화학공학소재연구정보센터
Journal of Polymer Science Part A: Polymer Chemistry, Vol.41, No.1, 196-203, 2003
Polymerization of neat 2-ethylhexyl acrylate induced by a pulsed electron beam
The bulk polymerization of 2-ethylhexyl acrylate (2-EHA), induced by a pulsed electron beam, was investigated with pulse radiolysis, gravimetry, and Fourier transform infrared spectroscopy. The roles of the dose rate, pulse frequency, and added acrylic acid (AA) in the polymerization of 2-EHA were examined at ambient temperature. In the range of 12.6-71.2 Gy/pulse, the polymerization of 2-EHA was dose-rate-dependent: at the same total dose, a lower dose rate yielded a higher conversion. Also, a lower pulse rate gave a higher conversion at the same total dose. The addition of up to 10 wt % AA showed no increase in the conversion of 2-EHA at a low conversion (8 kGy), but at a higher conversion (16 kGy), a 20 wt % increase in the conversion of 2-EHA was observed. The estimated values (1.6 +/- 0.3) X 10(-3) (dM(3) s)(3/2) mol (- 1) s (- 1/2) for k(p)(G/2k(t))(1/2) and 2.6 +/- 0.8 dm(3) s J(-1) for 2k(t)G (where k(p) is the rate constant of propagation, k(t) is the rate constant of bimolecular termination, and G is the yield of free radicals) were obtained at relatively low conversions. The reaction rate constant of the addition of 2-EHA free radicals to the monomer was measured by pulse radiolysis and found to be 2.8 X 10(2) mol (- 1) dm(3) s (- 1).