Preparation And Characterization Of Surface-modified Carbon Nanotubes/phenyl Silicone Rubber Composites

Silicon rubber(SR)has excellent thermal stability and is applied widely in the field of energy,power,aerospace and other high temperature fields.Phenyl silicone rubber(PhSR)containing a certain amount of phenyl in side groups has more outstanding thermal stability,making its scientific research and industrial application prospects more broad.Carbon nanotubes(CNTs),which have a unique structure and excellent performances,are widely used to prepare composite materials.In recent years,the mechanical,electrical and thermal properties of CNTs/SR composites have been studied more and more widely.However,there are few reports on the study of CNTs/ PhSR.In this paper,?,?-dihydroxy polydimethylsiloxane(HPDMS)was grafted to CNTs-COOH and the modified CNTs was added to PhSR.The effects of modification on the mechanical and thermal properties of CNTs/PhSR composites were studied by means of SEM,universal tensile machine,thermogravimetric analyses(TGA)and TG-FTIR.The results showed that HPDMS modification could effectively enhance the dispersion of CNTs in various solvents;the dispersion of CNTs-HPDMS in matrix as well as the interfacial interaction was also improved significantly;compared to CNTs-COOH,CNTs-HPDMS could more largely enhance the mechanical properties and thermal stability of SR both in anaerobic and aerobic environment,and for example,compared to blank PhSR,the tensile strength of CNTs-COOH/PhSR was increased by 42%,while that of CNTs-HPDMS/PhSR was increased by 123%;besides,the initial degradation temperature of CNTs-HPDMS/Ph SR both in anaerobic and aerobic environment were about 15 °C higher than those of CNTs-COOH/Ph SR;the results of TG-FTIR showed that the better dispersion of CNTs-HPDMS made it more effective to play the role of barrier and thermal conductivity.The oxidation reaction was almost completely inhibited in CNTs-HPDMS/PhSR,and the amount of oxidation products was decreased by 73.5%.