Characterisation of the Cyclic Fatigue Performance of HNBR for use in Dynamic Rubber Seals after Ageing in High Temperatures and Organic Solvents

摘要

In many industries including the oil and gas sector,organic solvents are used extensively and come into contact with elastomeric materials.NBR and the more highly saturated HNBR are often preferred for use in these conditions due to their increased resistance to these fluids,ageing and heat resistance.Dynamic sealing applications are commonly found in the oil and gas sector.These seals are under high strain rate cyclic loading applications as well as environmental conditions such as high temperatures and contact with drilling fluids.Under all these different testing conditions,it is difficult to predict the fatigue response of these parts.As only limited research has been published on the fatigue behaviour of HNBR under these conditions,this paper examines these issues in detail.A fracture mechanics approach is a preferred method of determining an elastomers fatigue life as this enables a relationship to be determined between tearing energy and crack growth rate.Simple geometries are aged and prepared to test within loading regimes such as pure shear which enables material models to be generated and a fatigue life prediction to be made.This paper describes cyclic pure shear fatigue tests done on HNBR aged at high temperatures and in organic solvents.The tests showed an increase in tearing energies after ageing,potentially as a result of a loss of plasticiser however the cause is still under investigation.