Disulfide-Driven On-Demand Degradation of the PBAT Copolymer: Stable Comprehensive Performance, Long-Term Storage, and Redox-Induced Degradation
Chen Lin, Han Hu, Hanxu Zhu, Qingyang Luan, Zhenzhong Li, Jinggang Wang, Jin Zhu
Abstract
Common biodegradable polyesters are degraded under favorable conditions, such as industrial compost. Poly(butylene adipate- co -terephthalate) (PBAT) is one of the most prospective and prevalent biodegradable polymer, while its degradation in natural environment is slow. Herein, we introduce a stimulus group with disulfide bonds to obtain a poly(butylene adipate- co -dithiodipropionate- co -terephthalate) (PBADiT) copolyester. Their melting temperature is higher than 120 °C and the thermal stability is sufficient for melt processing. They show high modulus (>110 MPa) and high toughness when ≤30% of disulfide bonds are introduced. BDi (butylene dithiodipropionate) units show slightly lower hydrolysis and enzymatic degradation ability, and PBADiT copolymers show acceptable storage stability in a damp environment. The redox response of PBADiT helps realize on-demand degradation after use. From 0.01 to 1 mol/L H 2 O 2 solutions, the hydrolysis of PBADiT can be regulated or accelerated by 15 days of fast hydrolysis with weight loss exceeding 40%. Reductive conditions, represented by 0.2 mol/L dithiothreitol (DTT) solutions, are also an efficient stimulus source for achieving rapid breakage of PBADiT. Hence, PBADiT copolymers provide a new approach for sustainable and degradable materials with required usage time and impart the polymer with accelerated degradation in redox environments.