Triblock polyester thermoplastic elastomers with semi-aromatic polymer end blocks by ring-opening copolymerization.

Area of Science:

• Polymer Chemistry
• Materials Science
• Sustainable Polymers

Background:

• Thermoplastic elastomers (TPEs) are crucial in various industries due to their elasticity and processability.
• Current TPEs predominantly rely on petroleum, lack degradability, and pose recycling challenges.
• There is a growing need for sustainable and degradable alternatives in the TPE market.

Purpose of the Study:

• To synthesize and characterize novel ABA triblock polyesters as high-performance, degradable thermoplastic elastomers.
• To investigate the structure-property relationships of these new materials.
• To evaluate their potential as sustainable alternatives to conventional TPEs.

Main Methods:

• One-pot synthesis of ABA triblock polyesters {poly(cyclohexene-alt-phthalate)-b-poly(ε-decalactone)-b-poly(cyclohexene-alt-phthalate)} using a Zn(II)/Mg(II) catalyst.
• Controlled ring-opening polymerization of ε-decalactone followed by ring-opening copolymerization with phthalic anhydride and cyclohexene oxide.
• Comprehensive characterization including SEC, TGA, DSC, DMTA, and SAXS.

Main Results:

• Successfully synthesized ABA triblock polyesters (PE-PDL-PE) with controlled block compositions and high conversions (85-98%).
• Materials exhibited distinct glass transitions (PDL: ~-51°C, PE: +138°C) and confirmed phase separation via SAXS.
• Demonstrated excellent thermoplastic elastomer properties: high tensile strength (1-5 MPa), extreme elongation at break (1000-1900%), and 98% elastic recovery.
• Showed a wide operating temperature range (-51 to +138°C), good thermal stability (Td,5% ~300°C), and degradability under mild heating with acid or lipase.

Conclusions:

• The synthesized block polyesters function as high-performance, degradable thermoplastic elastomers.
• These materials offer superior properties and sustainability compared to existing styrenic block copolymers and polylactide-based elastomers.
• The straightforward synthesis provides a platform for developing future TPEs using various monomers.