Relationship between dielectric behaviors and conversion of MMA during polymerization process

摘要

Poly(methyl methacrylate), which is prepared by polymerization of methyl methacrylate (MMA), is widely used in the fabrication of polymer optical fiber and devices. In this article, a dielectric measurement method was proposed to monitor the polymerization process. The measurement result is compared with that obtained by the traditional Abbe's refractometer method. By monitoring the dielectric behaviors of polymerization system, the correlation between dielectric properties of reacting bulk and conversion of MMA was established. The influence of reactive temperature, reactive time, conversion rate of prepolymerization, and oxygen environment was discussed. It was shown that the gel effect occurred at 2 h at the reactive temperature of 50°C when the conversion of prepolymer was about 24% with the absence of oxygen. The conversion rate obtained by Abbe's refractometer method was larger than that measured by dielectric method in the reaction metaphase.