Formation and reactions of paramagnetic species in irradiated micro heterogeneous copolymer systems with different electronic characteristics of components

The formation of paramagnetic species in the radiolysis of styrene-butadiene block copolymers and inter polymers of polystyrene and polytrichlorobutadiene was studied at 77 K using ESR spectroscopy. The results obtained reveal substantial non-additive effects in the radical yields. In the case of inter polymers, the observed yields are higher than the expected additive values (sensitization), whereas in the case of block copolymers the effect has the opposite sign (protection). The analysis of paramagnetic species demonstrates that the observed peculiarities result from interphase migration of electrons followed by their reactions with chemical traps (chlorinated groups or neutral radicals). It was concluded that the long-range reactions of electrons were controlled by electronic characteristics of micro phases.