Ageing effects around the glass and melting transitions in poly(dimethylsiloxane) visualized by resistance measurements

TL;DR

This study introduces a resistance measurement method to monitor long-term ageing effects around glass and melting transitions in non-conducting rubbers, exemplified by poly(dimethylsiloxane), revealing structural changes and hysteresis.

Contribution

The paper presents a novel resistance-based technique for visualizing ageing effects in non-conducting polymers by embedding conductive particles, enabling long-term structural monitoring.

Findings

Resistance measurements reveal structural changes during ageing.

Hysteresis effects are observed around glass and melting transitions.

Method allows non-invasive, long-term monitoring of polymer ageing.

Abstract

The process of ageing in rubbers requires monitoring over long periods (days to years). To do so in non-conducting rubbers, small amounts of carbon-black particles were dispersed in a fractal network through the rubber matrix, to make the rubber conducting without modifying its properties. Continuous monitoring of the resistance reveals the structural changes around the glass and melting transitions and especially details about the hysteresis and ageing processes. We illustrate the method for the semicrystalline polymer poly(dimethylsiloxane) (PDMS).