Polymerization of dimethacrylate resins photoinitiated by the system camphorquinone-amine functionalized silsesquioxanes.

I. E. DELL'ERBA; S. V. ASMUSSEN; W. F. SCHROEDER; C. I. VALLO

Bogotá

Simposio; XIII Simposio Latinoamericano de Polímeros; 2012

Universidad Nacional de Colombia

Polyhedral oligomeric silsesquioxanes functionalized with amino groups (SSQO) were prepared by a two-stage synthesis procedure. First, a modified organotrimethoxysilane was synthesized by reacting 1 mole of N-(â-aminoethyl)-ã-aminopropyltrimethoxysilane with 3 mole of 1,2-epoxy-3-phenoxypropane and then the hydrolytic condensation of the modified silane catalyzed by formic acid. Methacrylate resins were activated for visible light polymerization by the addition of Camphorquinone (CQ) in combination with different mass fractions of SSQO. A clean and rapid photobleaching of the CQ/SSQO pair was observed upon irradiation of methacrylate resins. This makes the CQ/SSQO photoinitiator system very attractive for polymerization of thick sections. The progress of monomer conversion vs. irradiation time showed that the CQ/SSQO pair is an efficient photoinitiator system because a fast reaction and high conversion. Moreover, it was found that up to 22 wt% SSQO could be incorporated in the methacrylate resin without compromising the flexural or the compressive properties of the final material.