Chemically circular, mechanically tough, and melt-processable polyhydroxyalkanoates

• DOI: 10.1126/science.adg4520
• Publication Date: 2023-04-06T17:58:23Z
• Authors: Li Zhou; Zhen Zhang; Changxia Shi; Miriam Scoti; Deepak K. Barange; Ravikumar R. Gowda; Eugene Y.-X. Chen
• Keywords: Thermal Stability; Brittleness; Degradation

Polyhydroxyalkanoates (PHAs) have attracted increasing interest as sustainable plastics because of their biorenewability and biodegradability in the ambient environment. However, current semicrystalline PHAs face three long-standing challenges to broad commercial implementation application: lack melt processability, mechanical brittleness, unrealized recyclability, last which is essential for achieving a circular economy. Here we report synthetic PHA platform that addresses origin thermal instability by eliminating α-hydrogens repeat units thus precluding facile cis-elimination during degradation. This simple α,α-disubstitution enhances stability so substantially become melt-processable. Synergistically, this structural modification also endows with toughness, intrinsic crystallinity, closed-loop chemical recyclability.