Curing of poly(furfuryl alcohol) resin catalyzed by a homologous series of dicarboxylic acid catalysts: Kinetics and pot life

Abstract

ABSTRACTCuring kinetics and pot life are two vital characteristics for the application of poly(furfuryl alcohol) (PFA) resin because of the complexities both in the resin composition and curing mechanisms involved. However, few reports have provided a complete picture of PFA curing behavior. In this research, the effect of the addition of catalysts on the pot life and curing behavior of a PFA resin were evaluated. A homologous series of dicarboxylic acids [i.e., oxalic acid (OX), succinic acid (SU), and adipic acid (SA)] were used as the catalysts. Rheometric and nonisothermal differential scanning calorimetry (DSC) measurements and headspace gas chromatography/mass spectrometry analysis were carried out at 0, 6, and 24 h after the addition of the catalyst. The relaxation exponent (n), gel stiffness (S), and gel strength (AF) of the prepared compositions were calculated with the Winter and Chambon and Gabriele rheological models. Furthermore, the curing kinetics were evaluated by the fitting of nonisothermal, multiple‐heating‐rate models. The DSC measurements showed a higher curing degree for samples containing OX catalyst compared to their counterparts containing either SU or AD. The rheometric findings supported an increased stiffness, gel strength, and curing development of the resin in the presence of OX compared to samples containing SU or AD. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44009.