical conduction in the thin film, the variation of ac conductivity and dielectric constant of different thicknesses were investigated

Abstract Sulfonated copolymers of 1,3,4-oxadiazole, diphenyl oxide, and 10,10-dioxophenoxathiine are obtained for use as polymer superabsorbents. The one-pot synthesis of the copolymers is carried out in an oleum medium, with the starting reagents being 4,4'-oxydibenzoic acid and hydrazine sulfate. As a result, the copolymers are obtained with the same proportion of the oxadiazole fragment in the chain