The role of pulse frequency and acrylic acid in the radiation-induced bulk polymerization of 2-ethylhexyl acrylate

Complete conversion of bulk polymerization of 2-ethylhexyl acrylate (2-EHA) monomer to high molecular weight polymer was achieved by pulsed electron beam irradiation. The role of pulse frequency, dose rate, oxygen, acrylic acid (AA) on the polymerization of 2-EHA was examined at room and 0 deg. C temperatures. It was found that in the range of 12.6-71.2 Gy/pulse, the polymerization of 2-EHA was dose-rate dependent: at the same total dose, lower dose rate yielded higher conversion. It was also found that lower pulse rate gave higher conversion at the same total dose. Addition of up to 10 wt% AA showed no increase in the conversion of 2-EHA at low conversion (8 kGy), but at higher conversion (16 kGy) 20 wt% increase of conversion of 2-EHA was observed. Estimated values (1.6±0.3)x10-3 (dm3 s)3/2 mol-1 s-1/2 for kp(G/2kt)1/2 and 2.6±0.8 dm3 s J-1 for 2ktG were obtained at relatively low conversion