The Structures And Properties Of The High Performance And Heat Vulcanization Silicone Rubber Nanocomposite

Owing to the unique-Si-O-backbone structure,silicone rubber(SR)has many superior performances,such as weather resistance,the high and low temperature resistance and so on.While the poor mechanical properties of the SR,especially the tear strength and tensile strength,can't meet the use of the industries.So it's necessary to reinforce the SR.It's the major method to use reinforced fillers and modify fillers to improve the mechanical properties of the SR.This paper mainly used the one-dimensional fillers,attapulgite(AT)and carbon nanotubes(CNTs),and zero-dimensional filler,fumed silica,to synergistically reinforce the SR,and functionalized the one-dimensional fillers to improve the dispersion and the interfacial interactions between the fillers and matrix,improving the mechanical properties and anti-crack initiation and anti-crack propagation.The detail research as following:1.The effect of the partial replacement of fumed silica by AT on the mechanical properties of the SR nanocomposites was studied.The AT and fumed silica were synergistically reinforced the SR,promoting the dispersion both of the fillers and reducing the production cost of the high performance SR nanocomposites.The results of mechanical test showed that 5 phr fumed silica replaced by 15 phr AT maintained the mechanical properties of the SR nanocomposite.2.One-dimensional nano-fillers,carbon nanotubes(CNTs),and fumed silica synergistically reinforced SR was studied.Mechanical test results showed that the tear strength,stresses at 100%and 300%of the SR nanocomposite were increased as the contents of the CNTs increased from 0,1,3 to 5 phr,but the elongation at break decreased.The reasons might be that the uneven dispersion of CNTs and the poor interfacial interaction between the CNTs and SR.The maximum tear strength of the high performance SR nanocomposite was 27.8 kN/m as the amount of the CNTs was 5 phr.3.In this paper,the CNTs were modified by tetrakis(phenylmethyl)-thioperoxydi(carbothioamide)(TBzTD)to improve the dispersion of CNTs,the interfacial interaction between the CNTs and SR,and the mechanical properties.Raman spectra and XPS measurements showed that the existence of ?-? interaction between the CNTs and the TBzTD.The vulcanization results showed that the TBzTD was grafted onto the chains of SR,indirectly linking the CNTs and the SR.The SEM and TEM tests showed that the addition of TBzTD improved the dispersion of CNTs and enhanced the interfacial interactions between the CNTs and SR.The mechanical properties measurements showed that the tear strength of the high performance SR nanocomposites increased by 114%and the elongation at break was 510%.4.The CNTs were non-covalently functionalized by 1-allyl-3-methyl imidazole chloride(AMI)to improve the dispersion of CNTs in SR,the interfacial interactions between the CNTs and SR,and the mechanical properties.Raman spectra and XPS tests showed that the existence of the cation-?/?-? interactions between AMI and CNTs.In the process of high temperature vulcanization,the AMI was grafted onto the SR chains.SEM test showed that the 0.6 phr AMI improved the dispersion of the CNTs and enhanced the interfacial interactions between the SR and CNTs.J-integration and mechanical tests showed that the tear strength of the SR nanocomposites was 51.3kN/m and the anti-crack initiation and anti-crack propagation of the SR nanocomposite was improved.