Viscoelastic Properties of Elastomers and Tire Wet Skid Resistance

1997 ◽  
Vol 70 (4) ◽  
pp. 584-594 ◽  
Author(s):  
H. Takino ◽  
R. Nakayama ◽  
Y. Yamada ◽  
S. Kohjiya ◽  
T. Matsuo
Keyword(s):  
Systems Analysis ◽  
Viscoelastic Properties ◽  
Skid Resistance ◽  
Polymer Systems ◽  
The Past ◽  
Rubber Friction ◽  
Wide Range ◽  
Tan Δ ◽  
Peak Value ◽  
Wet Skid Resistance

Abstract Many studies concerning tire wet skid resistance have been published in the past, but they have in general involved the use of only a few grades of SBR and BR. We have evaluated the British Portable Skid Tester (BPST) wet skid resistance of eighteen sulfur curable polymers which might be used for automobile tires. These results have been analyzed in relation to the viscoelastic properties of the polymer systems. Analysis of wet skid resistance in terms of the peak value of tan δ over a prescribed temperature range, designated as Tα, and abrasion loss—derived from the theory of rubber friction—was concluded to give a better general relationship for a wide range of polymers.

Effects of Carbon Black and Process Oil on Viscoelastic Properties and Tire Wet Skid Resistance

1998 ◽  
Vol 26 (4) ◽  
pp. 241-257 ◽  
Author(s):  
H. Takino ◽  
H. Takahashi ◽  
K. Yamano ◽  
S. Kohjiya
Keyword(s):  
Carbon Black ◽  
Viscoelastic Properties ◽  
Hysteresis Loss ◽  
Poor Correlation ◽  
Skid Resistance ◽  
Good Relationship ◽  
Rubber Friction ◽  
Wide Range ◽  
Tan Δ ◽  
Wet Skid Resistance

Abstract Wet skid resistance for rubbers with a wide range of carbon black loadings and process oil loadings was investigated from the viewpoints of viscoelastic properties and abrasion properties. An analysis of wet skid resistance by the factors of Tα and BPST abrasion, which was effectively performed on a wide range of polymers in a previous report, gave a poor correlation this time. In the case of a wide range of carbon black loadings and oil loadings, the factors of tan δ and BPST abrasion had a good relationship with wet skid resistance. In this study, tan δ at 7°C was found to be a suitable factor corresponding to adhesion loss and hysteresis loss in rubber friction. By the evaluation of abrasions, BPST abrasion and PICO abrasion were estimated to be governed by different mechanisms.

Relationships Between the Friction and Viscoelastic Properties of Rubber

2000 ◽  
Vol 28 (3) ◽  
pp. 178-195 ◽  
Author(s):  
N. Amino ◽  
Y. Uchiyama
Keyword(s):  
Viscoelastic Properties ◽  
Skid Resistance ◽  
Grain Sizes ◽  
Abrasive Grain ◽  
The Coefficient Of Friction ◽  
Tan Δ ◽  
Silicone Carbide ◽  
And Storage ◽  
Wet Skid Resistance ◽  
Frequency Curves

Abstract In this study, the relationships between friction and viscoelastic properties such as loss tangent tan δ and storage modulusE′ were examined. Wet skid resistance was measured using the British Pendulum Tester. The rubber specimens were rubbed againstfive silicone carbide cloths of differing abrasive grain sizes. The viscoelastic properties of the rubber specimens were measured with a viscoelasticspectrometer. From the data on wet skid resistance and viscoelastic properties, it is found that the coefficient of friction μ varies as follows:           μ = a + b · tan δ/E′ where a and b are constants. Tan δ/E′ was related to the hysteresis term of friction, and the μ-frequency curves were compared with the tan δ/E′ –frequency curves.

scholarly journals Maleic Anhydride Modified Dicyclopentadiene Resin for Improving Wet Skid Resistance of Silica Filled SSBR/BR Composites

