A facile method to synthesize bio-based and biodegradable copolymers from furandicarboxylic acid and isosorbide with high molecular weights and excellent thermal and mechanical properties†
Bio-based copolymers with high glass transition temperature (Tg) and good mechanical properties and biodegradability are highly desired for practical applications such as food packaging or in heat-resistant containers. In this work, a series of fully bio-based high-molecular-weight copolymers (PICBF(S)) were successfully prepared from dimethyl 2,5-furandicarboxylate (DMFD), isosorbide (Is), 1,4-butanediol (BDO) and dimethyl succinate (DMS) by a two-step melt polymerization, a facile and green process for practical semi-continuous production. These copolymers showed tunable Tg values varying from 43 to 122 °C and high weight-average molecular weights (Mw) ranging from 87 000 to 42 000 g mol−1. A systematic study of the structure–property relationship revealed that the properties of these copolymers could be easily controlled by simply changing the composition ratio of monomers. In particular, the copolymer PI80CBF10S10 showed a Tg value of 97.6 °C, tensile strength of 69 MPa and tensile modulus of 1330 MPa. Additionally, it showed reduced CO2 (34 times) permeability when compared to that of poly(butylene succinate) (PBS). Also, its degradation weight loss could reach 12.7% after 28 days when incubated with lipases, which was unusual when considering its high Tg. With good gas barrier property and biodegradability, excellent thermostability and high mechanical performance, these sustainable copolymers seem to have broad potential applications in the plastic industries.