Radiation-induced depolymerization of PMMA adsorbed on silochrome silochrome

The gamma-ray initiated depolymerization of the PMMA nanometer layer adsorb ed on silochrome was first studied by IR and UV spectroscopy. The kinetics of depolymerization wets investigated in the 120-180 degrees C range; the t otal activation energy of the process (at 40-50% conversion) was found to b e 31 +/- 4 kJ/mol. It was shown that the dependence of the depolymerization rate on the irradiation dose rate is close to linear. The radiation-chemic al yield of the monomer was determined; thus indicating the chain nature of the process. The possibilities that the reactions of repolymerization and chain transfer to monomer and polymer take place in the depolymerization pr ocess were analyzed. The approximate kinetic scheme of the depolymerization process is proposed, and the yield of the main chain scissions is estimate d.