Nanocomposites based on polymethylmethacrylate and silica were synthesized by means of bulk polymerization. The morphology of the obtained polymer composites was studied by scanning electron microscopy. It was established that silica influences the mechanical and tribological properties of nanocomposites.

The free-radical photopolymerization of (meth)acrylates in the presence of a polyheteroarylene dissolved in a monomer has been studied. The kinetics of the radical polymerization of these monomers mediated by polyheteroarylene and the corresponding model compound has been investigated by differential scanning photocalorimetry and IR spectroscopy. Based on the experimental data, it is inferred that copolymers form due to chain transfer and/or chain termination to polyheteroarylene macromolecules. With the use of ESR spectroscopy, new radicals generated upon the addition of model polyheteroarylene compound to the initial solutions are discovered and characterized. The mechanism of the formation of copolymers is advanced.

The three-dimensional free-radical copolymerization of MMA with diunsaturated comonomers of various natures in the absence and in the presence of 4 wt % aromatic polyimide (η inh = 0.38−1.02 dl/g) has been studied by isothermal calorimetry. It has been shown that, depending on the chemical nature of spacers separating double bonds of the comonomers, the kinetic curves of copolymerization may be divided into two groups, one of which is characterized by an almost complete absence of stationary portions. It has been demonstrated that the effects of the polyimide on the initial rate of copolymerization and on the parameters of the gel effect depend on the nature of diunsaturated comonomers and the molecular mass of the aromatic polyimide. The swelling of the polymer systems under study in toluene has been investigated, and the parameters of their network structure have been estimated. The irreversible flow deformation of the MMA copolymers with diunsaturated comonomers does not manifest itself up to a temperature corresponding to the onset of degradation of the copolymers. The incorporation of polyimide units improves the thermal stability of the copolymers.

Crosslinked copolymers capable of swelling in organic solvents were synthesized by the free-radical copolymerization of methyl methacrylate and 2-10 wt % allyl methacrylate in the presence of polyimide (4 wt %, eta(inh) = 0.38-1.02 dl/g), soluble in the starting reaction mixture, and without polyimide. Using isothermal calorimetry at 70degreesC, it was shown that, as the concentration of a crosslinking agent increases, conversions that correspond to the onset of autoacceleration and autoretardation and the intensity of the gel effect decrease. It was demonstrated that the addition of an aromatic polyimide to the system also influences the parameters of the gel effect in copolymerization and the homogeneity of the resulting polymer samples. Swelling of the polymer systems of interest in chloroform and toluene was studied, and the parameters of their network structure were determined. It was found that the thermal stability of PMMA was enhanced upon the addition of aromatic polyimide. When the amount of allyl methacrylate was reduced to 2 wt %, the compressive and flexural strength and moduli of the resulting polymers increased.

The free-radical polymerization of styrene and its copolymerization with MMA in the presence of polyheteroarylenes of various structures yielded new polymers that differed in molecular mass characteristics, solubility, and thermal and mechanical properties from the corresponding homopolymers. The properties of the as-synthesized polymers were compared with those of analogous polymer systems based on various (meth)acrylates and polyheteroarylenes. The free-radical polymerization of styrene in the presence of a model aromatic diimide and its copolymerization with MMA in the presence of an aromatic polyimide (PI) at various initiator concentrations was studied by calorimetry under isothermal conditions. Based on the experimental data obtained, a reaction scheme, including the formation of chemical bonds between PI macromolecules and styrene units in polystyrene (PS)-PMMA copolymers, was suggested.

Polymer systems were prepared through the free-radical Polymerization of methyl methacrylate in the presence of 4 wt% dissolved poly(arylates). The latter polymers were shown to affect the parameters of the gel effect. It was demonstrated that, as the molecular mass of poly(imide) dissolved in methyl acrylate grows, the conversion corresponding to the onset of autoacceleration and the rate of polymerization at all stages of the process decrease. The data on the free-radical polymerization of methyl methacrylate carried out in the presence of model compounds (diimide and diester) provide evidence that the reactions of chain transfer to the benzene nuclei of poly(heteroarylenes) are not the only path of copolymer formation.

The AIBN-initiated free-radical polymerization of methyl methacrylate carried out at 70 degreesC in the presence of 1-15 wt % dissolved poly(imide) was studied by calorimetry. it was shown that, upon the addition of poly(imide) (up to 10 wt %), the kinetic curves of polymerization demonstrate a shift in the onset of autoacceleration and autoretardation to lower conversions compared to the polymerization of pure methyl methacrylate. When the concentration of poly(imide) reaches 15 wt %, no gel effect is observed due to the existence of a strong diffusion control at all stages of the process. Based on the experimental data on polymerization conducted in the presence of a model bis(imide), as well as on the thermal initiation of the above process, it is inferred that poly(imide) macromolecules do not form additional polymerization sites but may take part in the reactions of chain transfer and (or) termination of growing poly(methyl methacrylate) macromolecules.

