Thermodegradability of soluble polydiphenylsilane copolymers

In this work, fundamental aspects concerning thermal stability of soluble polydiphenylsilanes have been investigated. For this purpose oligomers with rigid diphenylsilylene connected through flexible methylhydrosilylene or methylphenylsilylene units have been synthesized. These polymers were submitted to thermo-scission and thermal analysis. Molecular models of the synthesized structures were used in dynamic simulations in order to find particular aspects linking the structure of the oligosilanes to their thermal stability. The possible paths of Si-Si bond breaking have been calculated based on the enthalpy of scission reactions and heats of the formation computed at the level of semi-empirical models. Both experiments and computations have been correlated to obtain insights of the silicon structure thermo-scission mechanism.