The Structure and Electro-mechanical Properties of Novel Hybrid CNT/PANI Nanocomposites

Electrically conductive elastomeric nanocomposites containing carbon nanotubes (CNT) and polyaniline (PANI) are reported in the present investigation. The synthesis procedure included an in situ inverse emulsion polymerization of aniline doped with dodecylbenzene sulfonic acid (DBSA) in the presence of CNT and dissolved styrene-isoprene-styrene (SIS) block copolymer. The PANI synthesis step was carried out by applying ultrasonic energy. The dispersions obtained were processed by two methods: a recently developed precipitation-filtration procedure, and a conventional drop-cast procedure. The techniques developed resulted in homogeneous exfoliated PANI coated nanotubes within the elastomeric matrix. The presence of CNT/PANI in the SIS elastomeric matrix affects thermal, mechanical, and electrical properties of the nanocomposites. The formation of continuous three-dimensional CNT/PANI networks prepared via the precipitation-filtration method enhances the nanocomposite properties. Contrarily, the intermittent three-dimensional network prepared by conventional drop-cast method leads to inferior properties. Nanocomposites produced by both techniques are observed by HRSEM. The two processing techniques result in different structures, which affect the physical properties of the materials produced. A relatively low percolation threshold for both methods was determined. The Young's modulus of the SIS/CNT/PANI significantly increased in the presence of CNT. The precipitation-filtration technique yields an improved nanocomposite product compared to the drop-cast route. POLYM. COMPOS., 35:788-794, 2014. (c) 2013 Society of Plastics Engineers