High temperature thermosets derived from benzocyclobutene-containing main-chain oligomeric carbosilanes

A series of benzocyclobutene-carbosilane thermosets derived from benzocyclobutene-containing oligomeric silylenephenylene (PBSEPs) were synthesized. DSC analysis results demonstrated that the reaction of PBSEPs presumably took place within the temperature range of 200-350 °C. FT-IR, 1H NMR and 13C NMR results demonstrated that this exothermic reaction was attributed to a [4 + 2] cycloaddition. DSC results further revealed that benzocylcobutene linked with silylene exhibited lower exothermic temperature compared with that linked with Si(CH3)2. Chemical simulation results attributed the lower temperature to lower steric hindrance and greater activity. DSC and TGA analysis of the thermosets showed high Tg and thermostability, and good pyrolysis yield.