| The thermal-mechanical behavior of the shape memory polyurethane (SMPU) upon temperature stimulation was studied in this report. This study covers five related topics, namely (1) SMPU used as finishing agent, (2) effects of SMPU finishing combined with existing treatments, (3) structure, thermal-mechanical properties and effects of thermal-humidity conditioning for melt-spun SMPU fibers, (4) structure, thermal-mechanical properties and effects of thermal-humidity conditioning of wet-spun SMPU fibers and (5) influence of solvent concentration in coagulation bath of wet-spinning process to SMPU fibers.;SMPU solution is used as an easy-care finishing agent on cotton fabric. The SMPU layer on cotton fabric provides a recovery force during heating, resulted in a better flat appearance and crease retention upon thermal stimulation. Comparing with the traditional easy-care finishing method, SMPU finishing has the advantages of high strength retention and zero formaldehyde content. Micro-Raman spectroscopy was used and the result indicates that internal stress of treated cotton yarn was reduced after combining the SMPU and existing easy-care treatments. This result suggests a reaction mechanism of SMPU treatment.;SMPU fibers prepared by wet and melt-spinning process were conditioned at two humidity levels and two temperature levels for different time. The shape memory effects, thermal-mechanical properties, chemical structure and crystallinity of the SMPU fibers were affected by the temperature-humidity conditioning.;Influences of solvent concentrations in coagulation bath to the wet-spun SMPU fibers were studied. A better shape recovery and fixity ratio existed in fibers spun in higher solvent concentrations. As a trade off, the crystallinity and the breaking tenacities of the SMPU fibers decreased with the solvent concentration.;The structures, thermal-mechanical properties of the newly developed SMPU as a textile material were studied in this project. The research results build up knowledge basis for the development of SMPU based smart textile materials. |
