特殊形态结构导电高分子复合材料的电学性能

Electrical Properties of Conductive Polymer Composites With Special Morphology

先使聚丙烯接枝马来酸酐(PP-g-MAH)与炭黑(CB)反应,再与聚丙烯/尼龙6(PP/PA6)共混制备出CB位于两相界面处的PP/PA6/PP-g-MAH/CB导电高分子复合材料,研究了材料的特殊结构和电学性能。结果表明,在PP/PA6/CB体系中CB粒子分布在PA6相,体系的逾渗阈值为2%;而在PP/PA6/PP-g-MAH/CB体系中,CB被PP-g-MAH诱导分布在两相界面处。PP/PA6两相为海岛结构时,PP/PA6/PP-g-MAH/CB体系仍可导电。PP/PA6/PP-g-MAH/CB体系的逾渗阈值降至1.6%,低于PP/PA6/CB体系。体系的正温度效应(PTC)强度远高于PP/PA6/CB体系,在90-135℃范围内不出现负温度效应(NTC)。PP/PA6/PP-g-MAH/CB体系的电学性能归结于其特殊的界面形态结构:导电通道由位于共混物界面处的PP-g-MAH和CB构建而成。

The maleic anhydride grafted polypropylene （PP-g-MAH） was first reacted with carbon black （CB） and then blended with polypropylene/nylon6 （PP/PA6） to prepare the PP/PA6/PP-g-MAH/CB composites. The special morphology and electrical properties of the composites were investi- gated. The results show that in PP/PA6/CB blends, CB preferentially localizes in the PA6 phase and the percolation threshold is 2%. However, in the PP/PA6/PP-g-MAH/CB blends, CB particles can be induced by PP-g-MAH to localize at the interface. The composites of PP/PA6/PP-g-MAH/CB have conductivity even when PA6 and PP phases form sea-island morphology. The percolation threshold of PP/PAO/PP-g-MAH/CB is 1.6%, which is lower than that of PP/PA6/CB. Moreover, the PTC （pos- itive temperature coefficient） intensity of PP/PAO/PP-g-MAH/CB composites is stronger than that of PP/PAO/CB, and the negative temperature coefficient （NTC） effect was eliminated within the temperature range of 90 and 135 ° C. The electrical properties of PP/PAO/PP-g-MAH/CB can be explained in terms of its special interface morphology： PP-g-MAH and CB localize at interface to form the conductive pathways.