High-Strength, Self-Healing, Recyclable, and Catalyst-Free Bio-Based Non-Isocyanate Polyurethane

Abstract

Non-isocyanate polyurethanes (NIPUs) from renewable resources have attracted wide attention because of their remarkable benefits to sustainable development and green production. In this work, a strong, self-healing, and catalyst-free NIPU(ECMP)was prepared based on the hyperbranched bio based cyclic carbonate (Ec-MTDA) synthesized through catalytic carbonization of 1,8-menthanediamine (MTDA) and CO2.The hyperbranched and rigid structures of ECMP enable improved mechanical properties that ahigh tensile strength of up to 34.9 MPa can be achieved. Benefiting from the dynamic trans esterification reaction between the carbamate and hydroxyl groups, ECMP presents favorable self-healing, reprocessing properties, and shape memory. Notably, 91% of the original tensile strength can be recovered after self-healing behavior. In addition, abundant polar groups provide excellent adhesion properties for ECMP with a high shear strength of 7.09 MPa. This study provides a promising strategy for the design of bio-based NIPUs, which broadens their applications in printing, furniture, packaging, and other industries