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A procedure was developed for reprocessing polytetrafluoroethylene waste with the aim of its reuse in production of polymer composite materials. Polytetrafluoroethylene waste was mechanically treated on a specially designed and fabricated installation. The grinding rate and parameters of the cyclone for separating the

The thermal oxidative degradation of a polymer composite material based on polytetrafluoroethylene and oxyfluoride glass of composition 18BaF2–31SiO2–19B2O3–24BaO–8TiO2 under dynamic conditions has been studied. It is noted that the decomposition process takes place in several stages. The gaseous products of thermal oxidative destruction of the composite material were studied by mass spectrometry. The results of thermogravimetry and differential scanning calorimetry showed the stabilizing effect of oxyfluoride glass on the stability of polytetrafluoroethylene at elevated temperatures.

The aim of this study was to obtain new water-soluble polyguanidines, assess their antimicrobial properties with respect to the test objects of Escherichia coli and Bacillus cereus and establish the hazard class regulated in the territory of the Russian Federation. Polymers obtained in high yields by the method of polycondensation in the melt of the corresponding monomers and characterized by the methods of IR spectroscopy and elemental analysis. Serial dilution–agar plate procedure was performed in order to estimate antibacterial effects. The biocidal properties of the samples were estimated by the percentage reduction of microorganisms (% reduction). To determine the acute toxicity, a toxicometric assessment and symptoms of intoxication upon oral administration of a single dose were carried out in laboratory animals. New water-soluble guanidine-containing polymers with a number average molecular weight of 660–1040 Da were obtained. Copolymers with a low degree of substitution (10–20%) exhibit high antimicrobial activity among N-phenyl-substituted samples. As a result of the substituent increase in the polymer chain, their activity in relation to the studied bacteria is linearly decreased to a level comparable to the test sample. In contrast to the N-octyl-substituted copolymers, gram-positive bacterium B. cereus is more susceptible to N-phenyl-substituted samples. Substances after intragastric injection belong to the fourth class of toxicity (LD50 > 300 ≤ 2000 mg/kg) according to the requirements of tabulation of toxicity classes regulated in the territory of the Russian Federation. The combination of low toxicity with a high level of antibacterial activity of new guanidine-containing polymers suggests the possibility of obtaining new effective disinfectants.

Polycondensation of equimolecular quantities of bis-imidoyl chlorides with bis-phenols in the environment of organic solvents synthesized imino-analogues of polyarylate – polyimidate. The received polymers are soluble in amide solvents, solvents of phenolic type and tetrachloroethane, and have significant interval between temperature of plastic deformation and thermal stability that presents a good possibility of their processing to products by modern industrial methods. The mechanical durability of the film materials of polyimidates is 65–90 MPa, obviously expressed dependence of the deformation-strength parameters on the value of the molecular weight of the polymer is observed. Despite the fact that polyimidates are of interest as intermediate polymer intermediates in the synthesis of polyaramides, they have their own complex of high thermal and deformation-strength characteristics, which makes them promising as adhesives, film materials, fibers and laminated plastics. One of the most important in practical terms properties of film materials based on polyimidates is their proton conductivity after doping in a solution of phosphoric acid, which allows the use of these polymers as membranes in the design of fuel cells of hydrogen energy.

A new method was suggested for preparing aromatic polyphenylquinazolones by thermal polyhet-erocyclization of polyamidines containing free carboxy groups. The structure of the polyphenylquinazolones obtained was confirmed by elemental analysis and IR spectroscopy. The polymers obtained are soluble in a wide range of organic solvents and resistant to thermal and thermal oxidative degradation; they exhibit high deformation and strength characteristics. Such properties make these polymers promising for processing into various items by traditional methods.

Aromatic polyamidines were synthesized by polycondensation of equimolecular amounts of bisimidoyl chlorides with diamines in organic solvents. The obtained polymers are dissolved with organic solvents (N, N'-dimethylacetamide, N-methyl-2-pyrrolidone, etc.), and characterized by a large interval between the temperature of plastic deformation and heat resistance, that is a good possibility of processing polyamidine products with new industrial methods.

Polynaphthoylene benzimidazole and polybenzimidazole were obtained via polycondensation of 2,3,7,8-tetraaminodibenzo-p-dioxin with aromatic di- and tetracarboxylic acids in polyphosphoric acid. From a solution of polynaphthoylene benzimidazole in methanesulfonic acid a heat-resistant fiber with high tensile strength was obtained. Aromatic polybenzimidazoles are promising materials for producing membranes of medium-temperature fuel cells.