2020 ◽  
Vol 10 (13) ◽  
pp. 4478 ◽  
Author(s):  
Ruoming Huang ◽  
Qiwei Pan ◽  
Zhaohui Chen ◽  
Kunhao Feng
Keyword(s):  
Maleic Anhydride ◽  
Contact Angles ◽  
Styrene Butadiene Rubber ◽  
Skid Resistance ◽  
Butadiene Rubber ◽  
Maximum Enhancement ◽  
Water Contact ◽  
Tan Δ ◽  
Styrene Butadiene ◽  
Wet Skid Resistance

As commercial rubber in tires, silica-filled solution-polymerized styrene-butadiene rubber/butadiene rubber (SSBR/BR) compounds exhibited preferable wet skid resistance (WSR) properties, which could be further enhanced by the incorporation of some oligomeric resins. However, the untreated dicyclopentadiene (DCPD) resin shows a slight improvement in wet friction even if the good compatibility between DCPD and SBR owing to their common cyclic structures. For this problem to be addressed, we aimed to enhance its resin-silica interaction by reaction with maleic anhydride (MAH). In detail, the effect of MAH content on WSR, curing characteristics, physical-mechanical properties of the silica-filled SSBR/BR composites was investigated. When the MAH content is 4 wt% in the modified DCPD resin, the maximum enhancement of about 15% in tan δ values at 0 °C, as well as that of 17% in British pendulum skidding tester (BPST) index is obtained, indicating a desirable improvement in WSR. In addition of these two commonly used methods, water contact angles of the vulcanizates increase gradually with increasing MAH content, further confirming the remarkable performance of modified DCPD resin in WSR.

scholarly journals Preparation and Performance of Silica/ESBR Nanocomposites Modified by Bio-Based Dibutyl Itaconate

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1820 ◽  
Author(s):  
Haijun Ji ◽  
Hui Yang ◽  
Liwei Li ◽  
Xinxin Zhou ◽  
Lan Yin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Rolling Resistance ◽  
Styrene Butadiene Rubber ◽  
Skid Resistance ◽  
Butadiene Rubber ◽  
Modified Silica ◽  
Tan Δ ◽  
Styrene Butadiene ◽  
Hydroxy Groups ◽  
Wet Skid Resistance

Ester-functionalized styrene-butadiene rubber (dibutyl itaconate-styrene-butadiene rubber) (D-ESBR) was synthesized by low-temperature emulsion polymerization using dibutyl itaconate (DBI) as a modified monomer containing ester groups. Nonpetroleum-based silica with hydroxy groups was used as a filler to enhance the D-ESBR, which can provide excellent mechanical properties, low rolling resistance, and high wet skid resistance. During the preparation of the silica/D-ESBR nanocomposites, a hydrogen-bonding interface was formed between the hydroxy groups on the surface of silica and the ester groups in the D-ESBR macromolecules. As the content of ester groups in the D-ESBR increases, the dispersion of silica in the nanocomposites is gradually improved, which was verified by rubber process analyzer (RPA) and scanning electron microscopy (SEM). Overall mechanical properties of the silica/D-ESBR modified with 5 wt % DBI were improved and became superior to that of the non-modified nanocomposite. Compared with the non-modified silica/D-ESBR, the DBI modified silica/D-ESBR exhibited a lower tan δ value at 60 °C and comparable tan δ value at 0 °C, indicating that the DBI modified silica/D-ESBR had lower rolling resistance without sacrificing wet skid resistance.

