Ethylene/propylene (E/P) and ethylene/propylene/5-ethylidene-2-norbornene (E/P/ENB) copolymers were obtained on rac-Et(2-MeInd)2ZrMe2 activated by a number of isobutylaluminium aryloxides: (2,6-tBu2PhO-)AliBu2 (1-DTBP) (2,6-tBu2,4-Me-PhO-)AliBu2 (1-BHT), (2,4,6-tBu2PhO-)AliBu2 (1-TTBP), (2,6-tBu2,4-Me-PhO-)2AliBu (2-BHT), (2,6-tBu2PhO-)2AliBu (2-DTBP), [(2-Me,6-tBu-C6H3O)AliBu2]2 (1-MTBP), [(2,6-Ph2-PhO)AliBu2]2 (1-DPP). This study shows how the structure of an activator influences catalytic activity and polymer properties, such as the copolymer composition, molecular weight characteristics, and thermophysical and mechanical properties. It has been shown that both the introduction of a bulky substituent in the para-position of the aryloxy group and the additional aryloxy group in the structure of an activator lead to a significant decrease in activity of the catalytic system in all studied copolymerization processes. Moreover, activation by bulkier aryloxides leads to lower levels of comonomer insertion and gives rise to higher molecular weight polymers. Broad or multiple endothermic peaks with different values of melting points are observed on the DSC curves of the copolymers obtained with different catalytic systems. The DSC of the thermally fractionated samples makes it possible to reveal the heterogeneity of the copolymer microstructure, which manifests itself in the presence of a set of lamellar crystallites of different thickness. The results also present the mechanical properties of the copolymers, such as the tensile strength (σ), elongation at break (ε), and engineering strain (EL). The synthesized E/P and E/P/ENB copolymers contain about 1–4 wt.% of the sterically hindered phenols obtained in situ as a residue of the hydrolyzed activators in the course of reaction quenching. This determines the increased thermooxidative stability of the copolymers.

Branched polystyrenes are synthesized by the radical copolymerization of styrene and divinylbenzene with reversible inhibition (in the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl) under deteriorating thermodynamic quality of the solvent. The resulting polymers are studied by size-exclusion chromatography combined with static light scattering, ozonolysis, NMR spectroscopy, and differential scanning calorimetry. The branched polymers synthesized by living radical polymerization are characterized by lower intrinsic viscosity values than their linear analogs. Kuhn–Mark–Houwink parameters for these polymers in a tetrahydrofuran solution ( а = 0.29) confirm the nonlinear architecture of macromolecules and a high content of pendant double bonds comparable in the order of magnitude with their theoretical content in the absence of the cyclization reaction indicate their branched structure. The glass transition temperature of the branched polystyrenes is 20–35°С lower than the glass transition temperature of the linear polystyrene.

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 the glass transition temperature of soft ester segments. A broad endothermic region (near 100°С) is related to the melting of crystal-like ordered structures formed by strong hydrogen bonding between hard segments. The relationship between the spectral-kinetic behavior of the photochromic compound introduced into the polymer matrix and the properties of the polyurethanes is investigated. The rate of photochemical transformations of the photochromic compound covalently bonded to the matrix may depend on the stage of the polymerization process at which it is introduced into the polymer.

Mixtures of a low density-polyethylene (LDPE) with a nitrile butadiene rubber (NBR), which is used as a coupling agent in polymer composites, were obtained by extrusion. A sol-gel analysis, together with the exclusion chromatography and IR spectroscopy, was employed to study the change in the sol content and molar mass distribution during the gamma irradiation of an NBR/LDPE mixture. A correlation is found between changes in the deformation and strength characteristics of LDPE/NBR mixtures after irradiation and the sol content.

