Winter Traction Research Articles

A Blocked Mercapto Silane Functionalized Silica Decorated‐Aramid Nanofiber to Evolve Elastomer/Silica Composite for Energy‐Efficient Tire

ABSTRACTIn situ generated nanosilica particles were grafted onto aramid nanofibers while modified with a blocked mercapto silane (3‐Octanoylthio‐1‐propyltriethoxysilane). Nanofibers were derived from macro aramid fibers (poly (p‐phenylene terephthalamide)). Fourier‐transform infrared spectroscopy and x‐ray photoelectron spectroscopy revealed that the direct condensation reaction between the silane's ethoxy groups and the nanofiber's hydroxyl or carboxylic groups forms SiO‐C bonds. Morphological analysis of nanofibers revealed the formation of nanosilica from unreacted residual silane on the modified nanofiber (A‐NM) surface. In situ silica formation caused SiOSi bond formation, according to the spectroscopic analysis. Styrene butadiene rubber‐silica composites with modified nanofiber additive were prepared. The bound rubber content and filler flocculation rate displayed an improvement in nanofiber dispersion and rubber‐nanofiber interaction after silane modification. Mechanical characteristics of the composites improved after rubber and modified nanofiber interaction, dispersion, and strengthening. The nanofibers evenly distributed during mixing, as proven by morphological analysis of composites. Incorporation of 1 phr of A‐NM increased tensile strength by 16% and abrasion resistance by 3.1%. Composite's rolling resistance indicator (6.2%) and winter traction indicator increased at high temperatures with 1 phr of A‐NM loading. This specialized filler decorated nanofibers could be used as energy‐efficient tire additives as an alternative to other trendy commercial materials.

NITROGEN-CONTAINING SILANE COUPLING AGENTS: SYNTHESIS AND STRUCTURE EFFECT ON TIRE PERFORMANCE OF SILICA/SSBR/BR COMPOSITES

ABSTRACT We report synthesis of nitrogen-containing silane coupling agents (N-SCAs) and their use in a 1:1 mixture by weight with bis(triethoxysilylpropyl)tetrasulfide preparation of silica/solution SBR (SSBR)/BR composites. These N-SCAs contain in their structures, inter alia, a tertiary amine center (N1, N2), a carbamate (N3), or a urea (N4) group. In addition, N1, N3, and N4 were equipped with allyl side arms to increase the hydrophobization effect of silica particle as well as to achieve a balance between the filler–filler and filler–matrix networks being formed. By contrast, N2 consists of glycidyl side arms that contribute to the filler–filler interaction even more. The silica/SSBR/BR blends and subsequent vulcanizates were prepared and then thoroughly investigated via dynamic mechanical analysis, rubber process analysis, and tensile testing. The composite based on N1 (V/N1) exhibited exceptionally great tensile strength, abrasion resistance, and winter traction, accompanied by soft hysteresis. Therefore, N1 has potential applications in preparation of winter tire tread materials.

Effects of a randomized controlled hiking intervention on daily activities, sleep, and stress among adults during the COVID-19 pandemic

BackgroundPhysical activity promotes health, and physical activity done outdoors in nature may be particularly beneficial. We conducted two randomized studies to examine the implementation of a winter hiking intervention and whether this intervention affected activity choices and aspects of well-being during the COVID-19 pandemic.MethodsConvenience samples of adults (n = 53; n = 51) were recruited into two different randomized studies in 2021 and 2022 respectively. Participants completed online surveys at baseline and 6 and 11–12 weeks later. Participants were randomized to a study group (intervention or control) shortly after the baseline assessments. In both studies, the intervention group received free access to a regional winter hiking challenge. In the second study, we also provided winter traction cleats to this group to facilitate engagement in the hiking challenge. Descriptive statistics were used to summarize intervention implementation, including participants’ engagement in challenge hikes. Repeated measures ANOVA models were used to test intervention effects on key outcome variables, including hiking frequency via the Pleasant Activities List, stress via the Perceived Stress Scale, and sleep duration via the Pittsburgh Sleep Quality Index.ResultsIn the first study, the intervention group’s engagement in challenge hikes was low (38.5%); reported barriers included access to winter hiking equipment. In the second study, when winter traction cleats were provided, engagement in the intervention was higher, and the intervention increased hiking frequency and improved sleep. There were no significant intervention effects on stress, but the direction of effects was in the expected direction.ConclusionsResults highlight some potential positive impacts of this intervention designed to facilitate access to winter hiking. Future research could examine whether effects are stronger in a larger sample, in which additional barriers to engagement are addressed.Trial registrationThis study was registered at clinicaltrials.gov on 28/12/2020 prior to participant enrollment (NCT04685681), https://clinicaltrials.gov/ct2/show/NCT04685681.

