Effect of organo-modified clay on accelerated aging resistance of hydrogenated nitrile rubber nanocomposites and their life time prediction

• Published in: Polymer degradation and stability Vol. 95; no. 12; pp. 2555 - 2562
• Main Authors: Choudhury, Anusuya, Bhowmick, Anil K., Soddemann, Matthias
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2010; Elsevier
• Subjects: Accelerated heat aging; Aging aircraft; Applied sciences; Clay (material); Composites; Degradation; Elastomers; Exact sciences and technology; Forms of application and semi-finished materials; Hydrogenated nitrile rubber; Life time prediction; Nanocomposites; Nanomaterials; Nanostructure; Nitrile rubber; Organically modified nanoclay; Polymer industry, paints, wood; Stability; Technology of polymers; Life time prediction; Hydrogenated nitrile rubber; Organically modified nanoclay; Accelerated heat aging; Organic clay; Thermal ageing; Temperature effect; Mechanical properties; Durability; Dispersion reinforced material; Experimental study; Composite material; Tensile strength; Thermal stability; Thermal properties; Vulcanizate; Artificial ageing; Nanocomposite; Exposure time
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2010.07.032

Organically modified clay – reinforced hydrogenated nitrile rubber vulcanizate was subjected to accelerated heat aging to estimate its long-term thermo-oxidative stability and its useful lifetime was compared with that of the virgin polymer for the first time. Changes in technical properties such as tensile strength, modulus and elongation at break were studied as a function of time and temperature of aging. The infrared spectroscopic analysis of the degraded products revealed that under aerobic hot aging conditions, hydrogenated nitrile rubber (HNBR) compounds undergo cross-linking reactions that lead to embrittlement and ultimately failure. Incorporation of clay filler, however, resulted in significant improvement of the degradation profile of the nanocomposite at elevated temperatures. Loss of ductility during aging of the nanocomposite was also milder, relative to the unfilled polymer, indicating a restricted degradation by the clay filled rubber, thus prolonging the durability. From the scanning electron microscopy and atomic force microscopy studies, it was found that nanofillers protected the elastomer from surface rupture that took place on oxidation. Life prediction of both virgin elastomer and the nanocomposite indicated a three-fold increase in the effective service temperature range of the HNBR using 8 parts organically modified nanoclay.