MODEL NETWORKS - SYNTHESIS AND STRUCTURE

Model networks synthesized by endlinking processes are shown to be close to ideality and to exhibit few defects. Structure determinations carried out chiefly by neutron coherent scattering experiments on gels with deuterium labelled crosslinks demonstrated that the average distance between neighbor crosslinks d is a linear function of the cubic root of the swelling ratio Q. On the other hand, from the meansquare radius of gyration of the elastic chains it was established that no “supercoiling” can occur upon deswelling. To interpret the elasticity moduli measured on model networks we have tried to use De Gennes' treatment of semi‐dilute systems. Assuming that the swelling equilibrium is reached when the segment concentration is close to c* seems quite reasonable, since this leads to scaling laws with exponents very close to the experimental ones. © 1979 Hüthig & Wepf Verlag, Basel