メタクリル酸の放射線溶液重合

Abstract

In the polymerization of methacrylic acid in methanol solution, the rate of polymerization decreased as the polymerization temperature decreased in the range from -78 to +30 deg C. An apparent activation energy was calculated to be 3.6 kcal/mol. The rate of polymerization was proportional to 0.47 power of dose rate. Benzoquinone inhibited the polymerization. These results indicate that the polymerization proceeds by a free radical mechanism. The infrared spectrum and x-ray-diffraction diagram of polymethyl methacrylate prepared from esterification of polymethacrylic acid indicated that a syndyotactic polymer was obtained by low temperature polymerization. In the polymerization in methanol solution, the syndyotacticity increased as the polymerization temperature decreased, and (E/sub S/--E/sub I/), the difference of activation energy between syndyotactic and isotactic propagation, was calculated to be --0.5 kcal/mol. It was also found that the systemprecipitating polymers reduced the syndyotacticity. (from NSA of Japan)