GTR/Thermoplastics Blends: How Do Interfacial Interactions Govern Processing and Physico-Mechanical Properties?

Area of Science:

• Materials Science
• Polymer Science
• Rubber Technology

Background:

• Ground tire rubber (GTR) is a recycled material with potential applications in polymer blends.
• Thermoplastic modifiers can alter the properties and processability of rubber materials.

Purpose of the Study:

• To investigate the microstructure and processing-performance property interrelationships of GTR/thermoplastic blends.
• To evaluate the effect of different thermoplastic modifiers (TOR, EVA, EOC, LLDPE) on GTR blends.
• To determine the influence of GTR/thermoplastic ratio on blend characteristics.

Main Methods:

• Melt-compounding of GTR/thermoplastic blends (50/50 and 75/25 wt.%).
• Characterization using AFM, SEM, RPA, Mooney viscometer, DSC, tensile tests, and swelling behavior.
• Analysis of microstructure, processing behavior, and physico-mechanical properties.

Main Results:

• Thermoplastic type significantly influenced processing behavior and microstructure in GTR-rich blends.
• GTR/thermoplastic ratio affected elongation at break, hardness, and density, but not tensile strength.
• DSC indicated thermoplastics act as binders, not plasticizers, with near-constant glass-transition temperatures.
• RPA showed higher viscoelastic moduli (G*, η*) in GTR-rich blends.
• SEM and AFM confirmed rubber-like interfacial breaks and contact between GTR and thermoplastics.

Conclusions:

• Thermoplastic modifiers play a crucial role in tailoring the properties of GTR blends.
• The investigated thermoplastics function as binders, enhancing the structural integrity of GTR composites.
• Understanding these interrelationships is key for developing advanced GTR-based materials.