Brackemann, H.; Buback, M.
Excimer laser-induced free-radical copolymerization of ethylene and acrylonitrile
Makromol. Chem. 1989, 190, 3073-3084.
 

The free-radical copolymerization of ethylene (E) and acrylonitrile (A) was studied up to 275°C and 2900 bar in continuously and in discontinuously operated devices. Polymerization is induced by KrF excimer laser light at 248 nm. In addition, results for copolymerizations with thermal and with chemical (oxygen) initiation are presented. The ethylene reactivity ratio, rE, is derived as a function of temperature. At 2450 bar, rE increases from 0,016 ± 0,003 at 150°C up to 0,055 ± 0,009 at 275°C. rE measured as a function of pressure, yields an activation volume of ΔV# (rE) = (-5,2 ± 3,5) cm3·mol-1. The kinetic information from the laser-induced experiments is used to describe the measured overall quantum yield, φ0, which is found to be a few thousand monomer molecules polymerized by one absorbed laser photon. φ0 decreases toward higher acrylonitrile content. The kinetic parameters are also used to predict overall and acrylonitrile conversion in continuous free-radical E/A copolymerizations with various chemical initiators.