SORPTION, DESORPTION, DIFFUSION, AND PERMEATION OF ALIPHATIC ALKANES INTO SANTOPRENE THERMOPLASTIC RUBBER

The molecular transport characteristics of Santoprene rubber in the pr esence of n-alkanes, cyclohexane, 2,2,4-trimethylpentane, and 1,2,3,4- tetrahydronaphthalene at 25, 40, 55, and 70-degrees-C have been studie d using a sorption gravimetric technique. From the sorption and desorp tion studies, the diffusion coefficients have been calculated and used in the discussion of the transport results. It was observed that thes e data depend on the size of the penetrants. Furthermore, efforts were made to evaluate the permeation coefficients, molar mass between cros slinks, and the kinetic rate constants. These data showed a systematic dependence on the penetrant size. Activation parameters for the proce ss of diffusion and permeation have been calculated from the temperatu re dependence of the transport coefficients. (C) 1995 John Wiley & Son s, Inc.