热致性液晶聚酯酰亚胺的合成及其改性聚醚酰亚胺的研究

发布时间：2018-05-18 21:54

本文选题：二酰亚胺二酸 + 热致性液晶聚酯酰亚胺　；参考：《西南科技大学》2015年硕士论文

【摘要】：聚醚酰亚胺(PEI)是一种热塑性的聚酰亚胺,具有优良的耐热性、绝缘性、耐溶剂性以及出色的机械性能等优点,可广泛应用于电子、航空航天和医疗设备等领域。但是,由于PEI分子链刚性大,熔点高,造成PEI成型加工成本高,加工难度大等问题。而热致性液晶高分子材料(TLCP)具有良好熔融加工性能、尺寸稳定性,自增强等特点,故使其原位增强改性PEI等热塑性材料成为研究热点。本论文,采用改进的Higashi直接缩合法合成了四个不同系列具有液晶行为的热致性液晶聚酯酰亚胺(TLCPEI),采用红外,核磁表征TLCPEI的结构,通过差热扫描量热仪(DSC)、广角X-射线衍射仪(WAXD)和偏光显微镜(PLM)表征TLCPEI的液晶行为,采用热分析仪表征TLCPEI的热稳定性。测试的结果表明,合成了相应结构的TLCPEI,并且,TLCPEI具有良好的热致性液晶行为。然后,采用注塑成型的方式制备了TLCPEI/PEI原位复合材料,并通过改变TLCPEI的用量,研究TLCPEI对复合材料力学性能影响,为了进一步研究TLCPEI对复合材料力学性能影响,通过扫描电镜(SEM)观察复合材料的断面形貌。结果表明,在不添加改性剂的条件下,添加少量TLCPEI就能获得具有良好力学性能的新型PEI基复合材料。
[Abstract]:Polyetherimide (PEI) is a thermoplastic polyimide with excellent heat resistance, insulation, solvent resistance and excellent mechanical properties. It can be widely used in electronic, aerospace and medical equipment. However, because of the high rigidity of PEI molecular chain and high melting point, the cost and difficulty of PEI molding are high. The thermotropic liquid crystalline polymer (TLC) has the advantages of good melting processing property, dimensional stability and self-reinforcement, so it has become a hot spot in the field of thermoplastic materials such as in-situ reinforced modified PEI. In this thesis, four series of thermotropic liquid crystalline polyester imide (TLCPEI) with liquid crystal behavior were synthesized by modified Higashi direct shrinkage method. The structure of TLCPEI was characterized by IR and NMR. The liquid crystal behavior of TLCPEI was characterized by differential scanning calorimeter (DSC), wide angle X-ray diffractometer (WAXD) and polarizing microscope (PLM). The thermal stability of TLCPEI was characterized by thermal analyzer. The results show that the corresponding structure of TLCPEI has been synthesized and TLCPEI has good thermotropic liquid crystal behavior. Then, TLCPEI/PEI in-situ composites were prepared by injection molding, and the effect of TLCPEI on the mechanical properties of composites was studied by changing the amount of TLCPEI. In order to further study the effect of TLCPEI on the mechanical properties of composites, The cross section morphology of the composite was observed by scanning electron microscope (SEM). The results show that a new type of PEI matrix composites with good mechanical properties can be obtained by adding a small amount of TLCPEI without adding modifier.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ323.7;TB332

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