Preparation And Properties Research On Tetra-needle Like ZnO Whiskers/shape Memory Polyurethane Composites

In this paper, Tetra-needle like ZnO whiskers (T-ZnOw) was utilized to prepareT-ZnOw/shape memory polyurethane (SMPU) composites with its unique three-dimensionalstructure, excellent mechanical properties, heat resistance and electrical properties, which wasexpected to improve the strength, heat resistance and conductive properties of SMPU, andexpand its application area.The good performance of T-ZnOw/SMPU composites should be based on the gooddispersion of T-ZnOw in SMPU, therefore, in order to prepare T-ZnOw/SMPU composites withfavorable synergistic effect, polyethylene glycol(PEG) dispersant and KH570silane couplingagent were used to modify T-ZnOw respectively, which could resolve the key problem thatT-ZnOw is hard to combine with and evenly disperse into SMPU because of its big surfaceenergy. Afterward, the surface of T-ZnOw before and after treatment was characterized, and theresult showed that the treated T-ZnOw is well loaded with silane coupling agent and dispersant.On the basis of surface modification, T-ZnOw/SMPU composites were prepared by mixedsolution method. Research shows that composites prepared by treated T-ZnOw are improved intensile strength and storage modulus, when the content of T-ZnOw is up to3wt%, the tensilestrength enhances more than3times than that of pure SMPU, elastic modulus andthermostability of the composites are also increased. After incorporated with T-ZnOw, thecrystallinity of SMPU has decreased somewhat, but its degree of destruction caused by surfacetreated T-ZnOw is smaller than untreated one.The Tg value of SMPU combined with modifiedT-ZnOw is somewhat increased, especially when the content of T-ZnOw is3wt%, it increasedmore than20℃compared with pure SMPU. There is a large decline in volume resistivity as thecontent of T-ZnOw rise up from1wt%to3wt%, then the decline becomes slowly with thecontent of T-ZnOw increased continuously. Moreover, it is found that the conductive propertiesof surface treated T-ZnOw/SMPU composites is better than that of untreated one. When thesurface of T-ZnOw is loaded with Ag particles, the volume resistivity of the composites reducesgreatly.