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-, ethylα-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.

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.

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New copolymers have been synthesized by anionic or radical photopolymerization of ε-caprolactam or methyl methacrylate (MMA) in the presence of dissolved polyimides bearing hexafluoroisopropylidene, fluorene or other groups. Using diimides as models it was shown that the kinetics of anionic polymerization of ε-caprolactam depends on the nature of spacer between the imide cycles. The mechanical and tribological properties of copolymers, their water absorbance and the microstructure of copolymer films were studied. It was found that upon the selection of polyimide activator it was possible to gain the desirable control over the polymer properties, namely, the gel fraction content, phase composition, compression modulus, notched Izod impact strength, friction coefficient and temperature of frictional contact. The kinetics of radical polymerization of MMA in the presence of polyimide and model diimide has been studied by differential scanning photocalorimetry and infrared spectroscopy. From the results of the reaction kinetics and the study of polymer structures by Fourier transform infrared spectroscopy, nuclear magnetic resonance, size-exclusion chromatography and thermogravimetric analysis it has been established that radical photopolymerization of MMA in the presence of polyimide leads to the formation of copolymers owing to chain transfer reactions and/or chain termination by the relevant condensation polymer. It has been established that the imide cycles play a significant role in the formation of both copolymers with ε-caprolactam and MMA, respectively.

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