Extrusion Research And Preparation Method Of Multiple Shape Memory Polymer Based On Polyurethane

The emergence of shape memory polymer materials has given them a shock who use the traditional way to design and use the traditional materials. SMPs do not only inherit the excellent characteristics such as low density, large amount of deformation of traditional polymer material, but also have its own unique characteristic ‘deformation–recovery’ ability, that can make it play an important role in the fields of biological medical, aerospace, precision instrument manufacturing and so on. Similarly, multiple ability of ‘deformation–recovery’ brought by the emergence of multiple shape memory polymer has pushed the application of intelligent materials to a new height. In the era of pursuing fast rhythm and high efficiency, the 3D printing technology in other words the rapid prototyping technology shorten the distance between ordinary people and the manufacturing, so union the shape memory polymer and 3D printing technology in an organic way will expand the scope of 3D printing materials, make the shape memory materials products have a more precision degree and bigger scope of using, that is the result of win-win.The first main research content is using the method of prepolymerization-chain extension to compound the SMPU with different soft material and hard material. By comparing the influence of different soft segment materials on synthesis process, we picked the soft segment PCL as the main material selection. After many repeated experiments, we get the different proportion of hard and soft segments of SMPU. With results of analyzing the transition temperature as well as the macroscopic properties of the material, finally we choose the MDI:PCL:BDO = 2:1:1 of shape memory polyurethane as an effective experiment scheme and one of raw materials of the follow-up experiments. The glass transition temperature of this SMPU is 37℃, and its shape recovery rate can reach 95%, this part also explore and analysis the application of shape memory polyurethane.Secondly, by using the method of blending modification and referencing material properties of triple shape memory polymer, we design a lot of experiments by selecting multiple sets of different materials, including PPC and PLA, PPC and PU, PLA and PS, SMPU and ABS, and so on. After comprehensively considering the glass transition temperature, material stratification and macro mechanical properties of those mixed material, we eventually find SMPU with ABS blending materials possess the characteristics of the triple shape memory, and its response rates close to 90% of each phase, we also analysis the promoting effect of benzene ring on the shape memory capacity of material and the triple shape memory mechanism: Tm of ABS chain segment and Tg of SMPU chain segments can be thought as two reversible changes in the material, the crosslinking structure between the two as the existence of the stationary phase, at last we design its medical applications.Finally we use the triple shape memory materials to make filaments in order to studying the possibility of its application in 3D printing. Through the experiments of different way of extrusion and the impact of temperature for extrusion materials, we design the appropriate plan to make filaments with the suitable wire extrusion temperature 170℃, finally got the print parts. Analyzing the shape memory capability of printing, its recovery rate is about 90%. The result is that the especial material is suitable for 3D printing. It will greatly enriched the using range of this material.