Photocrosslinking Polymerization of Methacrylate Modified Triethoxysilanes Polycondensates and Multifunctional Methacrylates

✍ Scribed by Juraj Pavlinec; Norbert Moszner

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 117 KB
• Volume: 288
• Category: Article
• ISSN: 1438-7492
• DOI: 10.1002/mame.200300066

✦ Synopsis

Abstract

Densely crosslinked polymer networks were prepared by fast, visible light‐induced polymerization at 20–22 °C. The two methacrylate functionalized triethoxysilanes polycondensates (MSiP) either alone, or in a mixture with methacrylate modified oxozirconium clusters, were polymerized separately and as comonomers to multimethacrylate monomers in a weight ratio of 1:0.9. Pure organic networks based on 1,6‐bis(2‐hydroxy‐3‐methacryloyloxyethoxycarbonylamino)‐2,2,4‐trimethylhexane (UDMA) were used for comparison in the same ratio to other comonomers. The networks based on organic bifunctional monomers showed high, around 85% conversion of double bonds. Nevertheless the non‐reacted monomer that migrates to the toluene amounts from 5.6 to 11.65 wt.‐%. Copolymerization of UDMA with tetrafunctional components resulted in networks with higher residual unsaturation up to 27.7%. This result points out the important role that functionality and the spacer structure between the monomer double bonds play in the extent of reaction. Based only on modified inorganic SiOSi nano‐structures the networks are characterized by nearly complete building up of MSiP in the network, extreme crosslinks density, and mostly less than 1 wt.‐% of soluble substances. However, residual unsaturations exceeded 22%. The advantage of copolymerization of MSiP with proper organic comonomers as potential solvent free matrices for dental composites was demonstrated by a network consisting of MSiP II and UDMA. The 13.7% of unreacted double bonds and 99.65 wt.‐% gel content approximated efforts to minimize residual unsaturation and maximize monomer conversion in cured networks.

Monomers used for the synthesis of the densely crosslinked polymer.

magnified imageMonomers used for the synthesis of the densely crosslinked polymer.