Assessment of the sliding link model of chain entanglement in polymer networks

The stress-strain relations derived from the sliding link model of chain entanglement proposed by Ball et al. (Polymer 1981, 22, 1010) are compared with experimental results. There is good agreement with Ogden's empirical treatment of several results obtained previously from general pure strain tests on rubber vulcanizates. New uniaxial data for random polyisoprene networks at various stages from the gel point indicate that a significant fraction of trapped entanglements does not behave as the sliding links of the model but gives the same contribution to the stress as the chemical cross-links.