Fabrication of organo-modified carbon nanotube with excellent heat resistance and preparation of its polymer-based nanocomposite by simple melt compounding

Crystalline polymer/single-walled carbon nanotube (SWCNT) nanocomposites were prepared using organo-modified SWCNTs with surface modification by long-chain phosphonic acid derivatives having bidentate bonds, resulting in excellent heat resistance properties. Surface modification with a long-chain phosphonate is non-desorbing, has a high desorption suppression temperature and can improve miscibility with matrix polymers by changing the other end of the functional group in various ways. In addition, since organo-SWCNTs showed amphiphilic properties when introducing a modified chain after hydrophilization, their structure and morphology could be characterized by the method of organized molecular films. The utilization of phosphonic acid derivatives containing fluorocarbon chains endowed SWCNTs with remarkable cohesive properties in phase-separable crystalline fluoropolymers to achieve polymer-based nanocomposite formation. Fluorinated SWCNTs could be easily introduced into fluoropolymers via a simple melt-compounding method. The crystalline fluoropolymer/fluorocarbon-modified SWCNT nanocomposite showed clear improvement in crystallization temperature compared with the matrix polymer. Simultaneously with the improvement in the crystallization temperature, it was confirmed that the crystallite size was increased, the lamella was thickened, the mechanical properties were improved, and the pyrolysis temperature was increased. These enhancements of the physical properties seem to be the result of the interaction between the modified-chain end and the polymer ends, and it was predicted that heterogeneous nucleation was induced by the nucleation effect. [GRAPHICS] .