Z. Hrnjakmurgic et al., INFLUENCE OF THE NETWORK ON THE INTERACTION PARAMETER IN SYSTEM EPDM VULCANIZATE-SOLVENT, Journal of applied polymer science, 65(5), 1997, pp. 991-999
Swelling measurements in six organic solvents were carried out on samp
les of dicumyl peroxide crosslinked ethylene-propylene-diene (EPDM) ha
ving various crosslink densities. The Flory-Huggins interaction parame
ter chi was determined for EPDM vulcanizates 312 and 812 as well as th
eir mixture 312/812 using the Flory-Rehner equation. The results show
that the chi parameter for the crosslinked polymer is greater than for
the uncrosslinked one and is a linear function of the crosslink densi
ty. The swelling behavior of the networks were also interpreted by the
Flory-Erman theory using the structural factor F-4' to characterize t
he network and its behavior during the swelling. The obtained chi valu
es indicate that broadening of the molecular mass distribution, in the
Gaussian region of distribution, mixture 312/812, increases interacti
ons with solvents. (C) 1997 John Wiley & Sons, Inc.