ANALYSIS OF COMPOSITION AND STRUCTURE OF HARD AUTOPOLYMERIZING RELINERESINS

The authors investigated the composition and structure of six hard aut o-polymerizing reline resins. The chemical compositions, glass transit ion temperatures, molecular weights and particle size distributions of the powders, and the chemical compositions of the liquids were examin ed. The powder compositions were classified into three groups. The fir st group contained poly(methyl methacrylate). The second contained pol y(ethyl methacrylate) and poly(methyl methacrylate/ethyl methacrylate) and the third contained poly(ethyl methacrylate). The average molecul ar weights of these powders was about 2x10(5). The indexes of molecula r weight dispersion suggested that all powders contained polymers that had a narrow molecular weight distribution. The particle size distrib ution of these powders was classified into two groups. The first group was mainly in the range of 50-100 mu m and the second mainly between 20 and 50 mu m The composition of the liquids was classified into thre e groups. The first group contained a monofunctional methacrylate mono mer. The second contained a monofunctional methacrylate monomer and a plasticizer and the third contained monofunctional methacrylate monome rs and crosslinking agents. The results of this experiment showed the differences in composition among the products. This will be useful for examining the relationship between the composition and mechanical pro perties of hard autopolymerizing reline resins.