Silsesquioxanes bearing side-chain amines as photoinitiator for light-cured methacrylate monomers

SILVANA V ASMUSSEN; IGNACIO DELL' ERBA; WALTER F SCHROEDER; CLAUDIA I. VALLO

Praga

Conferencia; 7th ECNP International Conference on Nanostructured Polymers and Nanocomposites; 2012

European Centre for Nanostructured Polymers

Photopolymerization science has assumed in recent years an increasing relevance in many applications, ranging from the production of paper, coatings, in dentistry, imaging science and printing. This technology is based on the use of photoreactive systems suited to absorb a light radiation of the appropriate wavelength and to produce primary radical species able to convert a multifunctional monomer into a crosslinked network. Photopolymerization of resins upon irradiation with visible light is commonly photoinitiated by the pair camphorquinone (CQ)/amine. Low-molecular-weight amines have intrinsic disadvantages such as odour, toxicity, and migration in UV-curing technology. These complications may be avoided by the use of high molecular weight photoinitiators that reduce the tendency to migrate. In this regard, polyhedral oligomeric silsesquioxanes (SSQO) appear as an interesting approach to increase the size of the amine molecules. The present study was carried out in order to explore the possibility of using silsesquioxanes bearing pendant tertiary amine groups as coinitiator of CQ. The photopolymerization of methacrylate monomers using CQ in combination with amine functionalized polyhedral oligomeric silsesquioxanes (ASSQO) at loadings between 0 and 30 wt% was investigated.