The Effects of Structure of POSS on the Properties of POSS/PMMA Hybrid Materials

Octa-vinyl polyhedral oligomeric silsesquioxane (V-POSS) and octa-(methacryloxy) propyl polyhedral oligomeric silsesquioxane (M-POSS) were incorporated into PMMA to prepare POSS/PMMA hybrid materials at molecular level via in situ polymerization. The resulting hybrid materials showed only swelling instead of solution in ethyl acetate, while pristine PMMA completely dissolved in ethyl acetate; moreover, the M-POSS/PMMA hybrid materials exhibited more excellent resistance to solvent stress cracking. An excellent transparency was observed for all hybrid materials. Incorporation of V-POSS and M-POSS significantly improved thermal properties of PMMA. The thermal decomposition temperature of hybrid materials was enhanced except a slightly compromised initial decomposition temperature. The hybrid materials prepared with 0.2-0.6 mol% M-POSS or V-POSS improved the reinforcing and toughening properties in comparison to pristine PMMA. Also, the incorporation of POSS decreased the dielectric constant and dielectric loss of the hybrid materials with more voids introduced into the composites no matter the structure of POSS. POLYM. ENG. SCI., 55:565-572, 2015. (c) 2014 Society of Plastics Engineers