Design and Characterization of High Gas Barrier and Fully Biobased Poly(1,5-pentylene succinate-co-itaconate-co-furanoate) Elastomers

Biomass feedstock is an accessible alternative to finite fossil chemical resources for fabricating durable and high-performance polymers. In this study, fully biobased poly(1,5-pentylene succinate-co-itaconate-co-furanoate) (PPeSIFs) copolyesters were synthesized by using transesterification and melt polycondensation methods from dimethyl furandicarboxylate, dimethyl succinate, dimethyl itaconate, and 1,5-pentanediol. Dimethyl itaconate was incorporated to provide the cross-linkable reaction sites. Four kinds of monomers were employed to regulate the glass transition temperature and suppress crystallization. Silica/PPeSIF nanocomposites exhibited good mechanical properties, such as an ultimate tensile strength of 17.2 MPa and an elongation at break of 253%. This elastomer displayed outstanding gas barrier properties comparable to those of butyl rubber, with an O₂ permeability 13 times lower than that of natural rubber. Positron annihilation lifetime spectroscopy tests demonstrated that furan moieties significantly reduced the free volume of PPeSIFs. This work provides a promising route for preparing a biobased elastomer with intrinsic high gas barrier properties.