Tread Wear and Wet Skid Resistance of Butadiene-Styrene Elastomers and Blends

1971 ◽  
Vol 44 (4) ◽  
pp. 996-1014 ◽  
Author(s):  
R. N. Kienle ◽  
E. S. Dizon ◽  
T. J. Brett ◽  
C. F. Eckert
Keyword(s):  
Viscoelastic Properties ◽  
Combined Effect ◽  
Wear Loss ◽  
Skid Resistance ◽  
Wear Factor ◽  
Factors Affecting ◽  
Material Factor ◽  
Relationship Of ◽  
Wet Skid Resistance ◽  
Butadiene Styrene

Abstract 1. Car, wheel position, driver, inflation pressure, and shoulder drop have a statistically significant effect upon wear loss and need to bo taken into consideration before material factors affecting wear can be studied. 2. Variations in macrostructure of the polymers are not found to have a significant effect on wear as compared to microstructure variations. 3. At least two material factors control wear loss of tire treads. 4. When polymers are tested near their glass transition temperature (within 80° C), wear loss is dominated by viscoelastic properties. Viscoelastic properties can be related to wear loss through Tg or the combined effect of the cis, trans, vinyl, and styrene content. 5. At higher test temperatures (over 100° C above Tg) wear loss is dominated by a material factor that has a positive correlation with temperature. This is particularly noticeable when treads are worn under mild conditions. However, there is evidence that this wear factor is present at the testing nearer to Tg but is masked by the dominant viscoelastic effect. 6. The combined effect upon wear of the different material factors leads to an optimum wear resistance for any polymer in the butadiene—styrene system in the range of 75°–105° C above the Tg for that polymer. 7. For polymers tested at the same ambient temperature, (T), the effect of viscoelastic properties decreases non-linearly as T−Tg increases. 8. In the range of test severity studied, severity has little effect upon the inter-relationship of material factors. 9. In the range of test temperature where Tg dominates wear loss, skid distance on wet asphalt pavement is inversely related to wear rating.

scholarly journals Issues in the Prediction of the Mechanical Properties of Open Graded Mixes

2018 ◽  
Vol 2672 (40) ◽  
pp. 32-40 ◽  
Author(s):  
Hong Zhang ◽  
Kumar Anupam ◽  
Athanasios Scarpas ◽  
Cor Kasbergen
Keyword(s):  
Mechanical Properties ◽  
Asphalt Concrete ◽  
Road Network ◽  
Skid Resistance ◽  
Premature Failure ◽  
Asphalt Mixes ◽  
The Past ◽  
Design Life ◽  
Pavement Engineering ◽  
Wet Skid Resistance

Within the pavement engineering community, open graded mixes (OGM) are regarded as mixes capable of reducing noise and improving wet skid resistance. However, during their design life, these asphalt mixes are known to suffer from a particular distress type known as raveling. This results in a premature failure of a road network. In order to study the propensity of OGM to raveling, homogenization-based approaches are considered to be accessible and effective. One of the most widely accepted homogenization models for asphalt concrete is proposed by Christensen et al. Several studies related to homogenization techniques have been conducted in the past; however, to the best of the authors’ knowledge not a lot of attention has been paid to the study of OGM by means of homogenization models. The other limitation of the Christensen model is that some parameters are difficult to physically understand. Under the above realization, the objective of the paper is twofold: (1) to propose a modification of the Christensen model for OGM; and (2) to verify the modified model’s capability in predicting the mechanical properties of OGM. In general, it was found that once the proposed factor is calibrated for a given OGM by laboratory tests the obtained results are accurate.

Optical Properties of HVEM Accelerators

1975 ◽  
Vol 33 ◽  
pp. 180-181
Author(s):  
A. Strojnik ◽  
J.W. Scholl ◽  
V. Bevc
Keyword(s):  
Optical Properties ◽  
Electron Accelerator ◽  
Systematic Investigation ◽  
Electron Source ◽  
High Brightness ◽  
The Past ◽  
Wide Range ◽  
Optical Behavior

The electron accelerator, as inserted between the electron source (injector) and the imaging column of the HVEM, is usually a strong lens and should be optimized in order to ensure high brightness over a wide range of accelerating voltages and illuminating conditions. This is especially true in the case of the STEM where the brightness directly determines the highest resolution attainable. In the past, the optical behavior of accelerators was usually determined for a particular configuration. During the development of the accelerator for the Arizona 1 MEV STEM, systematic investigation was made of the major optical properties for a variety of electrode configurations, number of stages N, accelerating voltages, 1 and 10 MEV, and a range of injection voltages ϕ0 = 1, 3, 10, 30, 100, 300 kV).

