聚酯液晶/环氧树脂复合材料的合成及应用

Preparation and Properties of Liquid Crystalline Polyester/Epoxy Resin Composites

以4,′4-二（β-羟乙氧基）联苯（BP2）、对苯二甲酰氯（TPC）为原料,吡啶为催化剂,通过溶液聚合法合成一种含有联苯基的新型聚酯液晶（DCLP）。采用红外光谱（FT-IR）、偏光显微镜（POM）及X射线衍射（WAXD）对DCLP的分子结构和液晶性进行表征,然后将该聚酯液晶与环氧树脂（E-44）共混制备聚酯液晶/环氧树脂复合材料,并对其性能进行研究。实验结果表明,加入3%的DCLP,可使复合材料的冲击强度由26.2kJ/m2提高到47.7kJ/m2,拉伸强度和弯曲强度也有不同程度的提高,热分解温度提高10℃~20℃。冲击断面的扫描电镜（SEM）分析表明,聚酯液晶对环氧树脂固化物有明显的增韧效果。

Using pyridine as catalyst ,a new kind of liquid crystalline polyester （DCLP） containing diphenylnate was synthesized by solution polymerization of 4, 4＇-bis-（2-hydroxyhexoxy）biphenyl （BP2） and paraphthaloyl chloride, then characterized by means of FT-IR,POM and WAXD. The observation of POM shows that the liquid Crystalline polyester is a thermotropic nematic liquid crystalline polymer. The properties of DCLP were characterized. DCLP was used to modify the conventional epoxy resin （E-44）. Experimental results reveal that the impact strength of the epoxy resin modified with DCLP increases from 26.2 kJ/m2 to 47.7 kJ/m2, and the tensile strength as well as the bending strength is also improved. The thermal decomposition temperature of modified systems is also 10 ℃-20 ℃ higher than that of the unmodified system. The SEM micrographs of impact fracture show that cured product of epoxy has a significant toughening effect.