Synthesis of degradable polyester with high molecular weight and excellent mechanical properties through copolymerization modification of poly(butylene succinate)†

Maintaining the high mechanical properties of degradable polyesters is crucial for their practical application. In this work, tricyclodecanedimethanol (TCD) with a rigid ring structure was introduced into the synthesis of polybutylene succinate (PBS) to form PBTCDS copolyester. The addition of TCD significantly improved the glass transition temperature (T_g), mechanical properties, and barrier properties of the copolyester. The inherent toughness of PBS is limited by its poor elongation at break, which restricts its application range. However, the tensile strength of PBTCDS5 synthesized in this study is 42 MPa, with an elongation at break of 687%. It is noteworthy that the elongation at break of PBTCDS15 reaches 860%, greatly improving the mechanical properties of PBS. Compared with PBS (T_g −31.4 °C), the T_g of the copolyester increased from −29.2 °C to −22.8 °C, thereby improving its thermal properties. The water vapor barrier test showed that the water vapor transmission rate had improved. In addition, water degradation experiments showed that changing the TCD content resulted in different degradation rates, leading to copolyesters with different degradation rates. Ultimately, this method significantly improves mechanical properties while maintaining degradability, thereby broadening the application scope of PBS.