Effects of Styrene-Butadiene Rubber/Carboxymethylcellulose (SBR/CMC) and Polyvinylidene Difluoride (PVDF) Binders on Low Temperature Lithium Ion Batteries

Low-temperature cracking is a major distress mode in Alaskan pavements because of the extreme temperature conditions—which range, in some instances, from about −50°C in winter to more than 40°C in summer. The use of asphalt modifiers in Alaskan pavements occurred over the past 15 years. These modifiers include Styrene-Butadiene-Styrene polymers, Styrene-Butadiene-Rubber polymers, ULTRAPAVE, and CRM [both the dry process (PlusRide) and the wet process]. Field observations and laboratory studies in Alaska and elsewhere indicate that the use of these modifiers would improve the low-temperature cracking resistance of pavements. The degree to which these modifiers provide beneficial effects for Alaskan pavements needs to be evaluated. The objectives of this research were (1) To characterize asphalt and polymer modified asphalt from a number of selected sites using Superpave PG grading system and to conduct thermal stress restrained specimen tests (TSRST) and Superpave IDT laboratory tests on field specimens; (2) To compare low-temperature cracking performance using field surveys; (3) To verify the applicability of the Superpave thermal cracking model (TCMODEL) and other available models for predicting low temperature cracking; and (4) To recommend guidelines for predicting minimum pavement temperatures in Alaska. Results of this study indicate, in general, significant improvement in low-temperature cracking resistance when polymer modifiers are used. Comparisons between predicted and observed low-temperature cracking using available crack propagation models, including Superpave TCMODEL, were poor. An improved regression model was developed using minimum air temperature, TSRST fracture temperature and strength, and pavement age to fit the observed field data for both conventional and polymer modified sections.

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Modification Mechanism of Asphalt Modified with Rock Asphalt and Styrene-Butadiene Rubber (SBR)

Advances in Civil Engineering ◽

10.1155/2021/5533441 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Xiangming Deng ◽

Hui Huang ◽

Bin Wang ◽

Jie Chen

Keyword(s):

Low Temperature ◽

High Performance ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Modified Asphalt ◽

Temperature Performance ◽

Low Temperature Performance ◽

Styrene Butadiene ◽

Compound Modification ◽

Rheometer Test

High-performance asphalt binder plays an important role in the durable asphalt pavement. Asphalt modified by rock asphalt (RA) is one of the high-performance modified asphalt materials. It was used in road engineering as a relatively environmentally friendly material, because rock asphalt takes some advantages of large reserves, easy treatment, and efficient modification. Moreover, the main component of rock asphalt is bitumen, which enables it to substitute part of the binder used in asphalt mixtures. On the other hand, the negative low-temperature performance of RA modified asphalt impeded its application in cold regions. The object of this paper is to improve the low-temperature performance of RA modified asphalt by compound modified with styrene-butadiene rubber (SBR). The 70-penetration grade binder and the RA modified asphalt with 15% RA by weight were applied as the base binder. Five types of RA-SBR modified asphalt were prepared, and the content of SBR was 2%, 4%, 5%, 6% and 8% by weight of BRA modified binder. The Fourier transform infrared spectroscopy (FTIR) tests were utilized to illustrate the reasons for the poor low-temperature performance of BRA modified asphalt and reveal the compound modification mechanism of BRA-SBR modified asphalt. The Brookfield viscosity test, dynamic shear rheometer test, and bending beam rheometer test were adopted to reveal the variation patterns of rheological behavior and low-temperature performance with mass contents of SBR. The test results indicated that the worse of low-temperature performance was caused by the increase of asphaltene content and the stress concentration due to ash in RA modified asphalt. And the compound modification is a physical process. The addition of SBR has improved the low-temperature performance of RA modified asphalt dramatically. And based on the rheological behaviors and low-temperature performance of RA-SBR compound modified asphalt, the optimum content of SBR was determined, which is about 4%∼5%.

