Synthesis and characterization of novel environmentally friendly shape memory polyurethanes based on poly(epsilon-caprolactone) diol/castor oil mixtures

A new category of polyurethane plastics (PUs) was obtained from poly (ε-caprolactone) diol/castor oil mixture as a dual-component of their soft segment and hexamethylene diisocyanate (HDI) as the hard segment. The main aim of this study was to explore the effect of castor oil on content chemical structure, dynamic and mechanical properties and low temperature heat induced shape memory of the obtained polyurethane system. The chemical structure of samples was confirmed by Fourier transforms infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy. Differential scanning calorimetry (DSC) was carried out to study thermal transitions of synthesized polyurethanes. At 50 mol % of oil, the polyurethane showed the highest enhancement in tensile strength (54%) and Young’s modulus (23%) compared to PU-0. The PU containing 50 mol % of oil was nearly recovered by 99%.