On the temperature dependence of the cyclic compression behaviour of a thermoplastic vulcanizate elastomer

• Published in: Polymer testing 2022-08, Vol.112, p.107650, Article 107650
• Main Authors: Persson, Anna-Maria M.R., Hinrichsen, Einar L., Andreassen, Erik
• Format: Article
• Language: English
• Subjects: Bulk modulus; Compression set; Hysteresis loss; Mullins effect; Poisson's ratio; Thermoplastic elastomer
• ISSN: 0142-9418; 1873-2348
• DOI: 10.1016/j.polymertesting.2022.107650

Effects of temperature on the uniaxial cyclic compression of a polypropylene based thermoplastic vulcanizate were studied in the range −40 °C–100 °C. The effect of temperature on the stress level was similar to that on the storage modulus from dynamic mechanical analysis. The residual strain after a cycle increased with decreasing temperature below 23 °C, while from 23 °C to 100 °C the effect of temperature was small. Both dependencies were correlated with the effect of temperature on the fraction of stress relaxed in the cycle. The residual strain after a cycle and the standard compression set (ISO 815–1, method A) had different temperature dependencies, and this was rationalized based on the different timescales of the tests and the different temperatures during loading and unloading. Two different methods for determining the Poisson's ratio in this temperature range were investigated in terms of measurement accuracy. The preferred method was based on input from dynamic mechanical analysis and triaxial compression. •Effects of temperature and cycle number on the cyclic compressive loading of a TPE.•Effects of temperature in a wide range, −40 °C–100 °C.•Residual strains in cyclic tests compared to standard compression set values.•Effects of temperature on bulk modulus and Poisson's ratio.