| Abstract: | Thermal behaviors of a few kinds of poly(fluoroalkyl methacrylate) prepared by γ-or UV-ray polymerization were investigated by using thermogravimetric measurements with the intermittent analysis of the gaseous products. The degradation of fluoroalkyl methacrylate polymers, monomeric units of which were CH2=C(CH3)COOCH2(CF2CF2)nH, n = 1, 2, and 3, proceeded according to the depolymerization mechanism reproducing the pristine monomer exclusively, but the thermogram in inert atmosphere showed the features of a two-step reaction. Two species of polymer differing in the heat stability were supposed to exist in the polymeric substance produced by γ- or UV-ray irradiation, and the fraction of polymer having lower heat stability increased with the increasing length of the fluoroalkyl ester group. In air, however, the thermogram of poly(fluoroalkyl methacrylate) showed no such a stepwise weight decrease as was observed in inert atomsphere with the elevating temperature, and the temperatures at which the depolymerization was introduced shifted to a much higher region. The results were ascribed to the reaction of initiating polymer radicals produced on polymer having lower stability with oxygen to form hydroperoxide, which once stabilized the polymer radicals and obstructed the initiaition of the unzipping reaction till higher temperature. |
