Modeling the amorphous phase of comb-like polymers

In this work, we apply a methodology recently developed by us to perform atomistic simulations of the amorphous phase of poly(alpha-octadecyl beta-aspartate) and poly(octadecyl acrylate). The simulation method, which is denoted SuSi/CB, combines the strength of an algorithm specially designed to generate atomistic models of dense amorphous polymers and the Configurational Bias Monte Carlo procedure. Modeling results reveal that poly(octadecyl acrylate) presents a tendency to adopt backbone helical conformations, while no trace of helicity was detected in the amorphous phase poly(alpha-octadecyl beta-aspartate). Regarding the side chain organization, the paraffinic pool formed by the octadecyl side chains is slightly greater for the poly(acrylate) than for the poly(beta-aspartate). According to these features, it can be concluded that the small chemical differences between the two investigated polymers are enough to provide some distinctive structural features. (c) 2006 Wiley Periodicals, Inc.