FREE-RADICAL CROSS-LINKING EQUILIBRIUM COPOLYMERIZATIONS OF BENZYL METHACRYLATE WITH ETHYLENE GLYCOL DIMETHACRYLATE NEAR CEILING TEMPERATURES

摘要

The polymerization of benzyl methacrylate (BzMA) as a typical α -substituted vinyl monomer was explored at [M] = 1 mol/L at different temperatures. The equilibrium polymerization behavior was clearly observed at 150 ℃ . Then, the addition effect of ethylene glycol dimethacrylate (EGDMA) on the equilibrium polymerization of BzMA was examined. The initial molecular weight of the resulting network polymer precursor (NPP) increased with an increase in EGDMA mol% but no gelation was observed even in the presence of 10 mol% EGDMA cross-linker. Finally, the correlation of the inhomogeneity of the network structure with the occurrence of intramolecular cross-linking is discussed on the basis of the decreasing tendency of the intrinsic viscosity ratio [η]_(NPP)/[ η ]_(Linear) with an increase in the molecular weight of NPP, that is, with the progress of cross-linking.