Highly heat-resistant branched silicon-containing arylacetylene resins with low curing temperature

Silicon-containing arylacetylene (PSA) resins exhibit excellent thermal stability. However, the high curing temperature limits their applications. Herein, we report that changing the topology of PSA resins from linear to branched effectively decreases their curing temperature with no deterioration of thermal stability. Two sets of resins based on silyleneethynylene-naphthalene-ethynylene (SNP) and silyleneethynylene-phenyl-ethynylene (SPN) repeat units were studied. It is found that the branched resins exhibit considerably lower thermal curing temperatures than their linear counterparts. The exothermic peaks for branched SNP (BSNP) and branched SPN (BSPN) are about 190 and 214 degrees C, respectively, which are 18 and 25 degrees C lower than those for their linear counterparts (i.e. PSNP and PSPN). Density functional theory was applied to theoretically explain the differences in the thermal curing temperature between the linear and branched resins. The lower curing temperature of the branched PSAs is attributed to the greater number of terminal alkyne groups per molecule which increases the reactivity of the curing reaction to transform into a crosslinked structure. In addition, T-d5 (the temperature at 5% mass loss) for BSNP and BSPN resins are 653 and 613 degrees C, respectively, which are comparable with those for their linear counterparts. (c) 2021 Society of Industrial Chemistry.

Automated summary

By changing the topology of PSA resins from linear to branched, the curing temperature can be effectively decreased without compromising thermal stability. Branched resins exhibit considerably lower curing temperatures compared to their linear counterparts, while maintaining comparable mass loss temperatures.