B. Gupta et al., CATION-EXCHANGE MEMBRANES BY PREIRRADATION GRAFTING OF STYRENE INTO FEP FILMS .1. INFLUENCE OF SYNTHESIS CONDITIONS, Journal of polymer science. Part A, Polymer chemistry, 32(10), 1994, pp. 1931-1938
Gamma radiation-induced grafting of styrene into FEP films was investi
gated by the preirradiation method. The degree of grafting was found t
o be strongly dependent on the synthesis conditions, such as radiation
dose, monomer concentration, crosslinker, temperature, and film thick
ness. The order of dependence of the rate of grafting on pre-irradiati
on dose and monomer concentration was found to be 0.64 and 1.90, respe
ctively. The activation energy for the grafting in the temperature ran
ge of 50-80-degrees-C was determined to be 27.9 kJ/mol. A negative fir
st-order dependence of grafting on film thickness was observed. The re
sults suggest that the initial grafting takes place at the film surfac
e and proceeds to the middle by progressive diffusion of monomer throu
gh the polystyrene grafted layers. (C) 1994 John Wiley & Sons, Inc.