Equilibrium ring concentrations and the statistical conformations of polymer chains

摘要

A rotational isomeric state (RIS) model for polymeric sulfur chains has been used to calculate the concentrations of cyclics S_x with x > 8 in liquid sulfur below the critical polymerization temperature. The cyclics S_(12), S_(18) and S_(20) were predicted to be present in the largest amounts in agreement with experiment. Other cyclics such as S_(11) and S_(13) were predicted to be absent from the melt and they are known to be physically present in only trace amounts. Variations of structural and statistical weight parameters in the RIS model are explored. The original model is shown to give the best agreement with all experimental information.