Synthesis and Properties of Biodegradable Copolyester with Phenyl Side Groups

Poly(butylene adipate terephthalate) (PBAT) is a biodegradable copolyester that has garnered significant attention in recent years. However, its application is limited by low tensile strength and elastic modulus. Current research focuses on copolymerization modifications aimed at enhancing PBAT's performance. In this study, a novel copolyester with phenyl side groups, poly(butylene-co-3-phenoxy-1,2-propylene adipate-co-terephthalate) (PBPAT), is synthesized via melt polycondensation. The impact of varying amounts of the fourth monomer, 3-phenoxy-1,2-propylene glycol (PPDO), on the copolyester's properties is investigated. FTIR and NMR spectroscopy confirm the structure and composition of PBPAT. The molecular weight, thermal properties, mechanical properties, processing characteristics, and hydrophilicity of the copolymers are comprehensively evaluated. The results indicate that PPDO does not affect the crystal structure of PBAT. However, the performance of PBPAT is significantly influenced by the PPDO content, which the optimal mechanical properties are achieved with 12.5% PPDO, demonstrating a tensile strength of 26.1 MPa and an elastic modulus of 220.6 MPa. Furthermore, PBPAT copolyesters exhibit high crystallinity, heat resistance, good hydrophilicity, and superior processability. The novel PBPAT copolyester offers enhanced performance characteristics and holds potential for replace commercial PBAT, thereby expanding the application scope of biodegradable materials.