Effects Of Non-covalent Modified CNTs On Properties Of Silicone Rubber

Silicone rubber(SR)is a kind of high performance rubbers.One of the most remarkable properties is thermal resistance.As the development of science and technology,in order to make silicone rubber fit higher temperature,the way to improve silicone rubber's thermal stability has become an inevitable subject.Carbon nanotubes(CNTs)with special structure and excellent performance,can be used as additive to improve the properties of composites,such as mechanical properties and thermal properties.In this paper,through non-covalent functionalization method,CNTs were modified by polymethylphenyl siloxane(PMPS)to produce PMPS/CNTs particles.Then CNTs-PMPS particles were blended with SR to fabricate PMPS/CNTs/SR nanocomposites.TEM,EDS,FTIR and TG Analysis were performed to demonstrate modification effects and weight gain after modification.The strength of adherence of the PMPS chains to the CNTs surface can be seen from Raman spectra.SEM showed the dispersion of CNTs in the matrix.Raman spectra and DMA of SR based nanocomposites were taken to detect the interfacial interaction between CNTs and the matrix.Furthermore,mechanical properties before and after thermal aging of composites and TG Analysis have been studied,in order to discuss the influence of different surface states of CNTs on the mechanical properties and thermal stability of SR composites.The results indicated that PMPS was adsorbed on surface of CNTs through ?-? interaction and hydrophobic interaction,creating adsorption layer to impede the aggregation of nanotubes.After modification by definite amount of PMPS,CNTs were dispersed in ethanol without settlement for six month.Dispersation of PMPS/CNTs in SR matrix was improved as well,and monodispersed CNTs could be observed.What's more,the interfacial interaction between CNTs and matrix was improved.Mechanical properties of PMPS/CNTs/SR nanocomposites were enhanced.Compared with CNTs/SR nanocomposite,the tensile strength and elongation at break of PMPS-2/CNTs/SR nanocomposite were improved by 62 % and 48 % after thermal aging,respectively.These proved that thermal stability of SR composites was improved.Meanwhile,TG results indicated that compared with CNTs,PMPS/CNTs could slightly improve initial degradation temperature of SR based nanocomposites.