TPEE/n-SiO_(2)复合材料的非等温结晶动力学与各向异性  

Non-isothermal Crystallization Kinetics and Anisotropic Mechanical Properties of Thermoplastic Polyester Elastomer/n-SiO_(2) Composites

作　　者：李尚清 何晓东 孙刚伟 Li Shangqing;He Xiaodong;Sun Gangwei(Orinko Advanced Plastics(Shanghai)Co.,Ltd.,Shanghai 200062,China)

机构地区：[1]会通新材料(上海)有限公司,上海200062

出　　处：《工程塑料应用》2023年第4期42-50,共9页Engineering Plastics Application

摘　　要：为研究填料对高黏度复合材料性能的影响,以聚异氰酸酯(PMDI)为固化剂、纳米二氧化硅(n-SiO_(2))为填料,制备了高黏度热塑性聚酯弹性体(TPEE)/n-SiO_(2)复合材料,并运用Jeziorny模型和Ozawa模型研究了该体系的非等温结晶动力学。随着n-SiO_(2)质量分数的增大,TPEE/n-SiO_(2)复合材料结晶周期变宽,对应的结晶焓降低;并且该体系在结晶生长期的Avrami指数(n)与Ozawa指数(m)均随n-SiO_(2)质量分数的增大而减小,非等温结晶速率常数(k_(c))值则随之增大;相比于结晶生长期,在二次结晶期该体系n值明显变小,kc值则变大且不受n-SiO_(2)含量变化的影响保持较稳定状态。此外,适量n-SiO_(2)的加入使TPEE非等温结晶活化能提高,但过量n-SiO_(2)反而使非等温结晶活化能降低。对于注射成型各向异性,该高黏体系在横向方向上的拉伸强度和断裂伸长率均明显高于纵向方向上的;当复合材料中n-SiO_(2)的质量分数由0%增大至5%时,该高黏体系更难以发生取向,导致横纵方向上拉伸强度均下降,而横向方向上断裂伸长率随之增大,纵向方向上断裂伸长率则减小。A high viscosity thermoplastic polyester elastomer(TPEE)composite was prepared by reactive extrusion with polyisocyanate as curing agent and nanosilica(n-SiO_(2))as filler,and the effect of n-SiO_(2) on the properties of the composite was studied.Also,the non-isothermal crystallization kinetics of the composite was studied by Jeziorny model and Ozawa model.It is demonstrated that the crystallization period of the high viscosity TPEE composite becomes wider with the increase of n-SiO_(2) content,and the corresponding crystallization enthalpy decrease significantly.At the same time,both the Avrami index n during the crystallization growth period and Ozawa index m of the composite decrease,while the non-isothermal crystallization rate constant(k_(c))increases.However,during the secondary crystallization period,the n value of the composite decreases significantly,while the kc value increases and is not affected by the change of n-SiO_(2) content.Moreover,n-SiO_(2) with appropriate content increases the non-isothermal crystallization activation energy of the composite,but superfluous n-SiO_(2) significantly reduces its non-isothermal crystallization activation energy.As for the anisotropy of injection molding,the tensile strength and elongation at break of TPEE/n-SiO_(2) composite in the transverse direction are significantly higher than those in the longitudinal direction;When the n-SiO_(2) content increases from 0wt%to 5wt%at transverse direction,the tensile strength of the injection molded composite owning high viscosity hard to orient slightly decrease in both direction as well as the elongation at break in the longitudinal direction,while the elongation at break in the transverse direction is the opposite.

关 键 词：热塑性聚酯弹性体 纳米二氧化硅 结晶动力学 结晶活化能 各向异性 

分 类 号：TQ317.3[化学工程—高聚物工业]