Nanofibers of Al2O3 (commercial product Nafen (TM) which were modified by various silane coupling agents have been used to create hybrid materials based on copolymer of ethylene and propylene. Nanocomposites were obtained by in situ catalytic copolymerization on the rac-Et(2-MeInd)(2)ZrMe2/isobutylalumoxane system. Trialkoxysilanes with alkenyl (vinyl and octenyl) and alkyl (octyl) functional groups were used for modification. CP MAS NMR analysis (C-13 and Si-29) of all modified nanoparticles showed the absence of residual alkoxy groups and allowed to identify the type of formed siloxane groups (mainly T-2, T-3). EDX analysis of trimethoxyalkenylsilanes modified nanoparticles showed significant contribution of self-condensation reactions, otherwise, in the case of triethoxyoctylsilane condensation with surface Al-OH groups prevailed. It is found that octylsilane modification leads to remarkable improvement of mechanical properties (tensile strength - approx. 150%, elongation at break - approx. 50% with regard to neat copolymer) at low nanofiller dosage (0.63 wt %), significantly exceeding those for the materials with alkenylsilane treated nanofibers. In the case of octenylsilane even major decline in mechanical performance was observed. We believe that this behavior is determined by the distribution of nanofiller in the polymer matrix, which is markedly different for different surface treatments. TEM observations show that octylsilane modification leads to efficient dispersion of Nafen in polymer matrix, while the use of alkenylsilanes leads to partial or significant aggregation of Nafen particles.

The branched polymers containing different amounts of the highly branched fraction are synthesized by the radical copolymerization of styrene and divinylbenzene under conditions of the reversible inhibition by 2,2,6,6-tetramethylpiperidine-1-oxyl. The branched polystyrenes are studied by size-exclusion chromatography combined with static light scattering, viscometry, and pulsed-field gradient nuclear magnetic resonance. The branched polymers prepared by living radical polymerization (in the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl) feature reduced intrinsic viscosities and increased self-diffusion coefficients compared with their linear analogs. As the content of the highly branched fraction in the synthesized polymers grows, the Zimm contraction factor in toluene solution decreases to g′ = 0.13. The Kuhn-Mark-Houwink parameters for these polymers in toluene solution (a = 0.43) confirm the nonlinear architecture of macromolecules.

Nanofibers of Al2O3 (commercial product Nafen (TM)) with characteristic length of similar to 100 nm and diameter of similar to 10 nm were used to create new hybrid materials based on copolymer of ethylene and propylene. Nanocomposites were obtained by in situ catalytic copolymerization on the system rac-Et(2-MeInd)(2)ZrMe2/isobutylalumoxane. Formation of the nanocomposites with uniform distribution of Nafen nanoparticles in polymer matrix was confirmed by scanning and transmission electron microscopy. According to dynamic mechanical analysis data, introduction of the nanofiller in an amount of up to 3 wt % leads to an increase in glass transition temperature by 10 degrees C (E") and by 21 degrees C (tan delta). The nanocomposites exhibit improved physico-mechanical properties (tensile strength and elongation at break). It is shown that the nanofiller significantly improves resistance of the nanocomposite to the thermo-oxidative and thermal degradation. (C) 2016 Wiley Periodicals, Inc.

The influence of the curing conditions and dibutyl phthalate additions on the physicomechanical properties of cured polyepoxides based on ED-20 resin and 4,4'-diaminodiphenylmethane curing agent was examined. An increase in the curing temperature over 150°С does not noticeably influence the physicomechanical properties of the cured resin, and keeping of the reaction mixture at 180°С for 12 h leads to a considerable decrease in the glass transition temperature of the polymer. Addition of dibutyl phthalate in concentrations of up to 10 wt % decreases the glass transition teperature of the polymer by 44°C, but with increasing concentration of dibutyl phthalate the elastic modulus increases and the breaking strain slightly decreases. The dependence of the ultimate strength on the dibutyl phthalate concentration passes through a maximum at 3 wt % dibutyl phthalate.

Soluble branched chromophore-containing nonlinear optical (NLO) methacrylate copolymers were synthesized by two-stage procedure. At the first stage aniline-containing precursors were synthesized by radical copolymerization of ММА with N-methyl,N-phenylamino-2-hydroxypropyl methacrylate (АМА) in various ratios (90:10; 80:20; 70:30) with ethylene glycol dimethacrylate, EGDMA, being used as branching agent and 1-decanethiol, DT, as a chain-transfer agent. At the second stage these precursors were functionalized by 4-nitrobenzene-diazonium tetrafluoroborate giving the azofunctionalized methacrylate units, MAZ; and copolymers with NLO groups in the side chains were obtained. The synthesized copolymers were studied and some physical–chemical characteristics were determined. On the base of the synthesized copolymers thin films were spin-cast, their thickness being measured by AFM technique. The polymer films were corona-poled and the NLO characteristics were determined by second harmonic generation technique. The values of d33 are shown to depend noticeably on the chromophores concentration in the polymer; for various ratios of MMA:MAZ units (90:10; 80:20; 70:30) they are equal to 77pm/V, 45pm/V and 28pm/V, respectively. The values of NLO coefficients of branched chromophore-containing polymers are essentially higher than those of linear analogues obtained earlier in spite of an essentially lower concentration of chromophore groups.

