The mechanism of initiation and kinetics of radiation induced polymerization of 1,6-hexanediol diacrylate (HDDA) was studied by pulse radiolysis with optical detection in cyclohexane solution and in pure HDDA at room temperature. In both cases a transient light absorption decreasing with the wavelength in the 270-400 nm wavelength range, but possessing a shoulder at 310 nm was observed. The spectrum did not change with time after the pulse. The absorption is due to α-carboxyalkyl radicals: the assignment was supported by the results obtained from the reaction of electrons with methyl 2-chloropropionate leading to dechlorination. The radicals produced from HDDA or from the chloro compound decayed in a second order process with rate parameters of 5 · 108 and of 4 · 109 mol-1 dm3 s-1 in cyclohexane. In the presence of oxygen the corresponding peroxy radicals decaying in very slow process (several milliseconds) were observed. The results are interrupted in terms of radical polymerization mechanism.
|Number of pages||5|
|Journal||International Journal of Radiation Applications and Instrumentation. Part|
|Publication status||Published - Jan 1992|