【作者】 周畅；

【导师】 李地红；

【作者基本信息】 哈尔滨工业大学 ， 材料学， 2012， 硕士

【摘要】 形状记忆聚合物是一种新型的智能材料，在航空航天和医学领域具有巨大发展潜力。形状记忆聚合物具有成本低、形变量大、低密度、性能可控和多种驱动等优异性能，近年来是科学家研究的热点之一。传统的聚氨酯材料热稳定性，耐水性较差，限制了聚氨酯材料的应用。而有机硅材料具有低表面能，良好生物相容性等性能。有机硅改性聚氨酯材料既包含有机硅树脂良好的耐热性，机械性能，疏水性，同时又拥有传统聚氨酯材料优异的弹性，低密度等。本文成功的通过溶液预聚合的方式将有机硅链段加入到聚氨酯主链中，合成了一系列的形状记忆聚氨酯材料。采用红外光谱分析，X射线衍射分析，扫描电镜分析，表面接触角分析，静态拉伸实验，差示扫描量热分析，热失重分析，动态热机械分析，纳米压痕分析等测试手段分析了微观组织结构、热力学性能和形状记忆效应，并从微观角度入手分析了材料的宏观性能。主要工作：比较不同溶剂对溶液聚合反应的影响程度，最终选择DMF与二甲亚砜的混合溶液为反应体系，反应物两种溶剂的界面处发生反应，增加反应速度。.通过溶剂预聚合反应，成功的将有机硅链段加入到了聚氨酯主链中，通过控制软段分子量和含量，合成了玻璃化转变温度从28.2℃~57.5℃的形状记忆聚氨酯。软段分子量为4000的聚氨酯材料表现出极好的形状记忆性能，在90℃下，只需要23s回复率就可以达到95%。从材料热力学角度指出了熵变是形状记忆材料可以自发从玻璃态转向橡胶态变化的原因。研究了POSS颗粒在聚氨酯基体中的分散情况，同时研究了POSS对聚氨酯基体结晶情况，力学性能，耐热性的影响。结果显示POSS颗粒在1%~5%范围时，分散情况良好，且较大的提高了聚氨酯的热力学性能。本文合成的有机硅改性聚氨酯材料具有溶液驱动特性，可以被去离子水和有机溶剂驱动。并从物理溶胀角度和化学极化角度分析了溶液驱动聚氨酯机理，并证实小分子对聚氨酯材料起着增塑效果。通过降解率实验探讨了生物医学医用上的可能，接触角实验表面有机硅链段富集于聚氨酯表面，极大的提高了材料的疏水性。更多还原

【Abstract】 Shape memory polymer is a novel smart material which has great developmentpotential. Since shape memory polymer have excellent properties such as low-cost,high deformable ability, low-density, controllable performance and variety ofdrivers, it has become one of the hottest field of the smart materials.Conventional polyurethanes (PU) exhibit poor water resistance, thermalstability, which limits the application of polyurethane materials. On the other hand,Poly (dimethyl siloxane)(PDMS) systems have excellent properties including lowsurface energy and biocompatibility. Nowadays, researchers take their eye onPDMS modified polyurethanes. These copolymers not only have better heatresistance, mechanical properties and lower temperature polysiloxanes themselvesbut also have better mechanical strength and low-density than polyurethanes.A new kind of thermoplastic polyurethane containing silicone was investigatedin this study. A series of polyurethanes with shape memory performance weresynthesized by solution-polymerization. The chemical compositions, structures,bulk and surface properties were investigated by using infrared surface quantitativeanalysis technique (FTIR-ATR), surface contact angle, stress–strain analysis, XRD,SEM, DSC, TGA and dynamic mechanical thermal analysis (DMA). It was shownthat the contact angle increased swiftly with raising PDMS content, indicating thatwater resistance ability improved with increasing PDMS content. The memoryperformance was increased as the molecular weight of soft segment. Physicalcrosslinking was improved as hydrogen bond strengthens and further enhancespolymer mechanical properties. The main work is summarized as follows:The degree of reaction of different solvents was compared. The mixed solutionof DMF and dimethyl sulfoxide was chosen on the consideration of interfacialreaction. PDMS was successfully added to the polyurethane main chain by pre-polymerization reaction. Series shape memory polyurethanes whose glass transitiontemperature range from28.2℃to57.5℃were gained by controlling the molecularweight and content of the soft segment.The shape recovery rate of SMPU whose soft segments molecular weight was4000was greater than95%and the shape recovery time was only23s at thetemperature of90℃. The entropy change of the shape memory material was thereason why shape memory polymer can spontaneously shift from the glassy state torubbery state changes from the perspective of the thermodynamics of materials.POSS particles were added in the polyurethane material. The dispersion of POSSparticles in the polyurethane matrix, influence of polyurethane matrix crystallization, mechanical properties and heat resistance were studied. The resultsshow that when the POSS particles were in the range of1%wt to5%wt, thepolyurethane thermodynamic properties was greatly improved.The novel shape memory polyurethane could be driven by de-ionized waterand organic solvent. Physical swelling effect and chemically conjugated interactionwas introduced to confirm the solvent-driven shape memory polyurethane. Thebiomedical predict use was discussed by biomedical degradation experiment. Thewater resistance ability was dramatically increased by adding silicone chain. A self-demolition buckle was designed to use in the field of recovery of waste electricalproducts and drugs active release.更多还原