B. Jambe et al., THERMAL-DEGRADATION OF POLY(METHYL-N-HEXYLSILYLENE), Journal of polymer science. Part A, Polymer chemistry, 33(8), 1995, pp. 1283-1292
Thermal degradation of poly(methyl-n-hexylsilane) in the solid state i
n absence of oxygen reveals formation of a cyclic pentamer between 150
and 250 degrees C. Polymer is gradually degraded to an intermediate m
olecular weight distribution. The weight average of this new distribut
ion is not only temperature-dependent, but is also a function of visco
sity of the polymer and nature of chain ends. As no insolubles or Si-H
groups are formed, the degradation mechanism is most likely a back-bi
ting mechanism induced by active chain ends such as silyl anions or Si
-Cl rather than a homolytic cleavage of the main chain. A concurrent i
ntramolecular rearrangement reaction is also proposed. Moreover, this
study proposes an explanation to the trimodal molecular weight distrib
ution obtained by the Wurtz coupling of dichlorosilanes with molten so
dium in refluxing toluene. (C) 1995 John Wiley and Sons, Inc.