Properties Of Ground Tire Rubber Research Articles

Evaluation and Correlation Analysis of the Rheological Properties of Ground Tire Rubber and Styrene Butadiene Styrene Compound-Modified Asphalt.

With the increase in highway traffic volume, many waste tires are being produced, which puts serious pressure on the global ecological environment. Processing waste tires into powder and adding them to asphalt is an important and effective way to solve this noticeable environmental challenge. In this paper, to produce ground tire rubber (GTR) and styrene-butadiene-styrene (SBS) compound-modified asphalt, GTR was put into SBS-modified asphalt (GTRSA). Subsequently, some ordinary property tests, frequency sweep tests, and multiple stress creep recovery tests were conducted to investigate the conventional properties and rheological properties of GTRSA. Moreover, the 2S2P1D (two springs, two parabolic elements, and one dashpot) model was adopted to analyze the consequences of adding GTR content on the rheological properties of GTRSA. Finally, the Pearson correlation coefficient was employed to reveal the connection between the conventional properties and the rheological properties. The results show that GTR has a great impact on improving the rutting resistance, thermo-sensitive performance, shear resistance capability, stress sensitivity, and creep recovery performance of GTRSA. Adding 20% GTR can improve the creep recovery rate to 80.8%. The 5 °C ductility index suggests that GTR makes a difference to the low-temperature properties. The rheological properties and conventional properties had a strong linear link.

Mechanical and performance properties of re-vulcanized blends of GTR/NR

The effect of natural rubber (NR) on the mechanical and performance properties of ground tire rubber (GTR) has been investigated. The mechanical properties of vulcanized GTR/NR blends were determined in a universal testing machine. It was found a decreasing in the mechanical properties of the GTR/NR blends as the number of re-vulcanization processes increases. This behavior was attributed to the decrease in the concentration on GTR in the vulcanized GTR/NR blend with respect to the next one, and to a structural net degradation into the re-vulcanized GTR/NR blend due to the reversion process (over vulcanization). In the loss modulus charts was observed that the peaks of the curves got smaller and wide as the re-vulcanization process increased, due to the mechanical loses and elastic gains of the GTR/NR re-vulcanized blends. On the other hand, in the performance results was found that the cut growth values of Flexion Ross were more affected by the thickness of the plaque of vulcanized rubber than for the number of re-vulcanization processes of the GTR/NR blend. In addition, as the re-vulcanization processes increased, the structural degradation of the tridimensional cross-linked net, increased as well, more severely from the fourth re-vulcanization process. It could be concluded that the GTR/NR blends with high GTR content, could be used in the sole shoe fabrication, taking care that the thickness is ≤ 4.5 mm, and that the GTR/NR blends have not been subjected to more than two re-vulcanization processes.

Mechanical properties, dynamic mechanical analysis and molecular cross-linking of GTR/NR re-Vulcanized blends

The effect of natural rubber (NR) on mechanical, chemical and thermal properties of ground tire rubber (GTR) was investigated. Mechanical and thermal properties of GTR/NR vulcanized blends were determined with a universal testing machine and a dynamic mechanical analyzer (DMA). The molecular cross-linking density was determined by molecular swelling in toluene. Presents results indicate that the carbon black embedded in the GTR interior phase of the GTR/NR re-vulcanized blends, did not participate in the NR phase molecular motion restriction. The blends of GTR/NR showed the phenomenon known as reversion, leading a decreasing of the mechanical properties, that could be attributed of the degradation of the interphases (GTR/NR) n+j, j=1,2,3,…. On the other hand, the Cole-Cole charts of the GTR/NR vulcanized blends changed from a semicircular to an irregular form as the NR concentration increases, imposing the heterogeneity of the blend. In addition, in the Cole-Cole charts of GTR/NR vulcanized and re-vulcanized blends, the height ( E´´) and the width ( E´) of the curves decreased while the re-vulcanization processes number was greater; obtained results could be attributed to the increasing of the molecular cross-linking density.

Improvement of the properties of ground tire rubber (GTR)‐filled nitrile rubber vulcanizates through plasma surface modification of GTR powder

AbstractThe surface modification of ground tire rubber (GTR) powder to enhance its adhesion to nitrile rubber (NBR) vulcanizates was investigated. The hydrophobic surface of GTR powder has been transformed to a hydrophilic one through atmospheric pressure dielectric barrier discharge (DBD). The water contact angle dropped markedly from 116 to 0° after being treated for more than 10 s. Attenuated total reflectance Fourier transform infrared spectral (ATR‐FTIR) studies revealed the increase in peak intensity at 3298 and 1640 cm−1 that correspond to OH and CC, respectively, on the surface of the GTR powder. The X‐ray photoelectron spectroscopic (XPS) analysis further confirmed the presence of oxygen containing polar functional groups on the surface of the GTR powder after atmospheric plasma treatment. The improvement in tensile strength and tear strength was observed for the modified GTR‐filled NBR vulcanizates, which is attributed to the enhanced interfacial interaction between modified GTR and NBR matrix. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009