Synthesis of plasticizing polyesters of dimer acid and propane–diol

The polyesterification of dimer acid with propane–diol under different experimental conditions has been studied to obtain the optimum conditions for synthesizing the poly(propane–diol) dimerate plasticizers. The effect of varying molar ratio, temperature, and catalyst concentration on the course of the reaction, acid number, intrinsic viscosity, and molecular weight of the resultant polyester has been investigated. p‐Toluene sulfonic acid (PTSA) was found to be an effective catalyst for the polyesterification reaction. The kinetics of polyesterification in the presence and absence of a catalyst has been found to follow the second‐order rate equation in equimolar concentrations of the reactants. © 1993 John Wiley & Sons, Inc.