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Influence of electrolyte additive of trimethylsilylisocyanate on properties of electrode with nanosilicon for lithium-ion batteries

Himia Fizika ta Tehnologia Poverhni ◽

10.15407/hftp12.01.067 ◽

2021 ◽

Vol 12 (1) ◽

pp. 67-78

Author(s):

S. P. Kuksenko ◽

◽

H. O. Kaleniuk ◽

Yu. O. Tarasenko ◽

M. T. Kartel ◽

...

Keyword(s):

Lithium Ion Batteries ◽

Elevated Temperatures ◽

Lithium Ion ◽

Reversible Capacity ◽

High Energy ◽

Organic Electrolyte ◽

Partial Replacement ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Fluoroethylene Carbonate

Even partial replacement of graphite in the anode of lithium-ion batteries with silicon can significantly increase their specific energy. But the issue is the insufficient life cycle of such batteries due to the accelerated degradation of the liquid organic electrolyte with traditional lithium hexafluorophosphate, especially at elevated temperatures. The subject of discussions and further research are the processes involving a natural oxide layer on the surface of silicon in the manufacture and electrochemical litiation–delitiation of Si-containing electrodes. Among the most promising areas for solving the issues of practical application of silicon are new additives to the electrolyte and polymeric binders for electrode masses. This paper demonstrates the capability of trimethylsilylisocyanate (with aminosilane and isocyanate functional groups) as an additive to a liquid organic electrolyte (LiPF6 / fluoroethylene carbonate + ethyl methyl carbonate + vinylene carbonate + ethylene sulfite) to scavenge the reactive HF and PF5 species that alleviates the thermal decomposition of fluoroethylene carbonate at elevated temperatures. This makes it possible to increase the electrochemical parameters of half-cells with a hybrid graphite–nanosilicon working electrode when using water-based binders – carboxymethylcellulose and styrene-butadiene rubber. The addition of trimethylsilylisocyanate in the electrolyte significantly improves the reversible capacity of hybrid electrodes and reduces the accumulated irreversible capacity during prolonged cycling at normal temperature and after exposure at 50 °C, therefore to be effective for use in high-energy lithium-ion batteries.

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Improvement of Low-Temperature Performance of Buton Rock Asphalt Composite Modified Asphalt by Adding Styrene-Butadiene Rubber

Materials ◽

10.3390/ma12152358 ◽

2019 ◽

Vol 12 (15) ◽

pp. 2358 ◽

Cited By ~ 2

Author(s):

Xiyan Fan ◽

Weiwei Lu ◽

Songtao Lv ◽

Fangwei He

Keyword(s):

Low Temperature ◽

High Speed ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Stiffness Modulus ◽

Modified Asphalt ◽

Temperature Performance ◽

Brittle Point ◽

Low Temperature Performance ◽

Styrene Butadiene

To improve the low-temperature performance of the Buton rock asphalt (BRA)-modified asphalt, styrene-butadiene rubber (SBR) was added to it. The BRA-modified asphalt and SBR-BRA composite modified asphalt were prepared by high-speed shearing method. The penetration, softening point, ductility, and Brookfield viscosity of the two kinds of asphalt were measured. The dynamic shear rheometer (DSR) and the beam bending rheometer (BBR) were employed to research the performance of BRA-modified asphalt by adding SBR. The results showed that the pure asphalt in BRA was the main reason to reduce the low-temperature performance of neat asphalt when the content of BRA was 19%. However, the ash in BRA was the main factor to reduce the low-temperature performance when its content was more than 39.8%. When the BRA content was 59.8%, the SBR-BRA composite modified asphalt with SBR contents of 2%, 4%, 6%, and 8%, and it shows that the penetration and ductility of the BRA-modified asphalt are increased by the addition of SBR. The equivalent brittle point was reduced, the stiffness modulus was decreased, and the creep rate was increased. At the same time, the Brookfield viscosity was reduced and the rutting factor was increased. The stiffness modulus of the SBR-BRA composite modified asphalt mixture was increased. That is to say, when SBR was mixed into the BRA-modified asphalt, the low-temperature performance could be remarkably improved based on ensuring high-temperature performance. The low-temperature index of composite modified asphalt was analyzed. It was recommended to apply the equivalent brittle point to evaluate the low-temperature performance of SBR-BRA composite modified asphalt.

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