Random Copolymerization of L-Lactide with Six-membered Cyclic Oxalates Enables Simultaneous Toughening and Tunable Degradation of Poly(L-lactic acid)
Year: 2026
Type: preprint
Abstract: Poly(L-lactic acid) (PLLA) is one of the most important biobased and biodegradable polyesters, but its intrinsic brittleness and slow degradation in natural environments still hamper its extensive applications. Developing PLLA materials that combine high strength and toughness with tunable degradation behavior remains a significant challenge. In this contribution, we present the bulk ring-opening copolymerization (ROCP) of L-lactide (L-LA) with each of three six-membered cyclic oxalates (sAOx), namely ethylene oxalate (EOx), 1,2-propylene oxalate (POx) and 1,2-hexylene oxalate (HOx), to produce a series of P(LLA-co-sAOx) statistical copolyesters using Sn(Oct)2 as the catalyst. The P(LLA-co-POx) statistical copolyesters exhibited the most favorable strength–toughness balance. At a POx content of 15 mol%, the P(LLA-co-POx) copolyester exhibited an elongation at break of 224% and a toughness of 63.7 MJ m-3 while retaining a high yield strength of 50.3 MPa. This toughness was approximately 33 times that of neat poly(L-lactide) (PLLA). In addition, the P(LLA-co-POx) statistical copolyesters exhibited good barrier performance and showed potential application as packaging materials. More importantly, the incorporation of POx endowed the copolyesters with excellent degradability and composition-dependent degradation behavior under natural environmental conditions. The P(LLA-co-POx) copolyester with a POx content of 50 mol% completely degradation within 80 days in soil. This work provides a chemical modification strategy for designing high-performance and sustainable PLLA-based packaging materials.
Source: ChemRxiv
Authors: Yalei Liu, Bin Wang, Yong Shen, Zhibo Li
Language: English
Subfield: Biomaterials
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223323342