scholarly journals The Impact of Ground Tire Rubber Oxidation with H2O2 and KMnO4 on the Structure and Performance of Flexible Polyurethane/Ground Tire Rubber Composite Foams

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 499
Author(s):  
Aleksander Hejna ◽  
Adam Olszewski ◽  
Łukasz Zedler ◽  
Paulina Kosmela ◽  
Krzysztof Formela

The use of waste tires is a very critical issue, considering their environmental and economic implications. One of the simplest and the least harmful methods is conversion of tires into ground tire rubber (GTR), which can be introduced into different polymer matrices as a filler. However, these applications often require proper modifications to provide compatibility with the polymer matrix. In this study, we examined the impact of GTR oxidation with hydrogen peroxide and potassium permanganate on the processing and properties of flexible polyurethane/GTR composite foams. Applied treatments caused oxidation and introduction of hydroxyl groups onto the surface of rubber particles, expressed by the broad range of their hydroxyl numbers. It resulted in noticeable differences in the processing of the polyurethane system and affected the structure of flexible composite foams. Treatment with H2O2 resulted in a 31% rise of apparent density, while the catalytic activity of potassium ions enhanced foaming of system decreased density by 25% and increased the open cell content. Better mechanical performance was noted for H2O2 modifications (even by 100% higher normalized compressive strength), because of the voids in cell walls and incompletely developed structure during polymerization, accelerated by KMnO4 treatment. This paper shows that modification of ground tire rubber is a very promising approach, and when properly performed may be applied to engineer the structure and performance of polyurethane composite foams.

2021 ◽  
Vol 5 (3) ◽  
pp. 90
Author(s):  
Paulina Kosmela ◽  
Adam Olszewski ◽  
Łukasz Zedler ◽  
Paulina Burger ◽  
Krzysztof Formela ◽  
...  

The utilization of post-consumer car tires is an essential issue from an ecological and economic point of view. One of the simplest and the least harmful methods is their material recycling resulting in ground tire rubber (GTR), which can be further applied as fillers for polymer-based composites. Nevertheless, insufficient interfacial interactions implicate the necessity of GTR modification before introduction into polymer matrices. In this study, we investigated the influence of rapeseed oil-assisted thermo-mechanical treatment of GTR using a reactive extrusion process on the processing, structure, and performance of flexible polyurethane/GTR composite foams. Applied modifications affected the processing of polyurethane systems. They caused a noticeable reduction in the average cell size of foams, which was attributed to the potential nucleating activity of solid particles and changes in surface tension caused by the presence of oil. Such an effect was especially pronounced for the waste rapeseed oil, which resulted in the highest content of closed cells. Structural changes caused by GTR modification implicated the enhancement of foams’ strength. Mechanical performance was significantly affected by the applied modifications due to the changes in glass transition temperature. Moreover, the incorporation of waste GTR particles into the polyurethane matrix noticeably improved its thermal stability.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3807
Author(s):  
Paulina Kosmela ◽  
Adam Olszewski ◽  
Łukasz Zedler ◽  
Paulina Burger ◽  
Adam Piasecki ◽  
...  

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.


2015 ◽  
Vol 34 (9) ◽  
pp. 708-717 ◽  
Author(s):  
Łukasz Piszczyk ◽  
Aleksander Hejna ◽  
Magdalena Danowska ◽  
Michał Strankowski ◽  
Krzysztof Formela

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2090 ◽  
Author(s):  
Łukasz Zedler ◽  
Daria Kowalkowska-Zedler ◽  
Henri Vahabi ◽  
Mohammad Reza Saeb ◽  
Xavier Colom ◽  
...  

Ground tire rubber (GTR) was processed using an auto-thermal extrusion as a prerequisite to green reclaiming of waste rubbers. The reclaimed GTR underwent a series of tests: thermogravimetric analysis combined with Fourier-transform infrared spectroscopy (TGA-FTIR), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and static headspace and gas chromatography-mass spectrometry (SHS-GC-MS) in order to evaluate the impact of barrel heating conditions (with/without external barrel heating) on the reclaiming process of GTR. Moreover, samples were cured to assess the impact of reclaiming heating conditions on curing characteristics and physico-mechanical properties. Detailed analysis of the results indicated that the application of auto-thermal extrusion is a promising approach for the sustainable development of reclaiming technologies.


2014 ◽  
Vol 24 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Łukasz Piszczyk ◽  
Aleksander Hejna ◽  
Krzysztof Formela ◽  
Magdalena Danowska ◽  
Michał Strankowski

2017 ◽  
Vol 108 ◽  
pp. 844-852 ◽  
Author(s):  
Krzysztof Formela ◽  
Aleksander Hejna ◽  
Łukasz Zedler ◽  
Marta Przybysz ◽  
Jacek Ryl ◽  
...  

