| Methyl vinyl silicone rubber(MVQ)has the advantages of good high and low temperature resistance,weather resistance and low compression set rate.It plays a great role in oil seals,rubber hoses and other parts.However,the non-polar oil resistance of silicone rubber is poor.How to improve the oil resistance of silicone rubber under high temperature is of great significance.Taking MVQ as the research object,this paper explores the blending ratio of low vinyl silicone rubber and high vinyl silicone rubber,the type and amount of coupling agent,the type and amount of metal oxide and fluorine powder,and the influence of diatomite particle size and amount on the properties of silicone rubber.Firstly,the effects of the blending ratio of low vinyl silicone rubber,high vinyl silicone rubber and the type of coupling agent on the properties of silicone rubber were studied.The results showed that with the increase of the amount of high vinyl silicone rubber,the static mechanical properties of silicone rubber decreased at room temperature,the compression set rate decreased gradually,the heat-resistant air aging property changed little,and the oil resistance of IRM903 improved gradually;Compared with the other four coupling agents,the silicone rubber reinforced by A171 modified silica has slightly lower static mechanical properties,the best compression set performance and the best resistance to IRM903.Secondly,the effects of the types of fluorine micro powder and the amount of PFA fluorine micro powder on the properties of silicone rubber were studied.The results showed that when three kinds of fluorine micro powder were added respectively,the vulcanization efficiency of silicone rubber increased slightly,the tensile strength decreased slightly,the heat-resistant air aging performance changed little,the increase of compression set rate of PFA fluorine micro powder on silicone rubber was the smallest,and the mass change rate and volume change rate after soaking in IRM903 oil were the smallest.Comprehensive comparison,The comprehensive properties of silicone rubber with PFA fluorine micro powder are better;With the increase of the amount of PFA fluorine powder,the static mechanical properties of silicone rubber tend to decrease,the compression permanent deformation rate and heat-resistant air aging properties of silicone rubber change little,and the resistance of silicone rubber to IRM903 oil is significantly improved.When the amount of PFA powder is 30-40 phr,the resistance of silicone rubber to IRM903 oil is better.Then the effects of the types of metal oxides and the amount of Mg O on the properties of silicone rubber were studied.The results showed that the types of metal oxides had little effect on the mechanical properties and heat-resistant air aging properties of silicone rubber.The vulcanization efficiency of silicone rubber added with Mg O was the highest,the compression set rate was the lowest,which was 6%,and the resistance to IRM903 was better.In a comprehensive comparison,the comprehensive properties of silicone rubber added with Mg O were better;With the increase of Mg O dosage,the vulcanization time of silicone rubber is shortened,the static mechanical properties are gradually reduced,the heat-resistant air aging performance and oil resistance to IRM903 can be gradually improved,and the compression set rate first decreases and then increases with the increase of Mg O dosage,and it is the lowest when the dosage of Mg O is 10 phr.In a comprehensive comparison,the comprehensive properties of silicone rubber are better when the dosage of Mg O is 10 phr.Finally,the effects of diatomite particle size,dosage and A151 dosage on the properties of silicone rubber were studied.The results showed that after adding unmodified diatomite,the static mechanical properties of silicone rubber decreased and the compression set rate decreased significantly.With the decrease of diatomite particle size,the static mechanical properties of silicone rubber tended to improve,the oil resistance of IRM903 decreased slightly,and the compression set performance and heat-resistant air aging performance changed little,By comprehensive comparison,the particle size is 18?m diatomite,the comprehensive properties of silicone rubber are better;With the increase of the amount of modified diatomite,the static mechanical properties of silicone rubber were slightly improved,the compression set rate and heat-resistant air aging properties changed little,and the resistance to IRM903 was significantly improved.When the amount of diatomite was 50 phr,the comprehensive properties of silicone rubber were better;After adding A151,the static mechanical properties and heat-resistant air aging properties of silicone rubber were improved,but changed little with the increase of A151 dosage,the compression set rate increased gradually with the increase of A151 dosage,and the oil resistance of silicone rubber IRM903 improved gradually with the increase of A151 dosage;Comprehensive comparison shows that when the dosage of A151 is 2 phr,the comprehensive properties of silicone rubber are better. |
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