Thermomechanical analysis of polypropylene in tensile tests

Polypropylene (PP) is a semi-crystalline thermoplastic polymer that is often used to make automotive parts, packaging for consumer products and medical components, among others. The present paper focuses on the analysis of the thermomechanical behaviour of PP specimens in monotonic tensile tests at different strain rates and variable temperatures. The thermal properties-specific heat, glass transition temperature, coefficient of thermal expansion, thermal conductivity-are obtained experimentally. Tensile tests were performed at different strain rates (0.000083 s(-1), 0.00083 s(-1), 0.0083 s(-1) and 0.083 s(-1)) and temperatures (25 degrees C, 40 degrees C, 60 degrees C and 80 degrees C). Based on these experiments, it is proposed the modelling of the mechanical behaviour. The model allows to estimate the stress vs strain curve for any strain rate between 0.000083s(-1) and 0.083s(-1) and any temperature between 25(?)C and 80(?)C from only four tensile tests performed at two different test temperatures and two different strain rates. The model predictions have reasonably good accuracy under all the conditions tested.

Automated summary

This paper focuses on the analysis of the thermomechanical behavior of polypropylene (PP) in different strain rates and temperatures. The thermal properties of PP are experimentally obtained and a mechanical behavior model is proposed based on the experimental results. The model predicts the stress-strain curve for different strain rates and temperatures with reasonably good accuracy.