Renewable Castor-Oil-based Waterborne Polyurethane Networks: Simultaneously Showing High Strength, Self-Healing, Processability and Tunable Multishape Memory

Angew Chem Int Ed Engl. 2021 Feb 19;60(8):4289-4299. doi: 10.1002/anie.202014299. Epub 2020 Dec 22.

Abstract

Materials with multifunctionality or multiresponsiveness, especially polymers derived from green, renewable precursors, have recently attracted significant attention resulting from their technological impact. Nowadays, vegetable-oil-based waterborne polyurethanes (WPUs) are widely used in various fields, while strategies for simultaneous realization of their self-healing, reprocessing, shape memory as well as high mechanical properties are still highly anticipated. We report development of a multifunctional castor-oil-based waterborne polyurethane with high strength using controlled amounts of dithiodiphenylamine. The polymer networks possessed high tensile strength up to 38 MPa as well as excellent self-healing efficiency. Moreover, the WPU film exhibited a maximum recovery of 100 % of the original mechanical properties after reprocessing four times. The broad glass-transition temperature of the samples endowed the films with a versatile shape-memory effect, including a dual-to-quadruple shape-memory effect.

Keywords: multishape memory; plant oil; processability; simultaneous self-healing; waterborne polyurethane.