Computational study of imperfect networks using a coarse-grained model.

The structural and mechanical properties of imperfect entangled polymer networks with various fractions of elastically active chains are studied using a generic coarse-grained model. Network topology is analyzed at various degrees of cross-linking and correlated with the mechanical response under uniaxial deformation at various strain rates. We found excellent agreement between results obtained from the structural analysis and from fitting to stress relaxation data. The relaxation tensile modulus at various engineering strains was also calculated as a function of the fraction of active strands. Results indicate that the mechanical and viscoelastic properties of entangled polymer networks are susceptible to variation in the network structure, where defects can affect the mechanical response especially at low strain rates and the relaxation behavior at long times.