RADICALS OF DIPHENYLBUTADIYNES AND THEIR INTERACTIONS WITH DIPHENYLPICRYLHYDRAZYL - A SUGGESTION FOR THE NONTOPOCHEMICAL POLYMERIZATION MECHANISM OF DIACETYLENE

Electron Spin Resonance studies of diarylbutadiynes such as diphenylbu tadiyne and p,p'-butadiynylenedi-(methyl benzoate) have shown that the se compounds contain free radicals at room temperature and that the nu mber of radicals in the solid state increases with temperature. The co lor of diphenylpicrylhydrazyl (DPPH) disappears when these diacetylene s are added. indicating that the stable DPPH radicals react with the d iacetylenes. The results suggest a probable initiation mechanism of th e polymerization of the diacetylenes which do not undergo topochemical polymerization.