Fabrication of biodegradable Poly(butylene adipate-co-butylene terephthalate) bead foams through solid utilization of chitin and controllable incorporation of porous structure.

The pollution caused by waste plastics is becoming increasingly serious, and utilizing the biodegradable materials, that can be completely degraded in nature, is considered to be one of the most promising ways to solve this problem. Poly(butylene adipate-co-butylene terephthalate) (PBAT), as the commonly used biodegradable polymer material, is subjected to the problem of high cost, poor mechanical performance, and low melt strength at high temperatures. Herein, a novel strategy combining solid utilization of biomass material chitin and incorporation of porous structure was developed to fabricate the PBAT bead foams, relying on the solid-state shear milling (S3M) and supercritical carbon dioxide (scCO 2) foaming technologies. Chitin scraps were super finely pulverized and uniformly combined with PBAT, and the PBAT-based bead foams with controllable cell structure, improved mechanical performance, and low cost after foaming the composite. When the content of chitin was 20%, the tensile strength and Young's modulus of PBAT/chitin bead foam were 0.72 MPa and 2.14 MPa, respectively, much higher than that of neat PBAT bead foam, expressing the great significance to broadening the application field of degradable plastics. [Display omitted] [ABSTRACT FROM AUTHOR]