AI-Driven Design of poly(ethylene terephthalate)-replacement copolymers

TL;DR

This paper introduces an AI-driven pipeline for designing PET-replacement copolymers, successfully identifying known alternatives and synthesizing new candidates validated through experimental characterization.

Contribution

The study develops a virtual synthesis and machine learning framework to rapidly design and validate new PET-like polymers, including experimentally confirmed novel candidates.

Findings

Identified 1,108 promising PET-like polymers with predicted properties.

Successfully rediscovered known PET alternatives, validating the approach.

Synthesized and characterized new polymer candidates, confirming the design pipeline's effectiveness.

Abstract

Poly(ethylene terephthalate) (PET), a widely used thermoplastic in packaging, textiles, and engineering applications, is valued for its strength, clarity, and chemical resistance. Increasing environmental impact concerns and regulatory pressures drive the search for alternatives with comparable or superior performance. We present an AI-driven polymer design pipeline employing virtual forward synthesis (VFS) to generate PET-replacement copolymers. Inspired by the esterification route of PET synthesis, we systematically combined a down-selected set of Toxic Substances Control Act (TSCA)-listed monomers to create 12,100 PET-like polymers. Machine learning models predicted glass transition temperature (Tg), band gap, and tendency to crystallize, for all designs. Multi-objective screening identified 1,108 candidates predicted to match or exceed PET in $T_{\rm g}$ and band gap, including the ``rediscovery'' of other known commercial PET-alternate polymers (e.g., PETG, Tritan, Ecozen) that provide retrospective validation of our design pipeline, demonstrating a capability to rapidly design experimentally feasible polymers at a scale. Furthermore, selected, entirely new (previously unknown) candidates designed here have been synthesized and characterized, providing a definitive validation of the design framework.