The morphology, structure, phase composition, and properties of composite materials based on polytetrafluoroethylene and oxyfluoride glass–ceramic of the composition 18LiF–31SiO2–19B2O3–24BaO–8TiO2 were studied.

The 1-aminoanthraquinone glycidyl ester (GEAA) obtained by reaction of N-alkylation of 1-aminoanthraquinone with epichlorohydrin was used in the synthesis of a structurally colored epoxy resin by co-polycondensation with with diphenylolpropane and epichlorohydrin. Structurally colored epoxy resin is a viscous liquid with a molecular weight of 400–1000, colored orange and soluble in organic solvents. The optimal amount of GEAA (from 0.1 to 0.5% wt.) is established, which provides high color intensity (molar extinction coeffi cient 0.16–1.38·104).

Aromatic polybenzimidazoles are synthesized via cyclopolycondensation of bis(arylene)hydroxamic acids with 4,4′-diphenylmethane diisocyanate and the structure of polymers is confirmed by the data of elemental analysis, IR and PMR spectroscopy. The properties of the obtained polymers are comparable to the characteristics of aromatic polybenzimidazoles prepared via the conventional scheme on the basis of о-phenylenediamines and dicarboxylic acids.

The possibility of obtaining a polymer gel based on polyhexamethylene guanidine hydrochloride and polyvinyl alcohol under conditions of acid catalysis is considered. It was shown that the use of formaldehyde as a crosslinking agent leads to the formation of methylene bridges between the hydroxyl groups of polyvinyl alcohol and the amino groups of polyhexamethylene guanidine hydrochloride. The study of samples obtained by IR spectroscopy revealed the presence of corresponding signals of functional groups at 2780 cm-1 (isolated methylene group between nitrogen and oxygen atoms) and 1580 cm-1 (characteristic band of the guanidine group).

Some research directions of formulations and technology of development for polymeric antifrictional composites (solid lubrican Fts) with increased physicomechanical tribological properties are considered. These composites are based on polytetrafluoroethylene and semi-interpenetrating polymer network (SIPN) matrices and mixed organic–inorganic fillers. Comparative analysis of qualification of materials when tested in field conditions and express testing using laboratory equipment provide a reliable screening of the service life of the materials to evaluate the performance of machines and mechanisms operating under the climatic conditions of the Russian North and the Arctic.

A method for the synthesis of hydrogels of poly(hexamethyleneguanidine hydrochloride) that is based on the interaction of polymer amino end groups with aldehydes is proposed. With the use of physicochemical analysis, the structures of crosslinked polymers are determined, the sensitivity of hydrogels to changes in the pH of medium is considered, and a preliminary study of their application as stimulators of the reparative regeneration of a cutaneous covering is conducted.

The study aims to obtain polyhexamethylene guanidine hydrochloride hydrogel compositions with extracts of medicinal plants growing in the Baikal region (Bergenia crassifolia, Calendula officinalis, Tussilago farfara) to evaluate sorption activity and consider the subsequent use of the compositions as an external wound healing agent. It has been shown that hydrogel sorbs mainly caffeinequinic acids in various compositions. It has been made an assumption about a link of sorption process with formation of secondary amino groups’ complex in the hexahydrotriazine cycle, which is formed as a result of gelation of PHMGhch, and carboxyl groups of extract substances. It is planned to study the wound healing activity of compositions by modeling skin damage of laboratory animals in future researches.

The one-step interaction of 1H-benzotriazoles with maleimides in melt at elevated temperatures has resulted in benzotriazolylsuccinimides. According to spectroscopy data, benzotriazolylsuccinimides obtained contain both major (benzotriazol-1-yl)-succinimide residue and minor (benzotriazol-2-yl)-succinimide residue. An effect of substituents in the initial reagents on the fine splitting of carbon peaks in 13C NMR spectrums of benzotriazolylsuccinimides is discussed. The influence of structure of benzotriazolylsuccinimides on their crystallinity degree is also discussed.

