Preparation And Properties Of Silicone Rubber Ionomer

As a polymer material with excellent properties,silicone rubber has the advantages of simple preparation process and convenient use.It has important applications in various fields such as national defense construction and national economy,and has attracted more and more attention from scientific researchers.However,unmodified silicone rubber has poor mechanical properties,which limits the expansion of its application range.In this paper,three different modified crosslinking agents were synthesized from citrate and Aminopropyltriethoxysilane(APTES),and the corresponding silicone rubber ionomers were prepared.The ionic groups in the silicone rubber ionomer have dipole interactions,which can form a physical cross-linked structure,increase the intermolecular force of the silicone rubber,and improve its mechanical properties.The specific research content is as follows:(1)The modified crosslinker MCA was synthesized by the amidation reaction of monosodium citrate and APTES.The silicone rubber ionomer MCA-SIR was prepared with MCA as the crosslinking agent,and the ionic groups were introduced into the silicone rubber.The silicone rubber ionomer MCA-SIR was tested by surface element distribution(EDS),thermal weight loss(TG),crosslink density,mechanical properties and other characterization methods.The results showed that:The thermal stability and mechanical properties of silicone rubber ionomer are significantly improved.Compared with silicone rubber matrix APTES-3-SR,the tensile strength and elongation at break of MCA-3-SIR are increased by 30.4%and 131.1%,respectively,and the maximum degradation rate temperature increased by 75?.(2)Modified crosslinking agents MBA and DCA with different ionic group contents were synthesized from monosodium citrate and disodium citrate,respectively,and silicone rubber ionomers MBA-SIR and DCA-SIR were prepared.The effect of ionic group content on silicone rubber properties was further studied.The results show that the introduction of ionic groups can improve the mechanical properties and thermal stability of silicone rubber,but too high content of ionic groups will lead to the aggregation of ionic groups and modified crosslinkers,which will reduce the properties of silicone rubber.the result shows:the introduction of ionic groups can increase the cross-linking density of silicone rubber,improve the mechanical properties and thermal stability of silicone rubber,but too high content of ionic groups will cause the agglomeration of ionic groups and modified cross-linking agent,which reduces its performance;The silicon rubber ionomer DCA-3-SIR has the best performance,the tensile strength and elongation at break are 0.48MPa and 537.2%,respectively,which are 109%and 116%higher than those of silicone rubber matrix APTES-3-SR,and the maximum degradation rate temperature is increased by 80? to 545?.