Catalyst effects found in thermal and mass spectrometric analyses of polycarboxylic acids used as durable press reactants for cotton

Effective polycarboxylic acids (PCAs) crosslink cotton cellulose by an ester linkage and smooth‐drying fabrics are produced. The presence of a catalyst improves the crosslinking reaction. A series of seven PCAs was examined by thermal analytical (TA) and mass spectrometric (MS) techniques. The focus of this research was to discover if catalyst effects were measurable by TA and MS and to seek additional support for a proposed mechanism of cellulose/organic acid reactivity via acid anhydride formation. Thermal analyses consisted of differential scanning calorimetric (DSC) and thermogravimetric (TG) procedures. MS analyses, using the electron impact mode, were performed by direct probe sample insertion. Observed catalyst effects included shifts in peak positions to lower temperature/time, and were noticeable primarily in MS‐reconstructed ion current chromatograms and DSC thermograms. Two TG parameters, the amount of residue produced and the rates of weight loss, offer ways to predict the effectiveness of a PCA with respect to smooth‐drying character. The presence of the catalyst influenced both measurements in desirable directions. Finally, the catalyst did not alter TG water loss data that support the proposed mechanism of reaction with cellulose via an anhydride intermediate.