纳米CaCO3对PET／M-POE体系力学性能的影响

采用马来酸酐接枝乙烯-辛烯共聚弹性体(M-POE)和纳米CaCO3协同增韧聚对苯二甲酸乙二酯(PET)。结合复合材料的室温缺口冲击断面扫描电镜照片、淬断刻蚀照片和宏观力学性能,分析了复合体系发生脆-韧转变对应的微观形貌特征。结果表明,直接将M-POE、纳米CaCO3与PET熔融共混并不能起到协同增韧效果,随着纳米CaCO3含量的增加,三元复合体系的缺口冲击强度逐渐降低。纳米CaCO3经过不同表面处理后,在复合体系中的微观分布不同,从而导致体系力学性能变化。不同的加工工艺可以制得纳米CaCO3分布不同的复合材料。研究发现,纳米CaCO3分布于PET基体中会引起复合材料冲击强度的下降。而纳米CaCO3分布于弹性体中,即形成所谓的“沙袋结构”,不仅可以明显提高复合材料的冲击强度,还可降低橡胶用量。

Influence of Nano CaCO_3 on Mechanical Properties of Polyethylene terephthalate/Ethylene-octene Copolymer-grafted-maleic Anhydride Blends

Nano CaCO3 and ethylene-octene copolymer-grafted-maleic(M-POE) were used to toughen PET. Scanning electron microscopy was employed to study the brittle-ductile transition from the morphologies of impact fracture surface and freezed surface. When the content of nano CaCO3 increased, the impact strength of PET/M-POE/nano CaCO3 composites decreased gradually. Surface treating nano CaCQ3 with different agent resulted in different distribution of it. When nano CaCO3 preferably distributed in the PET matrix, the mechanical strength was low, while it preferably distributed in the elastomer, forming a so called "sandbag structure", the impact strength increased apparently.