The dried rubber was cut into a square piece of known weight (about 0.2 g) and its cross-link density was then determined by immersing it in toluene (Fluka, commercial) (40 ml) to equilibrium-swell.
The driedrubber was cut into a square piece of known weight (about 0.2 g)and its cross-link density was then determined by immersing it intoluene (Fluka, commercial) (40 ml) to equilibrium-swell.