High temperature thermosets derived from benzocyclobutenecontaining main-chain oligomeric carbosilanes

摘要

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 ~(13)C 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(CH_3)_2. Chemical simulation results attributed the lower temperature to lower steric hindrance and greater activity. DSC and TGA analysis of the thermosets showed high T_g and thermostability, and good pyrolysis yield.