Molecular Weight Distribution of Linear Chains in Step‐Growth Polymerization Under the Influence of Cyclization Reactions

Abstract

Abstract Two different equations are presented describing the frequency distribution ( f l ) of linear chains in step‐growth (SG) polymerizations. Two related equations for the weight distribution ( w l ) are formulated as well. All equations contain either an exponent α that represents the reaction rates (or probabilities) of chain growth versus cyclization reactions or they contain a cyclization factor β ′. Plots of f l and w l versus conversion or degree of polymerization are presented and discussed. Distribution curves of individual oligomers versus conversion and versus β ′ are described. Furthermore, the consequences for hyperbranched polymers resulting from polycondensations of ab n monomers are discussed. Analogous to Flory's theory all equations concern kinetically controlled SG polymerizations. magnified image