纳米CaCO_3增强增韧PP/弹性体复合材料的研究

Investigations on Nano-CaCO_3 Reinforced and Toughening Polypropylene/Elastomer Composites

采用钛酸酯偶联剂对纳米CaCO_3进行了表面接枝改性,并采用熔融共混法制备了聚丙烯(PP)/乙烯–辛烯嵌段共聚物(OBC)/纳米CaCO_3复合材料,研究了纳米CaCO_3的加入量对复合材料的力学、热力学及流变性能的影响,并观察了复合材料的断面形貌。结果表明,当改性纳米CaCO_3含量为2.5%时,复合材料的力学性能最佳,其中拉伸强度达到27.5 MPa,冲击强度达到16.1 k J/m2,进一步增加纳米CaCO_3含量时,由于纳米粒子之间发生了严重团聚使复合材料力学性能显著下降;纳米CaCO_3的加入对复合材料起到了异相成核的作用,提高了复合材料的结晶温度和结晶度;复合材料中纳米粒子的存在使其复合黏度和储能模量同时升高。

Titanate coupling agent was adopted for surface grafting modification of nano-CaCO3,melt-mixing process was used to prepare polypropylene (PP)/ethylene-octene block copolymer (OBC)/nano-CaCO3 composites. The effects of nano-CaCO3 adding amount on mechanical,thermal and rheological properties of the obtained composites were investigated,as well as the fractured surface morphologies. The results show that when the adding amount of modified nano-CaCO3 reach 2.5%,the maximum values of mechanical properties of the obtained composites appear (tensile strength:27.5 MPa,impact strength:16.1 kJ/m2). The serious aggregation effect of nano-particles lead to a sharp degradation in mechanical properties with further increasing the adding amount of nano-CaCO3. Nano-CaCO3 serve as an effect of heterogeneous nucleating agent,increasing the crystallization temperature and crystallinity of the obtained composites. Furthermore,the complex viscosity and storage modulus of the obtained composites has shown an increase as a result of the presence of nano-particles.