Free radical initiated polymerization of methyl methacrylate containing 1–15 wt% of dissolved polyimide is studied by a calorimetric method. It is shown that polyimide (up to 10 wt%) addition leads to a shifting of the initial autoacceleration and initial autoretardation conversions to lower conversion values than those for polymerization of plain methyl methacrylate. It is stated that polyimide macromolecules do not create additional initiation reaction centres, but may take part in chain transfer and/or termination reactions during methyl methacrylate polymerization. Besides polyimides some other aromatic polymers, namely polyesters, polyamides, poly(ether ether ketone)s and poly(phthalide)s, have been used in similar processes. The new copolymers obtained differ in properties (solubility, thermal resistance, etc) compared to corresponding polymer components.

The radical copolymerization of a series of fluoro(meth)acrylates and methyl methacrylate carried our in the presence of a polyimide yielded new polymeric systems which surpass the corresponding homopoly(meth)acrylates prepared under analogous conditions with respect to their molecular mass characteristics, It was shown that the solubility and the thermal and mechanical properties of the resulting copolymers are appreciably different from poly(meth)acrylates even when the amount of polyimide introduced into the polymerization system is small.

Radical chain (co)polymerization of a set of acrylates containing dissolved high performance polymers, namely fluoropolyimide, is performed. Based on the study of the structure and properties of the polymers (elemental composition, solubility, molecular weight parameters, etc) it is proposed that the copolymer formation reaction takes place due to a transfer chain reaction on the polyimide. The influence of acrylate (ethyl-, n-butyl-, methyl-α- fluoro-, ethyl-α-fluoro-, methyl-glycidyl-, butyl-, hexafluoro-iso-propylmethacrylate) and polyimide content on the properties of the copolymers obtained is studied. Clear and opaque, hard and elastic materials are obtained. These polymers differ in their characteristics from the relevant polyacrylates and their blends with polyimide prepared by the usual method of mixing. One-step catalytic polycondensation of diamines and tetracarboxylic acid dianhydrides in a solution of preformed polyimide is studied. It is shown that such a procedure influences the structure and properties of polyimides formed in situ.

New polymeric materials are obtained by the synthesis of acrylonitrile copolymers with butyl acrylate in the presence of a fluorinated polyimide dissolved in the blend of monomers. The thermal properties of copolymers and the formation of a surface in the multicomponent system are studied. The effect of composition of the polymer systems and the role of secondary structures formed under the thermofrictional action are considered.

Radical polymerization of acrylates containing dissolved fluorinated copolyimide was studied. The structure, thermal and strength properties, and solubility of the resulting polymeric systems were found to be different from those of the corresponding components and the polymer blends prepared by the conventional method.

The structure and properties of multicomponent copolymers were studied using an approach developed previously for the analysis of linear polymers. Equations were derived that describe the effect of composition on the physical characteristics of the copolymers, including the density, the glass transition temperature, the temperature of the onset of intense chemical degradation, index of refraction, and the stress-optical coefficient. These resulting equations were used to calculate the characteristics of five multicomponent copolymers. Copolymers containing up to five components were synthesized on the basis of MMA, butylmethacrylate, butylacrylate,nonylacrylate, 2-ethlylhexylacrylate, and heptylacrylate.

New mono- and bifunctional isopropenyl derivatives of o-carborane were synthesized according to the Wittig reaction, from the corresponding acetyl derivatives and methylenetriphenylphosphorane. The radical copolymerization with methyl methacrylate was investigated and thermal and thermomechanical characteristics of the obtained copolymers were studied. In copolymers prepared on the basis of a monofunctional carborane-containing monomer, the increase of glass transition temperature takes practically a linear course with increasing boron content. In crosslinked copolymers the presence of o-carborane fragments leads to the widening of the glass transition temperature range, predominantly at low temperatures, irrespective of the type of bifunctional monomer used.

The literature data on the polymerisation and copolymerisation of unsaturated derivatives of carbaboranes and silicon- and carbaborane-containing compounds as well as the physicochemical properties of the polymers obtained are surveyed. Special attention has been devoted to the synthesis of polymers with dicarbaundecaborate fragments and metallocarbaborane complexes based on them. The bibliography includes 118 references.

A method is proposed for determining the number of defects (branches and isolated loops) in densely crosslinked polymers, based on a comparison of experimental and calculated glass temperatures of the network, using the increment method in the calculation. The proposed procedure was applied to crosslinked copolymers of methyl methacrylate with carborane substituted exocyclic vinylsilane or various composition; a considerable number of defect structures was revealed.

The ability of unsaturated dicarbaundecaborate derivatives to radical copolymerization with vinyl monomers is established. The copolymers of 1-isopropenyl-(3)-1,2-dicarbaundecaborate salts with methyl methacrylate and acrylonitrile are synthesized and the optimum conditions of copolymerization are found. A new method for synthesizing polymeric metallocarborane complexes, catalysts of hydrogenation and isomerization of olefines and dienes, is developed.