Thermomechanical and Energetic Behavior of Elastomers Investigated with IR Thermography-Based Surface Calorimetry: Revisiting Rubber Elasticity, Viscosity, Stress Softening, Strain-Induced Crystallization, and Energy Stored

This chapter discusses the use of the surface calorimetry approach to study rubber deformation. It introduces the theoretical framework for determining heat source (or heat power density) from full temperature field measurements and the heat diffusion equation. The determination of the mean intrinsic dissipation and the strain-induced crystallinity from the heat sources is presented and discussed. Typical results obtained under homogeneous tensile loadings are reviewed and analyzed according to four types of calorimetric responses. The types of responses depend on whether the rubber is filled or not, and whether it is crystallizing or not. The calorimetric signatures of thermo-elasticity, viscosity, strain-induced crystallization, stress softening, and energy storage are analyzed and discussed.