A Biobased Bicyclic Monomer toward Poly(butylene terephthalate) Copolyesters with Dual Closed-Loop Recyclability and...

Area of Science:

• Polymer Chemistry
• Materials Science
• Sustainable Chemistry

Background:

• Poly(butylene terephthalate) (PBT) copolyesters face challenges in achieving both high performance and efficient closed-loop recycling.
• Developing sustainable alternatives to petroleum-based plastics is crucial for environmental conservation.

Purpose of the Study:

• To synthesize a novel biobased rigid diol from 5-hydroxymethylfurfural (HMF) and trimethylolpropane (TMP).
• To create PBT-based copolyesters (PBTxBTHy) incorporating this diol and evaluate their properties and recyclability.
• To demonstrate a dual closed-loop recycling strategy for the developed copolyesters.

Main Methods:

• Acid-catalyzed acetalization reaction to prepare the biobased diol (HT).
• Copolymerization of HT with PBT to form PBTxBTHy copolyesters.
• Characterization of thermomechanical properties (e.g., glass transition temperature, strength) and UV shielding.
• Investigation of dual closed-loop recycling via selective acetal or ester bond cleavage.

Main Results:

• Successfully synthesized a biobased rigid diol (HT) from HMF and TMP.
• PBTxBTHy copolyesters exhibited enhanced thermomechanical properties (e.g., Tg of 47.3 °C, strength of 43 MPa for PBT80TT20) and UV shielding compared to PBT.
• Achieved dual closed-loop recycling pathways, recovering valuable monomers or PBT for repolymerization.

Conclusions:

• The biobased diol (HT) is an effective precursor for high-performance PBT-based copolyesters.
• The developed PBTxBTHy copolyesters possess excellent physical properties and dual closed-loop recyclability.
• This approach offers a sustainable route for advanced polymer materials with improved environmental profiles.