板料弯曲回弹影响因素的有限元模拟研究

Effects of the kinds of liquid crystalline polymers on the structure and properties of the liquid crystalline polymers/epoxy pesin blends

通过静态力学、动态力学实验方法，研究了热致性液晶聚合物（LCP）的种类对环氧树脂共混物在不同温度下的拉伸强度和应力-应变曲线的影响，通过TEM观察了共混物的相形态结构．结果表明，反应型液晶聚合物（LCPU）比其它种类的液晶聚合物对环氧树脂的改性效果更好；在不同温度下，其拉伸强度和应力-应变行为均比其它材料优越；固化物的动态力学结果表明：反应型的液晶聚合物键入了固化网络，出现新的松弛，TEM结果表明，反应型的液晶聚合物在基体材料中形成大小在nm数量级的液晶聚集微区，没有反应基团的液晶聚合物PHBHT在10％的加入量下，与环氧的共混物结构也有液晶聚集微区产生，但是聚集区大小在微米量级．

The effects of the kinds of liquid crystalline polymers on the structure and properties of the thermotropic liquid crystalline polymers（ LCP）/epoxy resin（EP） blends were studied by mechanical properties test, dynamic mechanical properties test, and TEM observation. The results showed that the reactive liquid crystalline polymers （LCPU） were better than other liquid crystalline polymers for epoxy resin modification, the tensile strength and the stress - strain behavior of the LCPU/EP blends were superior to other materials at different temperatures. The investigation on dynamic mechanical properties of cured materials showed that thegαgndgβ relaxation transition shift toward higher temperature and appear another smaller β gelaxation for the reactive LCP/EP blends, and this might be due to the fact that the reactive groups of LCPU （ i. e. , - NCO） reacted with the hydroxyl groups of epoxy resin and slightly changes the microstructure of the crosslinking networks of epoxy. The observation by TEM showed that when LCPU content was less than 15% , the system was a homogeneous system and the liquid crystal were evenly distributed in nanometers, and the structure of the EP/DDS/10% PHBHT composite appeared micro - phase separation and the size of the liquid crystal domain was about 5μm.