Stusy On Aging Behavior And Performance Prediction Of NBR-based Blends

The paper mainly studies the variation of aging behavior(hot air aging and hot oil aging)of blended rubber after NBR combined with BR,CR,EPDM and AEM,and the performance of the elongation at break and the tensile stress of the blended rubber under hot air aging behavior were predicted.It is predicted that the performance of the blended rubber changes under certain conditions,which has certain guiding significance for the further application of the blended rubber.(1)The hot air aging behavior of NBR/BR blends was studied.The performance of blended rubber was slightly lower than that of NBR,but the rate of change of properties was low and the low temperature resistance was improved.The properties of blended rubbers were predicted.It is found that the service life of NBR/BR blends is slightly lower than that of NBR when the same aging degree is reached under the same aging conditions at 25 °C.(2)The effects of different vulcanization systems on the properties of NBR/CR blends were studied.It was found that the blends of sulfur vulcanization system and sulfur carrier vulcanization system had the best performance when the combined ratio was 70/30,but under the sulfur vulcanization system.The performance of the blended rubber is better.The aging behavior of the blended rubber in the sulfur vulcanization system shows that the performance of the blended rubber changes rapidly at the initial stage of aging,and the performance change tends to be stable in the late aging period;The hot air aging performance of the blended rubber is predicted.When the same aging process is experienced,the service life of the blended rubber is greater than the service life of the NBR,and the hot air performance is improved.(3)The effect of vulcanization time on the properties of the blended rubber was studied when the vulcanization speed of NBR and EPDM was very different(the speed of NBR vulcanization was fast and the curing speed of EPDM was slow).It was found that the vulcanization time had a great influence on the properties of the blended rubber and the curing time was short.The performance of the blended rubber is poor and the rate of change is large,and the change of the properties of the blended rubber is mainly caused by the change of the EPDM phase in the blended rubber(the degree of vulcanization of the EPDM phase in the blended rubber is low);the hot air aging behavior of the blended rubber The study found that the blending rubber with short curing time has a large rate of change in performance at the initial stage of aging,and the change is slow in the later stage.(4)The properties of the blended rubber were studied under the matching conditions of NBR and EPDM vulcanization rate.It was found that the performance of the blended rubber was much greater than that of the blended rubber with a large difference between the NBR and EPDM vulcanization speeds.The performance prediction shows that the service life of the blended rubber is much longer than that of the NBR when the same degree of aging is achieved,indicating that the heat-resistant air properties of the blended rubber are significantly improved.(5)The effect of vulcanization system on the properties of NBR/AEM blending rubber was studied.It was found that the air-resistance of the blended rubber under the ordinary sulfur vulcanization system was the worst,and the heat-resistant air aging performance of the blended rubber under the sulfur carrier vulcanization system was basically the same.And the performance of the blending gel under the peroxide vulcanization system is low,but the rate of change is small.It is known that the hot air aging performance of the blended rubber predicts that the blended rubber of the ordinary sulfur vulcanization system has a longer service life at normal temperature,and the service life of the blended rubber of the sulfur carrier vulcanization system is better when the temperature is higher.