Gelation in the reactions of dicarboxylic acid dichlorides with triols

Abstract

AbstractGelation in reactions of triols with dicarboxylic acid dichlorides was studied at various dilutions. Adipoyl dichloride and sebacoyl dichloride were reacted with three triols of different molecular weights. The pairs of reactants were chosen so that the reaction systems were characterised by a range of values of v, the number of bonds in the smallest ring structure which could form. In all cases gelation occurred at extents of reaction in excess of those predicted by the Flory‐Stockmayer theory. The excess reaction increased with dilution, and decreased with increase in v.The results are interpreted in terms of a combination of Frisch's and Kilb's theories of gelation, in which λ, the intramolecular branching parameter of Frisch, is given by the equation λ = const. v−3/2{(OH)0+(COCl)0}−1.