Structurally Realistic Modeling of Elastomers

Abstract

Abstract This review covers the methods by which elastomers have been microscopically modeled and simulated since the mid-1960s. Of particular importance was the rotational isomeric state (RIS) methods of the Flory school in the 60s. His group was the first to attempt to use such statistical mechanical methods to determine observables such as the characteristic ratio, Cn. The early success of Flory's efforts were expanded in the early 1970s by members of his group in what appears to be the first true attempt to use molecular mechanics optimization techniques to obtain RIS statistical weighting matrices. Following these two pioneering breakthroughs, molecular mechanics techniques were refined and extended. Not much later, it became possible to perform temporal molecular dynamics simulations on flexible molecular liquids. Simulations of elastomer systems lagged somewhat; both single chains and elastomer amorphous liquids were not studied until the beginning of this decade. With the improvement in molecular forcefields and computational horsepower, it has become possible to perform simulations on relatively large-scale polymer systems. We track these developments, which include equation-of-state simulations and the simulation of oxygen diffusion in elastomers.