Ground Tire Rubber Filled Flexible Polyurethane Foam-Effect of Waste Rubber Treatment on Composite Performance.

Paulina Kosmela,Aleksander Hejna,Krzysztof Formela,Paulina Burger,Adam Piasecki,Łukasz Zedler,Adam Olszewski

doi:10.3390/ma14143807

Paulina Kosmela, Aleksander Hejna + Show 5 more

Open Access

https://doi.org/10.3390/ma14143807

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Abstract

The application range of flexible polyurethane (PU) foams is comprehensive because of their versatility and flexibility in adjusting structure and performance. In addition to the investigations associated with further broadening of their potential properties, researchers are looking for new raw materials, beneficially originated from renewable resources or recycling. A great example of such a material is ground tire rubber (GTR)—the product of the material recycling of post-consumer car tires. To fully exploit the benefits of this material, it should be modified to enhance the interfacial interactions between PU and GTR. In the presented work, GTR particles were thermo-mechanically modified with the addition of fresh and waste rapeseed oil in the reactive extrusion process. The introduction of modified GTR particles into a flexible PU matrix caused a beneficial 17–28% decrease in average cell diameters. Such an effect caused an even 5% drop in thermal conductivity coefficient values, enhancing thermal insulation performance. The application of waste oil resulted in the superior mechanical performance of composites compared to the fresh one and thermo-mechanical modification without oils. The compressive and tensile performance of composites filled with waste oil-modified GTR was almost the same as for the unfilled foam. Moreover, the introduction of ground tire rubber particles enhanced the thermal stability of neat polyurethane foam.

Highlights

Polyurethanes (PU) are very versatile materials with a broad range of potential industrial applications
Formela et al [16] proved that even the short treatment of ground tire rubber (GTR) in the extruder can result in an appearance of hydroxyl groups on the surface of analyzed waste material
The presented paper aimed to analyze the influence of the thermo-mechanical treatment of ground tire rubber particles on the structure and performance of foamed PU/GTR

Summary

Introduction

Polyurethanes (PU) are very versatile materials with a broad range of potential industrial applications. Literature data indicate that it may beneficially affect the compressive strength and the damping properties considering the mechanical and acoustic vibrations [19] Such effects play a vital role in the applications of PU foams in packaging, automotive, and construction industries or as soundproofing materials [20]. The X-ray photoelectron spectral analysis indicated the 3.4% increase of the oxygen content, indicating partial oxidation of the GTR surface Such an effect was beneficial for the foams’ cellular structure and enabled reduction of the average cell diameter, pointing to the enhanced interfacial interactions with polyurethane matrix. Keeping in mind the potentials benefits of the GTR introduction into a foamed flexible polyurethane matrix, we investigated the application of this waste as a filler in the presented work. Oxidation of oils occurring during primary use can be confirmed by the significantly higher peroxide values

Modifications of Ground Tire Rubber

Characterization Techniques

Results and Discussion

Temperature

Conclusions