Evaluation of the performance of azobenzene liquid-crystal shape memory polyurethanes with photo-thermo-synergy responses

Abstract

This study is aimed at investigating the photo-response performance of a polymeric material using a series of azobenzene liquid-crystal shape memory polyurethanes (DB-SMPn) with azobenzene-4,4′-dicarboxylic acid (ADA), N,N-bis(2-hydroxyethyl)isonicotinamine (BINA), and hexamethylene diisocyanate (HDI) as the main raw materials. The mole ratios of BINA and ADA were varied during the preparation of the different hard segment contents of DB-SMPn. The structure, thermal performance, and liquid-crystal properties of DB-SMPn were investigated, and the thermo- and photo-response shape memory performances of DB-SMPn were directly characterized via heating and ultraviolet light. The results indicated that the polymer exhibited excellent triple-shape memory and unique photo-thermo-synergy response shape memory characteristics. These characteristics provided a theoretical basis for the azobenzene liquid-crystal shape memory polyurethane materials, which are expected to have several new potential applications in robotics and smart devices.