A novel functionalized stereoregular macrocyclic oligomeric silsesquioxane: synthesis and its fast self-crosslinking via thiol-ene radical addition polymerization

Abstract

In this contribution, we report the synthesis of a novel stereoregular macrocyclic oligomeric silsesquioxane (MOSS) macromer bearing vinyl and thiol groups. This MOSS macromer was synthesized using the coordinate of the metals (e.g., alkaline and copper) with vinylsiloxanolate as the starting compound. A three-step reaction route involving hydrosilylation and substitution was employed to obtain the targeted compound. The MOSS macromer as well as the intermediate compounds have been characterized by means of ¹H and ²⁹Si nuclear magnetic resonance (NMR) spectroscopy, MALDI-TOF mass spectroscopy and size excusive chromatography (SEC). This novel MOSS macromer can readily undergo the self-crosslinking via thiol-ene radical addition polymerization and a polysilsesquioxane elastomer was obtained and exhibited a glass transition temperature as low as −83 °C. It is expected that this novel MOSS macromer has potential applications for sealing, coating and biomedical materials owing to the simplicity in polymerization.