Isomannide-Containing Poly(butylene 2,5-furandicarboxylate) Copolyesters via Ring Opening Polymerization

Cyclic oligomers of isomannide 2,5-furandicarboxylate were synthesized using the high dilution condensation method. A mixture of dimer, trimer, and tetramer species largely enriched in dimer was obtained. These cyclic oligomers were made to react with oligo (butylene 2,5-furandicarboxylate) in bulk at 220 degrees C by ring opening polymerization using Sn(Oct)(2) as a catalyst. A series of random poly(butylene 2,5-furandicarboxylate) copolyesters containing isomannide in a range of 5-50 mol % and with weight-average molecular weights between 30,000 and 50,000 g.mol(-1) were prepared. These copolyesters started to decompose above 300 degrees C, and only those containing less than 10 mol % of isomannide showed signs of crystallinity. They displayed glass-transition temperatures in the 40-100 degrees C range with values increasing steadily with the content in isomannide. At difference with poly(butylene 2,5-furandicarboxylate) homopolyester that is reluctant to undergo hydrolysis, the isomannide-containing copolyesters were noticeably degraded by water, much more rapidly when exposed to lipases.