L. Wojnarovits et al., PROPAGATION AND SIZE-DEPENDENT CHAIN TERMINATION RATE PARAMETERS IN THE POLYMERIZATION OF ACRYLATES IN AQUEOUS-SOLUTION AS STUDIED BY PULSE-RADIOLYSIS, Pure and applied chemistry, A32(3), 1995, pp. 443-454
The radiation polymerizations of ethyl acrylate (EA) and hydroxyethyl
acrylate (HEA) monomers in aqueous solutions were studied. For pulse r
adiolytic experiments, optical detection was used to measure the conce
ntration of intermediates. The absorption spectra taken after a 2.6-mu
s pulse in N2O-saturated acidic solution of EA and HEA are shown to h
ave maxima. at 300 nm. It was proved by comparative measurements that
these maxima belong to alpha-carboxy alkyl radicals. At a low acrylate
concentration (below 1 mmol . dm(-3)) and a relatively high dose/puls
e value (above 30 yY), the decay of the transient signal occurs close
to second-order kinetics. Average values of the termination rate param
eters were calculated from aftereffect measurements. A computer progra
m based on numerical integration was applied in order to estimate the
individual rate parameters.