scholarly journals Rheological properties of a reclaimed waste tire rubber through high-pressure high-temperature sintering

Author(s):  
Ubaidillah ◽  
N. A. Yunus ◽  
S. A. A. Aziz ◽  
N. A. A. Wahab ◽  
S. A. Mazlan
2021 ◽  
Author(s):  
Kui Hu ◽  
Caihua Yu ◽  
Yujing Chen ◽  
Wei Li ◽  
Chen Guixiang ◽  
...  

Abstract The recycling of crumbled waste tire rubber (CWTB) is a major environmental problem facing mankind, and the incorporation of CWTB as a modifier into asphalt is an extremely promising approach. However, the modification mechanism of CWTB to asphalt is not well understood, which restricts the development of CWTB-modified asphalt. In this study, the mechanism of CWTB modification of asphalt was explored in depth by dynamic mechanical analysis (DMA), fluorescence microscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and molecular dynamics (MD) simulations. The results of the study showed that CWTB enhanced the high temperature performance of the base asphalt. The microscopic mechanism by which this phenomenon occurs is that CWTB has the largest binding energy with the aromatics (1100–1400 kcal/mol), followed by the saturates (700–900 kcal/mol), followed by the resins (200–450 kcal/mol), and the smallest binding energy with the asphaltenes (110–160 kcal/mol), which causes CWTB to absorb the light components of the asphalt (aromatics and saturates). In the process of absorbing the light components, CWTB will gradually swell, which causes CWTB to bind more and more tightly with the base asphalt, and eventually the good high temperature performance of CWTB is transferred to the base asphalt. The macroscopic manifestation of this process is that the rutting factor of CWTB modified asphalt is significantly higher than that of virgin asphalt. This study can provide basic theoretical support for the application of CWTB modified asphalt.


Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2393 ◽  
Author(s):  
Salaheldin Elkatatny

Drilling in high-pressure high-temperature (HPHT) conditions is a challenging task. The drilling fluid should be designed to provide high density and stable rheological properties. Barite is the most common weighting material used to adjust the required fluid density. Barite settling, or sag, is a common issue in drilling HPHT wells. Barite sagging may cause many problems such as density variations, well-control problems, stuck pipe, downhole drilling fluid losses, or induced wellbore instability. This study assesses the effect of using a new copolymer (based on styrene and acrylic monomers) on the rheological properties and the stability of an invert emulsion drilling fluid, which can be used to drill HPHT wells. The main goal is to prevent the barite sagging issue, which is common in drilling HPHT wells. A sag test was performed under static (vertical and 45° incline) and dynamic conditions in order to evaluate the copolymer’s ability to enhance the suspension properties of the drilling fluid. In addition, the effect of this copolymer on the filtration properties was performed. The obtained results showed that adding the new copolymer with 1 lb/bbl concentration has no effect on the density and electrical stability. The sag issue was eliminated by adding 1 lb/bbl of the copolymer to the invert emulsion drilling fluid at a temperature >300 °F under static and dynamic conditions. Adding the copolymer enhanced the storage modulus by 290% and the gel strength by 50%, which demonstrated the power of the new copolymer to prevent the settling of the barite particles at a higher temperature. The 1 lb/bbl copolymer’s concentration reduced the filter cake thickness by 40% at 400 °F, which indicates the prevention of barite settling at high temperature.


Author(s):  
Zefeng Wang ◽  
Yutao Jiang ◽  
Chao Pan

The resource reclamation of waste tire rubber (WTR) is regarded as the most suitable strategy for these solid wastes. Water jet pulverization (WJPul) is a sustainable reclamation technique for WTR, since both size reduction and rubber devulcanization can be achieved. Aiming at understanding the mechanisms related with pulverization and devulcanization of WTR, this work detailed the interactions between WTR and high pressure water jet (HPWJ). The results show that WJPul can be defined as a mechanochemical process for WTR. The compressive shear failure of rubber mainly induces rubber devulcanization and results in fine ground tire rubber (GTR) particles, HPWJ erosion mainly intensifies rubber depolymerization and results in coarse GTR particles. Chemical reactions can be detected between the devulcanized GTR from WJPul and asphalts, thus resulting in better modification performances of GTR from WJPul in asphalt. The results can help better understand the WJPul mechanisms and provide guidelines for WJPul application.


2021 ◽  
pp. 130113
Author(s):  
Gang Xu ◽  
Peipei Kong ◽  
Yunhong Yu ◽  
Jingyao Yang ◽  
Minghui Zhu ◽  
...  

2019 ◽  
Vol 74 (4) ◽  
pp. 357-363
Author(s):  
Daniela Vitzthum ◽  
Hubert Huppertz

AbstractThe mixed cation triel borate Ga4In4B15O33(OH)3 was synthesized in a Walker-type multianvil apparatus at high-pressure/high-temperature conditions of 12.5 GPa and 1300°C. Although the product could not be reproduced in further experiments, its crystal structure could be reliably determined via single-crystal X-ray diffraction data. Ga4In4B15O33(OH)3 crystallizes in the tetragonal space group I41/a (origin choice 2) with the lattice parameters a = 11.382(2), c = 15.244(2) Å, and V = 1974.9(4) Å3. The structure of the quaternary triel borate consists of a complex network of BO4 tetrahedra, edge-sharing InO6 octahedra in dinuclear units, and very dense edge-sharing GaO6 octahedra in tetranuclear units.


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