OBSERVATION OF COUNTERPART RADICAL ON MAIN-CHAIN SCISSION IN PLASMA-IRRADIATED METHACRYLIC POLYMERS

We describe the extended study of plasma-induced radicals in two methacrylic polymers which were strictly dried at higher temperature and for a longer time than before. It has been shown that the present electron spin resonance (ESR) spectra of plasma-irradiated methacrylic polymers are appreciably different from those observed previously, and are characterized by the presence of many small peaks on the outer side of major peaks. Computer simulations disclosed that the difference is caused by the presence of a fifteen-line component spectrum (V) of a previously unobserved radical (5) which should be produced by the addition of hydrogen radical to the counterpart isobutene-like moiety of the terminating radical (1).