Facile Synthesis of Readily Hydrolyzable Polycarbamates via Alternating Copolymerization of Isocyanates and O -Phthalaldehyde

Abstract While various degradable polymers have been developed to alleviate the long-term hazards of traditional plastics to ecosystems, their efficient degradation commonly requires specific conditions, including alkalinity or high temperature, and remains formidable in most natural environments. Here, we report the first alternating copolymerization of isocyanates and o-phthalaldehyde (OPA) to afford a unique class of naturally degradable polycarbamates (PPAI) featuring highly hydrolytically sensitive N-substituted N-oxymethyl carbamate units. The alternating copolymerization exhibits a divergent sequence selectivity for N-alkyl hemiacetal urethane (AB) and N-alkyl N-oxymethyl carbamate (AB′) linkages, which can be precisely modulated by reaction temperatures. Notably, the resulting copolymers completely degrade into biocompatible products at ambient temperature across multiple natural environments (water, seawater, and atmospheric moisture). The degradation lifetime can be tuned from days to 8 weeks via structural variations, while polymers remain intact under dry conditions. Moreover, by combining diverse commercially available initiator/monomer sets, the copolymerization affords a versatile and accessible platform with high performance and unique hydrolytic degradability, opening access to myriad naturally degradable plastics for single-use applications.