Fully biobased triblock copolyesters from l-lactide and sulfur-containing castor oil derivatives: Preparation, oxidation and characterization

Abstract

The synthesis and characterization of fully biobased ABA triblock copolyesters from PLA and castor oil derivatives are described. The synthetic strategy uses a dihydroxy telechelic polyester as a macroinitiator for the ring opening polymerization of l-lactide. This macroinitiator was obtained from a sulfur-containing hydroxyacid derivative of 10-undecenoic acid, which undergoes self-polycondensation with low amounts of biobased 1,4-butanediol, enables the obtention of two prepolymers of different weight. Two series of triblock copolyesters with different percentage of PLA contents were prepared and the resulting thioether-bearing copolyester oxidized to polysulfones. Both series of copolyesters showed improved thermal stability, decrease of crystallinity and a similar hydrophilicity with respect to the PLA homopolymer.