A STUDY OF SORPTION DESORPTION AND DIFFUSION OF N-ALKANES AND ALIPHATIC-HYDROCARBONS INTO POLYMERIC BLENDS OF ETHYLENE-PROPYLENE RANDOM COPOLYMER AND ISOTACTIC POLYPROPYLENE IN THE TEMPERATURE INTERVAL 25-70-DEGREES-C/

Sorption and diffusion of n-alkanes (C-5 to C-16), 2,2,4-trimethylpent ane, cyclohexane and 1,2,3,4-tetrahydronaphthalene into polymeric blen ds of ethylene-propylene random copolymer and isotactic polypropylene at 25, 40, 55, and 70 degrees C have been investigated using a sorptio n gravimetric method. The observed mass loss of the polymer decreased with an increase in the size of the penetrant molecule. Sorption- deso rption- resorption- redesorption (S-D-RS-RD) experiments were performe d to determine the true values of sorption and transport coefficients. A Fickian diffusion equation was used to calculate diffusion and perm eation coefficients. The first order kinetics of sorption was used to estimate the kinetic rate constants. Activation parameters for differe nt transport processes and molar mass between crosslinks were evaluate d and the results were used to discuss the polymer-solvent interaction s. The x-ray diffraction and scanning electron microscope analysis did not indicate any morphological changes of the samples.