Lifetime prediction of nitrile rubber by a sensitive in-situ stability evaluation method

摘要

Nitrile rubber is widely used in automobile and petroleum industries as seals because of its perfect oil and abrasion resistance. But with unsaturated bonds in backbone, it is easy to be oxidized and crosslink further under service condition (high temperature, with stress and contacting oil) and lose the elasticity. This process is often accelerated by the migration of antioxidants and plasticizers. A sensitive in-situ stability evaluation method was developed based on high sensitivity FTIR. Volatiles attributed to curing agents, antioxidants, plasticizers and their derivatives in unaged and aged nitrile rubber were detected. The volatile content has perfect correspondence to the aging status of nitrile rubbers. Therefore, it is a powerful method for the lifetime prediction. It is also worth noting that the evaluation costs only several hours and is quite sensitive to even very early aging. Compared to general accelerated aging procedure, which often costs several months or even years, this new method is quite efficient and promising for stability evaluation and lifetime prediction.