Biodegradable Poly(butylene succinate) Copolyesters Modified by Bioresoured 2,5-Tetrahydrofurandimethanol

Abstract

The problems of fossil-based resources and pollution caused by traditional nondegradable polymers have led to the need for biobased monomers and polyesters, presenting more environmentally friendly features. 2,5-Tetrahydrofurandimethanol (THFDM), a biobased monomer containing an aliphatic ring structure and an ether group, was introduced into the molecular chain of polybutylene succinate (PBS) as a sustainable unit to optimize its performance and improve its sustainability. The poly(butylene-co-tetrahydrofurandimethylene succinate) (PBTS) copolyesters were synthesized using a melt polycondensation method. The copolyesters exhibited relatively high intrinsic viscosity (1.03–1.71 dL/g). The Tg values of PBTS copolyesters increased significantly along with the introduction of THFDM (from −32.2 to −12.9 °C). According to the investigation using WAXD (wide-angle X-ray diffraction) analysis and successive self-nucleating annealing (SSA) measurement, it was revealed that the introduction of THFDM reduced the crystallization ability of PBTS while increasing its crystal content with relatively low lamella thickness. This phenomenon was mainly attributed to the aliphatic rings, which limited the movement and regular stacking of the molecular chains. The degradation rate and toughness of the copolyesters improved due to the decrease of crystallization degree. Meanwhile, the gas barrier property of PBTS slightly decreased but remained at a relatively high level. The permeabilities of O2 and CO2 were lower than that of commercially available PBAT. In summary, the introduction of THFDM not only improved the biobased resources content and the sustainability of copolyesters but also improved the toughness and degradation performance without sacrificing gas barrier performance.