INTRAMOLECULAR ASSOCIATION IN FLEXIBLE HARD CHAIN MOLECULES

Due to the flexibility of associating polymer and protein molecules, i ntramolecular association can have a significant affect on the thermod ynamic properties and structure of associating polymer and protein sol utions. The equilibrium state is determined by the minimization of the appropriate free energy with respect to intermolecular association be tween like and unlike species and intramolecular association. As a fir st step to understanding this competition between intramolecular and i ntermolecular hydrogen bonding, we have conducted a molecular simulati on study of flexible hard chain molecules that intramolecularly associ ate in the absence of intermolecular association. To explain the simul ation results, we have developed a new simple and accurate theory of i ntramolecular association. By considering the limit of total bonding, we have also developed an accurate equation of state for hard rings. T he theory is in good agreement with new molecular simulation results f or intramolecularly associating hard chains, rigid hard rings, and ben t triatomics.