Effects of Molecular Weight on the Properties of Biodegradable Poly(pentamethylene furanoate)

With the escalating environmental concerns, public demand for sustainable development has intensified, leading to a growing interest in bio-based polyesters. This study utilized the bio-based monomers furandimethyl dicarboxylate (DMFD) and 1,5-pentanediol (PeDO) to synthesize poly(pentamethylene 2,5-furanoate) (PPeF) homopolymers with number-average molecular weights ranging from 14 to 52K g·mol–1, systematically investigating the effects of molecular weight on the properties of PPeF. Results indicated that higher molecular weights corresponded to slower crystallization rates; after seven months, crystallization was essentially complete, and all samples demonstrated high-modulus rigid plastics. Notably, PPeF (42K) exhibits the best overall mechanical performance, with a maximum tensile strength of 42.1 MPa, a modulus of 1025 MPa, and an elongation at the break of 23%. The biodegradability of PPeF in CALB enzyme and composting environments was confirmed through monitoring of residual weight and molecular weight changes, with residual weights decreasing to 83.9% and 81.8% after 30 days for PPeF (42K), respectively. PPeF demonstrates favorable thermal, mechanical, barrier, and biodegradation properties, indicating its potential for practical applications.