Methacryloyl derivitized hyperbranched polyester. 1. Synthesis, characterization, and copolymerization

Three hyperbranched multi-methacrylates (H20-MMA, H30-MMA and H40-MMA) have been synthesized by reacting Boltorn dendritic polyols with methacrylic an hydride and methacryloyl chloride. Their structures were characterized by F T-IR and NMR (H-1 and C-13) and molecular weights were measured by GPC. The se multi-methacrylates (H-MMAs) mixed well with a variety of monomers such as acrylic acid (AA), methacrylic acid (MA), methyl methacrylate (MMA), 2-h ydroxy-ethyl methacrylate (HEMA), tri(ethylene glycol) dimethdimethacrylate (TEGDMA), and bisphenol A glycidyl dimethacrylate (BisGMA). The initial st udies on thermal polymerization activities of 10% of H-MMAs with AA, MA, an d MMA showed that they gave higher polymerization enthalpy than the corresp onding homopolymerization. The resulting materials showed one glass transit ion temperature, indicating a typical single-phase resin. The H-MMAs can ef fectively copolymerize with AA, MA, and MMA, with essentially no homopolyme rs produced, as indicated by acetone extraction studies. This indicated tha t the hyperbranched multi-methacrylates have the potential to be used as cr osslinking agents or modifiers with a number of monomers to produce new the rmosets.