Studies on MMA-TBB Resin. II. The Effect of Dual Use of TBB and Other Initiators on Polymerization of PMMA/MMA Resin.

The effects of dual use of tributylborane (TBB) and benzoyl peroxide/ N,N-dimethyl-p-toluidine (BPO/DMPT) or camphorquinone/N,N-dimethyaminoethyl methacrylate (CQ/DMAEMA), as well as BPO/DMPT and CQ/DMAEMA for comparison purposes, on postpolymerization of PMMA/MMA resin were examined from the view point of long term changes of residual MMA and molecular weight. Each resin was polymerized and analyzed by high performance liquid chromatography and size exclusion chromatography. The effect of dual use of TBB and BPO/DMPT or CQ/DMAEMA on polymerization of PMMA/MMA resin was additive in nature and each initiator system worked rather independently without little interaction between the two. TBB was effective especially during the period of postpolymerization. On the other hand, BPO/DMPT used in combination with CQ/DMAEMA had a limited effect only during the initial period and little effect during postpolymerization. It was suggested that TBB was most suitable as a chemically accelerated initiator component for a dual cure system.