Rigid polymer network models
نویسندگان
چکیده
2014 A model is presented for the elasticity of networks composed of rigid chains. The elastic modulus as a function of polymer volume fraction is determined for two cases : (a) the chains are rigidly crosslinked to each other i.e. the network may only deform by bending the chains (energetic network) and, (b) the chains are allowed to rotate freely about the crosslink points so that there is entropy associated with the crosslinks. A crossover concentration between the two behaviours 03A6c is defined. The reinforcement of a rigid network, by introducing a small concentration cp of straight rod-like elements of length P (much greater than the mesh size of the lattice) is found to increase the modulus by a factor, GP ~ cP P. Finally we discuss how rigid networks may swell, and « de-swell » if the solvent quality is changed and calculate a possible form of the swelling ratio, as a function of the length of the network chains. The system is found to be unstable for a swelling ratio greater than v2 eq = (5/4)3. J. Phys. France 51 (1990) 1113-1127 ler JUIN 1990, Classification Physics Abstracts 62.20D 81.40 03.40D
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