Thermal properties and the deformational behavior of ternary alternating copolymers of carbon monoxide with ethylene and other olefins (propylene, 1-butene, styrene) with molecular masses of M n = 1000–35000 and molar fraction of the third comonomer in the polymer chain from 0.02 to 0.70 were investigated. Temperatures of melting and glass transition are significantly affected by the composition of the products. Varying the nature of the third comonomer or the content of its units in the polymer chain and the molecular masses of terpolymers makes it possible to obtain materials with Young’s moduli of 0.003–3.090 GPa and elongations at break of 5–2000%.

Изучены закономерности трехмерной радикальной полимеризации диметакрилата триэтиленгликоля в массе в присутствии 0–40 мас. % сополимеров на основе этилакрилата различного состава и некоторые структурно-физические свойства полученных сетчатых полимеров. Методом низкотемпературной адсорбции азота определены количественные характеристики их пористой структуры – значения удельной поверхности, общий объем пор. Показано, что в ходе золь-гель-анализа полимерные добавки удаляются из сетчатых полимеров с помощью бензола, а на их месте остаются поры c размером от 4 до 500 нм. Максимальное значение удельной поверхности составляет около 17 м2/г. Установлена зависимость величины удельной поверхности и общего объема пор от содержания полимерной добавки в исходной композиции.

New polymer gel electrolytes containing superbranched polymers were developed. The gel electrolyte containing 20 wt % superbranched polymer, 6 wt % methylmethacrylate, 4 wt % triethyleneglycol dimethacrylate, and 70 wt % 1 M propylene carbonate solution of LiClO4 was found to have a maximum conductivity of ∼9 × 10−4 S/cm at room temperature and an effective activation energy of conductivity of 18 kJ/mol. The physicochemical properties of the gel electrolyte were correlated with its composition using electrochemical impedance spectroscopy, thermomechanics, and differential scanning calorimetry. The glass-transition temperature of these electrolytes depended only on the liquid electrolyte content and decreased from −80 to −93°C when the concentration of 1 M LiClO4/PC increased from 60 to 80 wt %. As the content of the superbranched polymer increased from 0 to 20 wt % at positive temperatures, the modulus of elasticity decreased, while the conductivity increased. When the content of the superbranched polymer increased at the expense of the liquid electrolyte, the conductivity of the system decreased.

В работе изучены некоторые термические и деформационные свойства тройных чередующихся сополимеров монооксида углерода с этиленом и другими олефинами (пропилен, бутен-1, стирол) с молекулярной массой Mn = 1000–35 000 и мольной долей третьего сомономера в полимерной цепи от 0.02 до 0.70. Значительное влияние на температуру плавления и стеклования оказывает состав продуктов. Варьирование природы третьего сомономера или содержания звеньев третьего мономера в полимерной цепи, а также молекулярной массы терполимеров позволило получить материалы с модулем Юнга 0.003–3.090 ГПа и относительным удлинением при деформации 5–2000%.

The crosslinking radical polymerization of triethylene glycol dimethacrylate in bulk in the presence of 0–40 wt % ethyl acrylate-based copolymers of various compositions is studied, and some structuralphysical properties of the crosslinked polymers are investigated. The quantitative characteristics of their porous structures, such as the specific surface areas and the total pore volumes, are measured via the low-temperature adsorption of nitrogen. During sol-gel analysis, polymer additives are removed from network polymers with the use of benzene and pores with sizes from 4 to 500 nm occupy their places. The maximum specific surface area is approximately 17 m 2 /g. It is found that the specific surface area and total pore volume depend on the content of the polymer additive in the initial composition.