Pursuit of the Abscopal Effect

2020 ◽  
Vol 04 (04) ◽  
pp. 369-372
Author(s):  
Paul B. Romesser ◽  
Christopher H. Crane
Keyword(s):  
Tumor Immunology ◽  
Antitumor Immunity ◽  
Clinical Success ◽  
Immune Recognition ◽  
Immune Modulators ◽  
Cancer Subtypes ◽  
The Past ◽  
Tumor Irradiation ◽  
Wide Range ◽  
Tumor Recognition

AbstractEvasion of immune recognition is a hallmark of cancer that facilitates tumorigenesis, maintenance, and progression. Systemic immune activation can incite tumor recognition and stimulate potent antitumor responses. While the concept of antitumor immunity is not new, there is renewed interest in tumor immunology given the clinical success of immune modulators in a wide range of cancer subtypes over the past decade. One particularly interesting, yet exceedingly rare phenomenon, is the abscopal response, characterized by a potent systemic antitumor response following localized tumor irradiation presumably attributed to reactivation of antitumor immunity.

The Many Pasts of Detective Fiction

2020 ◽  
Vol 1 (2) ◽  
pp. 157-172
Author(s):  
Thomas Leitch
Keyword(s):  
Detective Fiction ◽  
Golden Age ◽  
Public History ◽  
Detective Novel ◽  
Sherlock Holmes ◽  
Detective Story ◽  
The Past ◽  
Wide Range ◽  
Detective Novels ◽  
The Many

Building on Tzvetan Todorov's observation that the detective novel ‘contains not one but two stories: the story of the crime and the story of the investigation’, this essay argues that detective novels display a remarkably wide range of attitudes toward the several pasts they represent: the pasts of the crime, the community, the criminal, the detective, and public history. It traces a series of defining shifts in these attitudes through the evolution of five distinct subgenres of detective fiction: exploits of a Great Detective like Sherlock Holmes, Golden Age whodunits that pose as intellectual puzzles to be solved, hardboiled stories that invoke a distant past that the present both breaks with and echoes, police procedurals that unfold in an indefinitely extended present, and historical mysteries that nostalgically fetishize the past. It concludes with a brief consideration of genre readers’ own ambivalent phenomenological investment in the past, present, and future each detective story projects.

Nine Centuries of Man

2017 ◽  
Keyword(s):  
Twentieth Century ◽  
Diverse Range ◽  
Gender Expectations ◽  
Court Records ◽  
The Past ◽  
Wide Range ◽  
Police Reports ◽  
Late Twentieth ◽  
Scottish History ◽  
Late Twentieth Century

What did it mean to be a man in Scotland over the past nine centuries? Scotland, with its stereotypes of the kilted warrior and the industrial ‘hard man’, has long been characterised in masculine terms, but there has been little historical exploration of masculinity in a wider context. This interdisciplinary collection examines a diverse range of the multiple and changing forms of masculinities from the late eleventh to the late twentieth century, exploring the ways in which Scottish society through the ages defined expectations for men and their behaviour. How men reacted to those expectations is examined through sources such as documentary materials, medieval seals, romances, poetry, begging letters, police reports and court records, charity records, oral histories and personal correspondence. Focusing upon the wide range of activities and roles undertaken by men – work, fatherhood and play, violence and war, sex and commerce – the book also illustrates the range of masculinities that affected or were internalised by men. Together, the chapters illustrate some of the ways Scotland’s gender expectations have changed over the centuries and how, more generally, masculinities have informed the path of Scottish history

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