Heat Build‐Up of Rubber in Different Deformation Modes and Its Correlation to Viscoelasticity

Heat build-up (HBU) under deformation is a critical characteristic of rubber materials, and it significantly influences the performance and service safety of final products. In addition, the deformation modes of materials can vary considerably depending on the product and working conditions, resulting in a complex and sometimes unpredictable correlation between HBU and the viscoelasticity of materials. In this study, strain- and stress-controlled HBU experiments on rubber composites are conducted using a dynamic mechanical analyzer (DMA) equipped with a sample temperature measuring unit. During the HBU tests, dynamic mechanical properties are monitored simultaneously with HBU, ensuring a direct correlation between viscoelasticity and heat generation. The energy density of dissipation, W_diss in the stress-strain hysteresis loop, is considered to be the source of heat generation and can be expressed through various rheological parameters. It is found that, in strain-controlled mode, the HBU of tested materials correlates linearly with the loss modulus, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics><mml:msup><mml:mi>E</mml:mi> <mml:mrow><mml:mo>'</mml:mo> <mml:mo>'</mml:mo></mml:mrow> </mml:msup> <mml:annotation>$E^{\prime\prime}$</mml:annotation></mml:semantics> </mml:math> . In contrast, in stress-controlled mode, the HBU correlates linearly with the combined formats of rheological parameters, such as <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics><mml:mrow><mml:mi>t</mml:mi> <mml:mi>a</mml:mi> <mml:mi>n</mml:mi> <mml:mi>δ</mml:mi> <mml:mo>/</mml:mo> <mml:msup><mml:mi>E</mml:mi> <mml:mo>'</mml:mo></mml:msup> </mml:mrow> <mml:annotation>$tan\delta /E^{\prime}$</mml:annotation></mml:semantics> </mml:math> . These results suggest a new guideline for applying viscoelastic parameters, or their combinations, as evaluation indicators for the performance of rubber materials based on their working conditions.