Novel fully biobased poly(butylene 2,5-furanoate/diglycolate) copolymers containing ether linkages: Structure-property relationships

All the polymers showed a good thermal stability, even higher than that of the thermally stable homopolymer poly(butylene furanoate), and at room temperature appeared as semicrystalline materials. The main effect of copolymerization was a lowering, up to 60 degrees C, in T-m respect to the homopolymer. The dependence of Tm on composition for copolymers was well described by Baur's equation. Diffractometric measurements indicated that only the poly(butylene furanoate) crystalline phase is present in the copolymers under investigation. Amorphous samples showed a monotonic decrement of T-g, up to 30 degrees C, as the content of butylene diglycolate units is increased and this can be explained on the basis of the higher flexibility induced in the polymer chain by the ether-oxygen atoms. A Wood-type equation was found to fit the Tg data of completely amorphous samples.

Novel fully biobased aliphatic-aromatic poly(butylene 2,5-furanoate/diglycolate) random copolyesters were successfully synthesized from 2,5-furandicarboxylic acid, diglycolic acid and 1,4-butanediol through two-stage melt polycondensation using titanium tetrabutoxide and titanium tetraisopropoxide as catalysts. The synthesized polymers were characterized in terms of molecular and solid-state properties, among these, barrier properties to different gases. In addition, biodegradability studies in compost have been conducted.