2019 ◽  
Vol 11 (6) ◽  
pp. 1792 ◽  
Author(s):  
Punyaslok Rath ◽  
Joshua Love ◽  
William Buttlar ◽  
Henrique Reis

The usage of Ground Tire Rubber (GTR) in asphalt pavements has gained renewed interest due to its potential sustainability, economic, and performance benefits. This study focuses on asphalt mixtures designed with three different rubber modifier products including (1) a terminal-blend GTR, (2) a dry-process, chemically processed rubber product, and (3) a terminal-blend rubber-polymer hybrid product. The modifications were incorporated into Illinois Tollway’s approved Stone Matrix Asphalt (SMA) designs using (1) a base binder (PG 58-28), (2) a softer binder (PG 46-34), and (3) a softer binder with higher recycled content. Disk-shaped Compact Tension (DC(T)) test, Hamburg Wheel Tracking Test (HWTT) and Acoustic Emission (AE) tests were performed to characterize the mixtures. The fracture energy for most mixtures met the stringent criteria of 690 J/m2 and the rut depths measured were less than 6 mm at 20,000 wheel passes. A Hamburg-DC(T) plot suggests that higher amounts of RAP/RAS (RAP: Reclaimed Asphalt Pavement; RAS: Reusable Asphalt Shingles) can be successfully used if a suitably soft base binder is employed.


2013 ◽  
Vol 315 ◽  
pp. 861-866 ◽  
Author(s):  
S. Kanna Subramaniyan ◽  
Shahruddin Mahzan ◽  
Mohd Imran bin Ghazali ◽  
Maznan Ismon ◽  
Ahmad Mujahid Ahmad Zaidi

In the present work polyurethane foams containing various content loadings of kenaf fiber and recycled tire rubber particulates were prepared and studied, with the objective of developing alternative composite rigid foams. The influence of the filler content on the foam microstructure and its physical and mechanical behavior has been studied for three different polyurethane resin densities. Microstructural observation on fracture surface of composites was carried out using scanning electron microscopy. It has shown closed spherical cells with reduced size when the fillers are added. Nevertheless, the incorporation of kenaf fiber and recycled tire rubber particulates that refined at 80 mesh led to higher mechanical properties than that unfilled polyurethane foam. A 6% filler content loading exhibited the optimum compression stress and compression modulus, while further increase of filler content loading resulted in decline in mechanical behavior. The presence of larger filler content deteriorated the polyurethane system cellular structure and lead to poor composites strength. Overall, the use of kenaf fiber and recycled tire rubber particulates gives composite foams with comparable mechanical behavior for the studied filler reinforcement level.


2021 ◽  
Vol 22 (9) ◽  
pp. 4757
Author(s):  
Karolina Miedzińska ◽  
Sylwia Członka ◽  
Anna Strąkowska ◽  
Krzysztof Strzelec

In the following study, ground plum stones and silanized ground plum stones were used as natural fillers for novel polyurethane (PUR) composite foams. The impact of 1, 2, and 5 wt.% of fillers on the cellular structure, foaming parameters, and mechanical, thermomechanical, and thermal properties of produced foams were assessed. The results showed that the silanization process leads to acquiring fillers with a smoother surface compared to unmodified filler. The results also showed that the morphology of the obtained materials is affected by the type and content of filler. Moreover, the modified PUR foams showed improved properties. For example, compared with the reference foam (PUR_REF), the foam with the addition of 1 wt.% of unmodified plum filler showed better mechanical properties, such as higher compressive strength (~8% improvement) and better flexural strength (~6% improvement). The addition of silanized plum filler improved the thermal stability and hydrophobic character of PUR foams. This work shows the relationship between the mechanical, thermal, and application properties of the obtained PUR composites depending on the modification of the filler used during synthesis.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4709 ◽  
Author(s):  
Sylwia Członka ◽  
Anna Strąkowska ◽  
Agnė Kairytė

Polyurethane (PUR) foams reinforced with 2 wt.% hemp shives (HS) fillers were successfully synthesized. Three different types of HS fillers were evaluated—non-treated HS, HS impregnated with sunflower oil (SO) and HS impregnated with tung oil (TO). The impact of each type of HS fillers on cellular morphology, mechanical performances, thermal stability, and flame retardancy was evaluated. It has been shown that the addition of HS fillers improved the mechanical characteristics of PUR foams. Among all modified series, the greatest improvement was observed after the incorporation of non-treated HS filler—when compared with neat foams, the value of compressive strength increased by ~13%. Moreover, the incorporation of impregnated HS fillers resulted in the improvement of thermal stability and flame retardancy of PUR foams. For example, the addition of both types of impregnated HS fillers significantly decreased the value of heat peak release (pHRR), total smoke release (TSR), and limiting oxygen index (LOI). Moreover, the PUR foams containing impregnated fillers were characterized by improved hydrophobicity and limited water uptake. The obtained results confirmed that the modification of PUR foams with non-treated and impregnated HS fillers may be a successful approach in producing polymeric composites with improved properties.


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