复合体系中微观相界面对材料性能的影响 Ⅱ反应性偶联剂体系对HDPE/CaCO_3的增韧效果

Influence of Micro - interface on Material Properties in the Composite Ⅱ Toughening Effect of the Reactive Coupling Agent Systems on the HDPE/CaCO3 Composite

根据高密度聚乙烯/碳酸钙(HDPE/CaCO_3)复合体系中各种相界面的特征,把CaCO_3和偶联剂之间通过某种物理化学作用所形成的相界面称之为第1相界面,把偶联剂和HDPE基体之间通过缠绕等作用所形成的相界面称之为第2相界面,考察了反应性偶联剂和助偶联剂对HDPE/CaCO_3复合体系中第2相界面的强化作用及其对复合体系增韧效果的影响。结果表明,反应性偶联剂和助偶联剂在体系中的反应可实现对偶联剂分子链的延长,其结果不仅使HDPE树脂的脆韧转变提前,而且使HDPE/CaCO_3复合体系的韧性大大提高,最高可达基体树脂的12倍左右;CaCO_3对HDPE树脂的增韧行为主要受偶联剂的种类和CaCO_3的添加方法的影响,在使用同种偶联剂处理的情况下,基体树脂的韧性等因素均不会改变其对HDPE树脂的增韧效果和倾向;在本研究使用反应性偶联剂和助偶联剂的条件下,发现基体树脂的分子量较低时,HDPE/CaCO_3复合体系的缺口冲击强度提高较大。

In this paper, the phase interface formed between CaCO3 and coupling agents through certain physical or chemical action was defined as the first - phase - interface and the one formed between coupling agent and HDPE resin through entanglement was defined as the second - phase - interface in terms of the characteristics of various interfaces in the HDPE/CaCO3 composite. The strengthening action of the reactive coupling agent accompanied by the co - coupling agent on the second - phase - interface and their toughening effect on the HDPE/CaCO3 composite was examined in detail. The results indicated that in the system the reaction between the reactive coupling agent and co - coupling agent could lengthen the molecular chains of the coupling agents. As a result, not only occurred much earlier the brittle - ductile transition of HDPE resin, but also the impact toughness of the HDPE/CaCO3 composite was greatly improved, up to 12 times of the matrix. The toughening effect of the CaCO3 on the HDPE resin mainly depended on both the kinds of coupling agents and adding methods of CaCO3. In the case of the same coupling agents were used, other factors such as toughness of the matrix resin could not influence the toughening effect of CaCO3 on HDPE resin. The izod impact strength of the composites was improved more obviously if the matrix resin had relatively low molecular weight.