2002 Volume 21 Issue 4 Pages 314-321
Polymerization characteristics of poly (methyl methacrylate) (PMMA)/(methyl methacrylate) (MMA) resin initiated by tributylborane (TBB) were compared with those by benzoyl peroxide (BPO)/N, N-dimethyl-p-toluidine and camphorquinone (CQ)/N, N-dimethylaminoethyl methacrylate from the aspects of temporal changes of residual MMA and molecular weight up to 4 weeks at 37°C. Residual MMA 30min after polymerization decreased from 8.15% for TBB resin, 8.39% for the BPO resin, and 9.19% for the CQ resin to 0.48%, 3.54%, and 6.79%, respectively, after 4 weeks. The molecular weights at 30min and 4 weeks after polymerization were 409×103 and 247×103 for TBB resin, 297×103 and 282×103 for the BPO resin, and 267×103 and 231×103 for the CQ resin, respectively. The present results revealed that the TBB-initiated polymerization had unique and different characteristics compared with those initiated by the other common initiators: (1) The decrease in residual MMA was fast, sustained for a long time and resulted in very low value; (2) high molecular weight PMMA was formed first and then decreased with time.