Study On The EPDM Pressure Resistance Performancep And Its Application In Butterfly Valves

EPDM has been widely used because of its excellent heat resistance,weather resistance,ozone resistance,etc.Since EPDM rubber has no polar groups in its molecular chain,EPDM rubber exhibits excellent water resistance.Often used in domestic sewage pipe fittings.Domestic sewage is mostly acidic,so the EPDM rubber used as a butterfly valve requires not only strong mechanical properties,acid-resistant medium properties,but also excellent resilience and resistance to compression set.At present,the use of domestic butterfly valves is prone to increase torque.In order to improve this problem,this paper selects EPDM(KEP980)as the research object,and studies EPDM through reinforcing system,vulcanization system and anti-aging system.The influence of processing performance,mechanical properties and dynamic mechanical properties,preparation of high performance butterfly valve materials,and prediction of their service life.Through the research results of the influence of the reinforcing system on EPDM,when the amount of carbon black was constant,the Mooney viscosity of the rubber increases with the increase of the carbon black particle size,the processing performance is improved,the Tc10 and Tc90 were increased,and the vulcanized rubber was stretched.The strength and tear strength decreased,the elongation at break continued to increase,the resilience energy increased,the compression set became larger,and the heat-resistant air aging performance did not change much.With the increase of the amount of carbon black,the processing performance of the rubber compound gradually increased.When the tensile strength of the vulcanizate increased first and then decreased,the elongation at break gradually decreased,the compression set and the resilience energy deteriorate.The elastic modulus and loss factor of the vulcanizate increased with the increase of the amount of carbon black.The use of a certain proportion of N85 filler instead of N550 found that the increase of N85 filler could reduce the Mooney viscosity of the material,improved the processing performance,and the elongation at break and the resilience could be increased without significant change in tensile strength.However,the compression set performance wasdegraded,and the elastic modulus and loss factor of the vulcanized rubber became smaller as the N85 content increases.The results of the influence of the vulcanization system on EPDM showed that the tensile strength of vulcanizate increased gradually,the compressive permanent deformation gradually increases,the elongation at break and the resilience performance changed little,and the aging resistance of heat-resistant air gradually decreased.Decreasing,the elastic modulus and loss factor of the vulcanizate increased as the amount of sulfur increases.The type of accelerator mainly had a great influence on the scorch time of the rubber compound and the positive vulcanization time of the process,and had little effect on the mechanical properties of the vulcanizate,but the EPDM compression set rate using the sulfur carrier accelerator was large.The effect of anti-aging system on EPDM showed that the antioxidant had little effect on the processing performance and mechanical properties of EPDM.The EPDM with anti-aging agent 4020 had the best heat-resistant air aging performance.The EPDM storage modulus of the anti-aging agent MB was low storage modulus,high loss modulus and high loss factor.By studying the effect of 1% HCl acidic solution on the properties of EPDM vulcanizate,the elongation at break was predicted by life,and the curve was fitted and calculated according to the evolution law of the performance,obtain a service life of2.7 years in an acidic solution at 25?.