Designing Biobased Poly(ethylene-co-isosorbide terephthalate) Copolyesters with Tunable Properties and Degradability

Area of Science:

• Polymer Chemistry
• Materials Science

Background:

• Developing high-performance polyesters with controlled degradability is a significant challenge in materials science.
• Tailoring polyester properties for specific applications requires innovative monomer incorporation.

Purpose of the Study:

• To synthesize and characterize poly(ethylene-co-isosorbide terephthalate) (PEIT) copolyesters with varying isosorbide (IS) content.
• To investigate the impact of IS incorporation on the thermal, mechanical, optical, and degradation properties of PEIT.
• To assess the potential of these novel copolyesters for applications in transparent thermal packaging.

Main Methods:

• Synthesis of PEIT copolyesters using tetrabutyl titanate (TBT) as a catalyst, with IS content ranging from 0 to 20 mol %.
• Characterization of thermal properties (glass transition temperature, Tg), mechanical properties (tensile strength), and optical properties (light transmittance).
• Evaluation of hydrolytic degradation susceptibility through alkaline degradation studies in 0.1 M NaOH solution.

Main Results:

• Increasing IS content effectively tailored the thermal and mechanical properties of PEIT, raising Tg from 80 to 101 °C and tensile strength from 58.8 to 68.7 MPa.
• Excellent transparency was maintained, with light transmittance up to 90%, making the material suitable for visual applications.
• IS incorporation significantly enhanced hydrolytic degradation; PEIT-20 exhibited approximately 3.5 times greater weight loss than PET under alkaline conditions after 50 days.

Conclusions:

• The incorporation of isosorbide into polyethylene terephthalate (PET) offers a viable strategy for creating high-performance copolyesters with tunable properties.
• PEIT copolyesters demonstrate adjustable degradation rates, enhanced thermal stability, and maintained optical clarity.
• These findings present a promising approach for developing advanced, degradable materials for transparent thermal packaging and other demanding applications.