Study on the oxidative induction test applied to medical polymers

Abstract

This article continues our study published earlier on the application of the oxidative induction test to a wide variety of medical polymers.

In a series of thermoplastic olefin elastomers (TPO), the extrapolated induction time on the Arrhenius plot was found to coincide with published results based on oven aging mechanical studies extending to much lower temperatures and times as long as nearly a year. This agreement indicates the potential of the OIT for long term durability prediction.

For medical flexible PVC compounds, the traditional measure of extent of degradation by color formation was found to correlate to measured oxidative induction times. Furthermore, three distinct regimes were also detected, where in the first phase, little color changes can be detected.

In a longer time, lower temperature study, effect of room temperature fluctuations was clearly detected, emphasizing the need for good environmental control for sensitive detections. These and other recent results will be presented to illustrate the utility of this versatile test.