Biodegradable\nPoly(butylene succinate) Copolyesters\nModified by Bioresoured 2,5-Tetrahydrofurandimethanol

Abstract

The problems of fossil-based resources and pollution\ncaused by\ntraditional nondegradable polymers have led to the need for biobased\nmonomers and polyesters, presenting more environmentally friendly\nfeatures. 2,5-Tetrahydrofurandimethanol (THFDM), a biobased monomer\ncontaining an aliphatic ring structure and an ether group, was introduced\ninto the molecular chain of polybutylene succinate (PBS) as a sustainable\nunit to optimize its performance and improve its sustainability. The\npoly­(butylene-<i>co</i>-tetrahydrofurandimethylene succinate)\n(PBTS) copolyesters were synthesized using a melt polycondensation\nmethod. The copolyesters exhibited relatively high intrinsic viscosity\n(1.03–1.71 dL/g). The <i>T</i>_g values\nof PBTS copolyesters increased significantly along with the introduction\nof THFDM (from −32.2 to −12.9 °C). According to\nthe investigation using WAXD (wide-angle X-ray diffraction) analysis\nand successive self-nucleating annealing (SSA) measurement, it was\nrevealed that the introduction of THFDM reduced the crystallization\nability of PBTS while increasing its crystal content with relatively\nlow lamella thickness. This phenomenon was mainly attributed to the\naliphatic rings, which limited the movement and regular stacking of\nthe molecular chains. The degradation rate and toughness of the copolyesters\nimproved due to the decrease of crystallization degree. Meanwhile,\nthe gas barrier property of PBTS slightly decreased but remained at\na relatively high level. The permeabilities of O₂ and CO₂ were lower than that of commercially available PBAT. In summary,\nthe introduction of THFDM not only improved the biobased resources\ncontent and the sustainability of copolyesters but also improved the\ntoughness and degradation performance without sacrificing gas barrier\nperformance.