Accelerated Life Prediction of Automotive Elastomers using Thermo-Gravimetric Analysis

Abstract

Polymers find their use in a variety of products and their share in a particular application like automobile components such as gaskets, O-ring, Sealing, Hoses, Fuel line, Fuel filter necks, float, etc. in vehicle fuel system is increasing day by day. In some applications a component made from polymer is subjected to elevated temperatures for prolonged durations and are prone to failure due to thermal stresses. Therefore, understanding of failure mechanism is important to predict the life of polymer particularly in cases of critical applications and where it is used for longer durations. The Arrhenius equation is utilized for prediction of assessment of life of polymers through due to of the impact of temperature over time. Lifetime predictions are conventionally made by exposing sample polymers to various temperatures for prolonged duration with periodic measurement of desired properties, which is a very time-consuming process. In present research, two materials viz., FKM and PVC/NBR blend were analyzed using thermo-gravimetric assessment to simulate failure utilizing the decomposition behavior caused by thermal effects. The thermo-gravimetric analysis was performed at various heating rates of 5 to 25 °C/min. The rate of change of thermal decomposition of FKM and PVC/NBR blend were evaluated using Arrhenius equation. Different weight-loss percentages (5%, 10% and 20%) during TGA were considered as failure criterion. Activation energy (E) was calculated and thermal life of was predicted for both the materials. This study provided a quick method with considerable reduction in efforts, cost and time for prediction of life of polymers by using kinetics parameters derived from experiments conducted at higher temperatures.