High Pressure Influence on Processes of Free Radical Stabilization in Irradiated Polymethylmethacrylate Copolymers
Essential change of EPR spectrum shape and constants characterizing quantity of stabilized free radicals has been found out as well for — irradiation of serial polymethylmethacrylate (PMMA) and its copolymers in general conditions and in those of all-round compression by 10 GPa pressure.One can separate three ranges of doses differing in the value and character of this effect displaying. It is suggested that the peculiarities of radiation damage mechanism and pressure influence are connected with the size of local excitation ranges conditioned by energy release from co-operative recombination of radicals under radiation effect. The schemes of molecular transformations in the ranges of local excitation explaining the EPR spectra observed in PMMA copolymers for the different conditions and irradiation doses are proposed. The perspective of this methodic use to study some peculiarities of polymer and other material radiolysis and obtaining information on their microstructure is also discussed.