Abstract
Composite of MWCNT and PMMA was prepared by the mean of in-situ polymerization assisted by sonicated mixing. The prepared composites could exhibit electrical conductivity due to conductive path of entangling MWCNT in the polymeric matrix. With the increasing MWCNT content, the conductive path became more uniform, leading to the lower electrical resistance of the composites. Based on experimental results, the 2.0 wt% of MWCNT to PMMA was considered as the percolation threshold. When the composite was exposed to toluene, the polymer matrix would swell, leading to destruction of conductive path and change of the electrical resistance of the composites. Dependence of the sensor sensitivity upon the MWCNT was experimentally investigated. With the lowest MWCNT content, degree of swelling in the composite matrix became much higher. Therefore, the electrical resistance of the composite with the lowest MWCNT content changed substantially.