Results obtained in a study of doping of the friction surface of polytetrafluoroethylene with polymerpolymeric mixtures based on aromatic polyheteroarylenes with a structure of a semi-interpenetrating network are analyzed. It is shown that polymer-polymeric mixtures composed on polybenzimidazoles and poly(amino imide) resin are structurally active with respect to polytetrafluoroethylene and substantially improve the tribological and stress-strain properties of composite materials based on this compound.

Copolymers based on aliphatic diamines of various methylene chain lengths and guanidine hydrochloride were prepared by polycondensation in the melt. Antibacterial activity of water-soluble copolymers based on guanidine against conditionally pathogenic microorganisms Escherichia coli and Bacillus cereus was evaluated using diffusion in agar. Arelationship was found between the ratio of the number of hydrophobic methylene groups to the number of ionized guanidines and the antibacterial activity of the copolymers. Several samples showed high antimicrobial activity as compared with polyhexamethyleneguanidine hydrochloride (PHMGHC), which is widely used as a medical disinfectant.

A new method for the synthesis of hydrogels based on polyhexamethylene guanidine hydrochloride was proposed. The use of formaldehyde as a cross linking agent for binding the terminal amino groups of the polymer chain to form a center branch thereon underlies the method.

New polyamidobenzimidazoles derived from sulfonated diamine were synthesized, and strong films based on them were prepared. The synthesized polymers were characterized by Fourier IR spectroscopy, thermogravimetric analysis, and dynamic mechanical analysis, and their proton conductivity was measured.

The dependence of Huggins constant kof dilute polyhexamethyleneguanidine hydrochloride solutions on the synthesis duration and monomer molar ratio is determined. It is established that a partially branched polymer is formed at even an equimolar ratio of the monomers, a result that is testified by the rise of k' after 7 h synthesis from 0.35 to 0.80 in the absence of a rise in the characteristic viscosity.

Composite proton-conducting membranes in the form of interpolymer films are prepared in an aqueous medium from sulfo-acid-modified poly(ethylene glycol vinyl glycidyl ether) and poly(vinyl alcohol). The initial poly(hydroxysulfo acid) is synthesized through the radical polymerization of ethylene glycol vinyl glycidyl ether followed by modification with sodium sulfite via epoxy groups and treatment with a cationite in the H form. The proton-conducting membranes feature improved thermal stability (200–250°C), a breaking strength of 1.0–8.9 MPa, elasticity (a relative elongation at break of 1.0–8.2%), chemical resistance, and specific proton conductivity attaining 10−1 S/cm after doping with orthophosphoric acid.

In order to eliminate the negative environmental impact of transport and mechanisms operating under high speeds and loads, high abrasion wear, composite materials for sealing devices, thrust bearings, Goodrich stern bearings have been developed by the interaction of nitrile butadiene rubber with novolac resin, cured with dinitrile. The physico-mechanical and tribotechnical data of laboratory and production tests of the developed composites are shown.

An effect from the introduction of the benzotriazolyl fragments into the structure of thermoreactive resins based on benzotriazols and molar excesses of hexamethylene-bismaleimide was revealed. A change of thermal characteristics and improving mechanical properties and adhesion of the cured thermally glue layers to the surfaces of metallic samples made of Steel-3 were found. Such a conclusion was made from the data of the thermal analyzes and mechanical testes, when compared the samples made of both ‘pure’ hexamethylene-bismaleimide and the ones containing benzotriazolyl fragments.

There were obtained water-soluble polyguanidines of various structures and molecular weights by polycondensation in the melt of aliphatic amines and guanidine hydrochloride in the presented report. There was assessed the toxicity of a number of polymeric compounds in the acute and chronic experiment on fish. In turn this allowed the visionof the link between the structure of the macromolecular chain and toxic action. There was established the average fatal concentration and the threshold level of the fatal effect, which does not exceed the range of 0.5-2.5 mg/l for different polymer structures. Taking into account the fact that such concentrations are destructive for many unicellular organisms, it is possible to predict their high efficiency in the fight against ectoparasites of fish.

The published data on the chemical and physical modifications of cellulose aimed at creation of a wide variety of new innovative materials for hi-tech and priority directions in the development of science and engineering are summarized. Investigations into the chemical modification of cellulose via nucleophilic substitution, regioselective insertion of functional groups, graft copolymerization, oxidation, and esterification are covered. The importance of studies dealing with the search for new solvents of cellulose aimed at extension of the potential inherent in its modification and processing and in the design of nanocellulose-based materials is emphasized. On the basis of analysis of the literature data, the potential for creation of new functional materials for biomedical investigations, medicine, and electronics is shown.

