Recyclable and Biodegradable Paper Coating with Functionalized PLA and PBAT

Conventional nonfunctional polyester-coated paper is suitable for packaging, but this coated paper is nonrecyclable. Herein, we report paper coating materials recyclable and industrially compostable using functionalized polyester blends. First, carboxylic acid-functionalized polylactic acid (CPLA) and carboxylic acid-functionalized poly(butylene adipate-<i>co</i>-terephthalate) (CPBAT) were synthesized. CPLA, either alone or as a blend of CPLA and CPBAT, was emulsified and then applied for paper coating. The coated paper was tested to evaluate its water and oil repellency, gas and moisture barrier, sealing, and mechanical properties index. The coated paper's repulpability and recyclability were fully validated by certified methods. The compostability of the CPBAT- and CPLA-coated papers was also confirmed. This newly coated paper is PFAS- and persistent microplastics-free, and its recyclable nature fits into a circular economy approach.