Mooney-Rivlin Parameter Determination Model as a Function of Temperature in Vulcanized Rubber Based on Molecular...

Area of Science:

• Materials Science
• Polymer Physics
• Computational Mechanics

Background:

• The automotive industry requires high-quality, environmentally friendly products developed rapidly.
• Manufacturing processes critically impact the long-term performance of components like door grommets.
• Understanding polymer behavior under stress is essential for material selection and design.

Purpose of the Study:

• To investigate the influence of crosslink density and temperature on ethylene-propylene-diene monomer (EPDM) mechanical properties.
• To validate molecular dynamics (MD) simulation results with experimental data.
• To develop predictive models for EPDM stress-strain behavior.

Main Methods:

• Uniaxial tensile tests using molecular dynamics (MD) simulations.
• Application of the Mooney-Rivlin (MR) model to fit MD simulation data.
• Development of an exponential-type model for temperature-dependent parameters C1(T) and C2(T).
• Experimental validation through hardness tests (ASTM 1415-88).

Main Results:

• Crosslink density and free volume fraction significantly impact EPDM stiffness in a deformed state.
• MD simulation results, when superimposed onto the MR model, accurately predict macroscopic mechanical behavior.
• The proposed exponential model effectively calculates temperature-dependent parameters for the MR model.
• Experimental hardness tests confirmed the simulation findings.

Conclusions:

• Molecular dynamics simulations provide accurate characterization of EPDM stress-strain behavior at the molecular level.
• The study offers valuable insights for the application of EPDM in injection molding processes.
• This research contributes to the development of advanced rubber materials for the automotive sector.