INTERACTION OF CROSS-LINKED NATURAL-RUBBER WITH CHLORINATED HYDROCARBONS

The transport characteristics and the subsequent reduction in mechanic al strength of natural rubber vulcanizates have been investigated usin g chlorinated hydrocarbons as probe molecules. The transport process h as been examined by a sorption-desorption-resorption-redesorption tech nique. The mode of transport was found to change from the anomalous na ture to the regular Fickian trend after a sorption-desorption cycle. T he modulus of rubber samples decreased considerably under swollen cond itions. The marching trend of stress-strain curves vanished after solv ent saturation which has been explained on the basis of the absence of strain-induced crystallisation in swollen specimens. The modulus of s olvent-saturated samples was found to be a function of rubber-solvent interaction which has been explained in terms of the differences in th e contribution of physical entanglements to the total crosslink densit y. (C) 1998 Elsevier Science Ltd. All rights reserved.