It is shown that the nondestructive ablation of polyheteroarylenes induced by submillimeter radiation of a free electron laser may be used to determine the molecular masses of polymers. The experimental procedure is described, and its results are compared with GPC data.

Poly(N-phenyliminocarbonates) capable of converting into poly(N-phenylurethanes) via thermal treatment at 300°C for 9 h through the Chapman mechanism were prepared via the polycondensation of bisphenols with plenyliminophosgene. The resulting polymers are soluble in chlorinated hydrocarbons and amide solvents. The polymers are characteristic by glass-transition and 10%-weight-loss temperatures during heating in air of 165–210 and 455–490°C, respectively.

Dehydrocyclization of polyamidines into polybenzimidazoles under the action of various oxidants was studied. The strength and proton conductivity of membranes based on a blend of the polybenzimidazole obtained with poly(amino imide) resin were determined.

A new kind of crosslinking oligobenzotriazolylimides with terminal maleimide groups has been synthesized via an interaction of an excess of bismaleimides with 5,5′-bisbenzotriazoles in melt. Conditions of obtaining these oligomers were optimized via the syntheses of model compounds. Oligomers, according to dynamic thermogravimetric analysis (DTGA), fuse at 135–160°C, crosslink at 175–250°C, and possess the high thermal stability in air up to 410°C. Using these oligomers as thermosetting binders or crosslinking agents, tough laminate plastics reinforced by a glass-fiber cloth as well as crosslinked films on base of a linear polybenzimidazole (PBI) matrix were obtained. The plastics and the crosslinked films possess high mechanical characteristics. It has been proved that the crosslinked films on base of the PBI matrix are perspective precursors to design the phosphoric acid electrolyte membranes for the medium temperature fuel cells. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Acyclic polyimides are prepared for the first time through the interaction of imidoyl chlorides and dicarboxylic acids. This transformation passes through the formation of polycarboxyimidates, which, depending on the temperature of reaction, rearrange in situ via the Mumm-Hess mechanism or during subsequent heating to yield the target product. The polymers thus prepared show high solubility and thermal stability (380–450°C).

Interaction of imidoyl chlorides with various diamines, bisphenols, and dicarboxylic acids was studied.

The influence of the polybenzimidazole-to-polybismaleimide ratios and the chemical nature of sorbates on the thermodynamic characteristics of thermally structured blends of the polymers is studied. The optimum component ratio for the production of blends with good mechanical properties is found. The proton conductivity of the blends doped with phosphoric acid and acid zirconium phosphate is investigated.

The results of comparative tribotests of DU materials and developed netted sheet antifriction polytetrafluoroethylene-based materials during dry friction against a steel counterbody are discussed. It is shown that the netted sheet antifriction material is capable of long operation under the aforementioned conditions at up to 3 mps sliding velocities. IR spectroscopy and thermogravimetry of wear debris show a great amount of low-melting polytetrafluoroethylene destruction products that cause a decrease in friction temperature after the specimen run-in. The sheet material having a low wear rate, designed for operation in dry friction at high sliding velocities, can only be produced with a large volumetric share of polytetrafluoroethylene, which is the main condition for the formation of the antifriction layer. The Sharpy rule for sheet material friction at low wear rate is observed when the share of solid inclusions on the friction surface, the bronze frame in our case, is an order of magnitude lower that that of the softer and pliant matrix.

The paper presents results on the usage of ultrahigh-molecular-weight polyethylene for manufacture of antifrictional materials on a steel substrate. Hot molding regimes are determined for the production of polymeric components. The optimum degree of ultrahigh-molecular-weight polyethylene filling with graphite is determined (about 50 mass %) for the purpose of achieving perfect triboengineering parameters of sheet antifrictional materials during operation against a steel counterbody under boundary lubrication by water.

A possibility for the transformation of polyphenyl imidates, obtained by polycondensation of bisphenols with imidoyl chlorides of mono- and dicarboxylic acids, into N-phenyl-substituted aromatic polyamides and poly(N-benzoylamines) has been discovered. Such a rearrangement resulted from heating at 260–340 °C for 13–17 h, whereas in diphenyl ether solution at 240 °C for 10–14 h. The polymers synthesized are soluble in organic solvents and possess high stability against thermooxidative destruction.