Diffusion of stabilizers in polymers. IV. 2,4-dihydroxybenzophenone in plasticized poly(vinyl chloride)

Abstract

The diffusion of the radioactively labeled ultraviolet stabilizer 2,4-dihydroxybenzophenone in compression-molded sheets of plasticized poly(vinyl chloride) was studied over the temperature range of 30°C–75°C. No detectable diffusion occurred in the 0% and 10% plasticized poly(vinyl chloride) when the diffusion temperature was below the glass transition temperatures of the polymers. Diffusion coefficients have been measured for plasticizer concentrations of 20, 30, 40, and 50 wt%. In each case, the variation of the diffusion coefficient D with temperature T can be represented by an Arrhenius expression D = D0 exp(−E/RT). The linear relation log D0 = −7.1 + 0.20E/T was obtained as an empirical expression of the results.