Developments in the Use of Nanotubes in Elastomers

摘要

Multiwall carbon nanotubes (MWNT) used in elastomers yield conductive compounds that exhibit major performance advantages over carbon black-based conductive elastomers. Multiwall carbon nanotubes (MWNTs) are composed of concentric graphitic rings and are about 10 nm (3.9 mil) in diameter and 10 microns (0.4 mil) in length. With a high aspect ratio (length divided by diameter), MWNTs are able to establish a percolating network at a lower loading than other conductive additives. Thermoset elastomers have unique performance features of good chemical resistance and a low durometer (durometer is a measure of surface hardness). Historically, the issue with making these elastomers conductive was that the high loading of a conductive carbon black gave a compound with an unacceptable high durometer. It was felt that if there were some way to incorporate MWNTs into a thermoset elastomer, the result would be superior performance in those areas requiring both static dissipation and good elastomeric performance. Precix Inc., a major manufacturer of sealing systems for automotive, aircraft and industrial uses, developed a nanotube-based conductive fluoroelastomer (FKM) O-ring. This article will present the performance data obtained to date.