Catalytic amounts of sodium-sulfonate-naphthol enable mechanically robust, ultra-transparent, super-fire-resistant and easily recyclable polycarbonate.

Polycarbonate is an advanced engineering plastic widely used in aerospace, high-speed rail and 5G communications. However, it remains a huge challenge to synthesize polycarbonate materials using a strategy that simultaneously integrates green-preparation, service-stage advanced-performance and end-of-life easy-recyclability. Herein, we propose an ultrahigh-efficiency and green halogen/phosphorus-free strategy to prepare a mechanically robust, highly transparent, super-fire-resistant and chemically easily recyclable polycarbonate plastic. By chemical copolymerization of only catalytic amounts of sodium sulfonate-naphthol (0.3-0.5 mol%, namely 3400-5600 ppm), the corresponding polycarbonates exhibit >85 MPa tensile strength, >67 kJ m^-2 notched impact strength, >90% transparency, >36% ultra-high limiting oxygen index and 1.6 mm thin-wall UL-94 V-0 rating during the service-stage. Especially, at the end-of-life, these polycarbonates can be easily depolymerized back to the raw monomer bisphenol A and high-value 2-oxazolidinone under mild conditions (50 °C for 4 h), achieving ultra-high atom-economic chemical recycling. Starting from the source of a chemical structure, this work opens up a new perspective for constructing life cycle-managed plastic materials with advanced high-performance and full-recyclability, contributing to the global circular economy through sustainable material design.