A Monte Carlo simulation study of the mechanical and conformational properties of networks of helical polymers. Part II. The effect of temperature

In a recent article (Carri GA, Batman R, Varshney V, Dirama TE. Polymer 2005;46:3809 [17]) we presented a model for networks of helical polymers. In this article we generalize our results to include the effect of temperature and focus on the mechanical, conformational and thermo-elastic properties of the network. We find that the non-monotonic stress-strain behavior observed at constant temperature also appears in the stress-temperature behavior at constant strain. The origin of this behavior is traced to the induction and melting of helical beads by the application of large strains or reduction in temperature. Other conformational properties of the polymer strands are also discussed. We also study the network entropy and heat capacity, and find a non-monotonic dependence on temperature and strain. Our study shows that the entropy is controlled by the helical content whenever the latter is significant. Otherwise, the entropy corresponds to the one of a network made of random coils. In addition, the study of the heat capacity shows that strain shifts the helix-coil transition temperature significantly. Other results are also discussed.