In-depth study of the synthesis of polyamides in the melt using biacetal derivatives of galactaric acid

In recent years, the incorporation of sugar-derived, cyclic moieties into polymer structures is gaining the interest of researchers and industry. Factors like the general availability of carbohydrate sources and the unique properties of polymers therefrom contribute to their popularity, but on the other hand the presence of additional functional groups e.g. cyclic acetal, might lead to side reactions. The aim of this study is to investigate the different processes occurring during polymerization of 2,3:4,5-di-O-isopropylidene-galactarate (GalXMe) and 2,3:4,5-di-O-methylene-galactarate derivatives (GalXH). The substrates and the polymers obtained by means of the melt polycondensation of ester functionalized monomers and polyamide salts are analyzed by combined TGA, GPC, NMR, LC-MS and Maldi-ToF techniques. Furthermore, melt polymerization of polyamide salts was followed by TGA-MS, which allowed identifying degradation products produced during the polymerization.