Radiation effects on branching polysilanes

Crosslinking and main chain scission reactions were investigated in the pre sent study for gamma -rays and ion beams in linear and branching polysilane s which have silicon branchings in the main chain at 5-32at.%. The crosslin king reactions become predominant for the irradiation with an increase in t he branching density. However, the efficiency of crosslinking reactions in linear and branching polysilanes are almost consistent in case of the irrad iation to ion beams. This is due to the differences in distribution of depo sited energy by gamma -rays and ion beams, and suggests that the size of th e chemical track is responsible for the gelation behavior of the polymers. The trace of formed gel was also concluded not to give the accurate G value s of crosslinking and main chain scission reactions in the polymers for hig h LET radiations such as ion beams. (C) 2001 Published by Elsevier Science Ltd.