【作者】 万春杰；

【导师】 余剑英；

【作者基本信息】 武汉理工大学 ， 材料学， 2007， 博士

【摘要】 近年来，可降解高分子材料因具有绿色环保概念而引起了人们极大的兴趣。并为生态环境以及可持续发展提供一个可能的选择。当前，全世界的高分子材料每年的产量已超过1.2亿吨，使用后产生的不可自然分解的大量废弃物变成污染源，造成地下水质及土壤污染，妨碍动植物生长，危及人类健康和生存。可降解高分子材料为解决废弃物所造成的环境问题提供了较好的途径。而由于成本、技术水平等因素的制约，虽然对可降解高分子材料已有研究和试用，但其发展和应用还远没有达到令人满意的程度。聚碳酸亚丙酯(PPC)是由环氧丙烷和二氧化碳为原料合成的热塑性可降解树脂，但玻璃化温度低、不结晶、力学性能差且对热敏感，应用范围受到限制。聚合物／粘土纳米复合材料(PCN)是以聚合物为基体，粘土以纳米尺度分散于聚合物基体中的新型高分子复合材料，与纯聚合物或传统复合材料相比，其力学性能、热稳定性等方面得到明显提高。若能通过层状硅酸盐纳米复合改善PPC的力学性能和热性能，将具有较大的适用价值和经济意义。本论文采用两种季铵盐作为蒙脱土和累托石的有机改性试剂，通过阳离子交换反应制备有机蒙脱土(OMMT)和有机累托石(OREC)，采用熔融共混法制备了聚碳酸亚丙酯／蒙脱土和聚碳酸亚丙酯／累托石纳米复合材料；采用X-射线衍射(XRD)、透射电镜(TEM)、原子力显微镜(AFM)等手段表征了复合材料的微观结构；差示扫描量热仪(DSC)研究了各种改性体系的热学性能、测试了复合材料的静态力学性能、动态力学性能(DMA)、热稳定性、耐油、耐水和空气老化性等。主要研究结果如下：(1)采用阳离子交换法，制备了不同的有机胺改性的有机蒙脱土和有机累托石，用XRD，FTIR，TGA表征了插层效果。研究结果发现有机季胺盐可与蒙脱土和累托石发生阳离子交换反应得到层间距较大并易于在有机介质中分散的有机蒙脱土和有机累托石。(2)采用熔融插层法，制备了PPC／硅酸盐纳米复合材料，通过X射线衍射、透射电镜(TEM)、原子力显微镜(AFM)对PPC／硅酸盐纳米复合材料的微观结构进行了表征。结果表明有机化蒙脱土和累托石能较好的分散于PPC基体中形成了纳米复合材料。(3) PPC／粘土的静态力学性能研究表明，OMMT和OREC用量为3％时的拉伸强度和冲击强度均最高，7％时的断裂伸长率最小，这种性能与粘土的插层效果、复合材料的微相结构及组分间强烈的相界面作用有关。(4)采用DSC，TGA和DMA等分析仪器对PPC／累托石纳米复合材料的热学性能和动态力学性能进行了研究，结果表明，纳米复合材料的玻璃化转变温度Tg比纯PPC聚合物明显提高，热稳定性、储能模量和损耗模量也有较大提高，而损耗角正切值tand下降。(5) PPC／累托石纳米复合材料的耐介质性能研究结果表明：插层效果较好的复合材料具有较好的耐介质性能，这归因于粘土片层有效地阻止了溶剂分子向材料内部的渗透。PPC／累托石形成插层型纳米复合材料后，PPC的耐水性和耐机油性得到明显改善。更多还原

【Abstract】 Biodegradable polymers from renewable resources have attracted much attention in recent years. Renewable sources of polymeric materials offer an alternative to maintaining sustainable development of economically and ecologically attractive technology. The whole world polymers material output already exceed 120 million tons on every year. The waste coming into being has become a pollution source, lead to ground water quality and soil contaminated, and prevent animal and plant from growing, and endanger human being health. Restraint because of cost and factors such as technology and level, though to biodegradable polymers material already had studying and put on probation, but, it’s the level developing and applying can not be all that could be desired.Poly(propylene carbonate) (PPC) is a new thermoplastic biodegradable polymers derived from carbon dioxide and propylene oxide. However, its poor mechanical properties and thermal stability has limited its application. If its mechanical and thermal properties could be remarkably enhanced through compounding layered silicate such as montmorillonite and rectorite. Will have bigger value suitable for use and economy significance.In this paper, the organic montmorillonite(OMMT) and organic rectorite (OREC) is synthesized through cation exchange reaction with two kinds of quaternary ammonium salt, poly(propylene carbonate)/montmorillonite and poly(propylene carbonate)/rectorite nanocomposites are prepared via melt blending. The microstructures of nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and atomic force microscope(AFM). And its composites is investigated by differential scanning calorimetry (DSC). and wide X-ray diffraction (WXRD). The mechanical properties, dynamic mechanical analysis (DMA), thermogravimeric analysis (TG), oil resistance and water resistance and air abing resistance properties of composites are also investigated. The main results obtained are as follows:(1) The organic ammonium modified montmorillonite and rectorite of different kinds has been prepared using cation exchange in water. The intercalation effect was characterized by XRD,FTIR and TGA. It is found that quaternary ammonium salt and alkylamine can react with montmorillonite and rectorite via cation exchange reaction and the resulting OMMT and OREC can act as nano-scale filler to PPC materials due to its increasingly swollen gallery spacing.(2) Poly(propylene carbonate)/OMMT and Poly(propylene carbonate)/OREC nanocomposites were prepared by melt blending PPC directly with OMMT and OREC. The microstructure, morphology of PPC/clay nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and atomic force microscope(AFM). The XRD pattern and TEM images show that the intercalation of OMMT and OREC in PPC matrix was achieved as revealed and OREC is finely dispersed in PPC matrix.(3) The tensile strength and impact strength of PPC/clay nanocomposites is maximal when the loading of OREC is 3phr and the elongation is minimum when the loading is 7phr, which is associated with the hood compatibility and strong interaction between clay and matrix.(4) The thermal stability properties and dynamic mechanical behavior of the nanocomposites are investigated by DSC,TGA and DMA. The results show that the glass transition temperature (Tg) is increased and that the thermal stability, the storage modulus (E’) and the loss modulus (E") of NC are improved, but the tand are decreased.(5) Chemical Resistance results showed : intercalation better results of composite materials with high dielectric resistance to the better performance, Note composite material effect intercalation good clay layers can effectively prevent the solvent molecules into the interior of infiltration. PPC/OREC formation of intercalated nanocomposites, the PPC water resistance and oil resistance sexual improved noticeably.更多还原