Effect of feldspar filler on physical and dynamic properties of SBR/CB based tire tread compounds: Effect of addition method of silane coupling agent

In this work, the effects of using feldspar (FLD) as an alumina-silicate inorganic filler, with carbon black (CB) as a novel binary filler system, on the properties of SBR compounds were investigated for tire applications. The bis(triethoxysilylpropyl) disulfide (TESPD) was used for modification of FLD. The SBR hybrid composites were produced by replacing 10 phr of CB filler with neat FLD and functionalized FLD (F-FLD). The TESPD was added directly to the rubber mixture including neat FLD. The SBR composite which has only CB filler (50CB) was found to have the highest damping parameter (tan δ) value at 60°C. On the other hand, the composites loaded with the CB and the FLD fillers exhibited relatively lower tan δ at the same temperature showing lower rolling resistance meaning better fuel saving performance. The lowest rolling resistance was achieved for the 40CB-10F-FLD most probably due to its stronger interaction with the SBR elastomer molecules through the silane agent-assisted crosslinks of the F-FLD. As another dynamic property, the storage moduli at −20°C were found to be lower for the SBR hybrid composites as compared to that of the 50CB composite, exhibiting enhanced winter traction performance of the composites having FLD filler together with CB. The composites containing only 10 phr of FLD and F-FLD, on the other hand, exhibited very low tensile strength values which are not acceptable for tire tread materials.

Wet Dust Sampler\u2014a Sampling Method for Road Dust Quantification and Analyses

In northern countries, the climate, and consequently the use of studded tyres and winter traction sanding, causes accumulation of road dust over winter and spring, resulting in high PM10 concentrations during springtime dusting events. To quantify the dust at the road surface, a method—the wet dust sampler (WDS)—was developed allowing repeatable sampling also under wet and snowy conditions. The principle of operation is flushing high-pressurised water over a defined surface area and transferring the dust laden water into a container for further analyses. The WDS has been used for some time and is presented in detail to the international scientific community as reported by Jonsson et al. (2008) and Gustafsson et al. (2019), and in this paper, the latest version is presented together with an evaluation of its performance. To evaluate the WDS, the ejected water amount was measured, as well as water losses in different parts of the sampling system, together with indicative dust measurement using turbidity as a proxy for dust concentration. The results show that the WDS, when accounting for all losses, have a predictable and repeatable water performance, with no impact on performance based on the variety of asphalt surface types included in this study, given undamaged surfaces. The largest loss was found to be water retained on the surface, and the dust measurements imply that this might not have as large impact on the sampled dust as could be expected. A theoretical particle mass balance shows small particle losses, while field measurements show higher losses. Several tests are suggested to validate and improve on the mass balances. Finally, the WDS is found to perform well and is able to contribute to further knowledge regarding road dust implications for air pollution.

Improving Winter Traction and Fuel Economy of Car Tires Using Naphthenic Tire Oils

Improving Winter Traction and Fuel Economy of Car Tires Using Naphthenic Tire Oils

Processing optimization of latex‐compounded montmorillonite/styrene‐butadiene rubber–polybutadiene rubber

ABSTRACTOrgano‐montmorillonite was incorporated into model tire tread formulations through latex compounding methods, to evaluate its effects on elastomer reinforcement and dynamic properties. An intercalation structure was obtained by applying latex compounding method to prepare organoclay‐emulsion stryene butadiene (E‐SBR) masterbatches, for compounding with organoclay loading levels of 0–20 parts per hundred rubber (phr). Microstructure, curing properties and tire performance of the compounded rubber were investigated with the aid of X‐ray diffraction, rheometor and dynamic‐mechanical analysis, respectively. The results showed that organo‐montmorillonite filler provided effective reinforcement in the elastomer matrix, as indicated through mechanical and dynamic mechanical properties. Tread compounds using higher organoclay loadings displayed preferred ice traction, wet traction, and dry handling, but decreased winter traction and rolling resistance. Model compounds using 15 phr of organoclay loading levels were preferred for balanced physical and dynamic properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41521.

Influence of Pattern Void on Hydroplaning and Related Target Conflicts

Abstract Performance prediction of hydroplaning via coupling of computational fluid dynamics (CFD) and FE modeling has delivered a detailed insight into the local mechanisms and root causes of hydroplaning but is still very time consuming and extensive. The goal of the present work is the development of simple rules of thumb and easy to understand models to give the tire designer a quick approach to optimize the hydroplaning performance of his design concepts including the target conflicting trade-offs. Based on the DOE study covering basic winter and summer tread patterns and tread compounds taking into account interactions, total void, longitudinal, and lateral void distributions have been varied. Experimental designs have been tested concerning longitudinal hydroplaning behavior on front and rear driven cars and lateral hydroplaning. Most important target conflicting performance criteria such as wet and dry braking, noise, rolling resistance, winter traction, and force and moment characteristics among others have been tested additionally. The existing models using hydrodynamic pressure influences have been reviewed and extended. A simple to use development tool has been programed to quantify pattern design to get a quick prediction of tire performance changes (“Void Slider”).

Properties and toxicological effects of particles from the interaction between tyres, road pavement and winter traction material

In regions where studded tyres and traction material are used during winter, e.g. the Nordic countries, northern part of USA, Canada, and Japan, mechanically generated particles from traffic are the main reason for high particle mass concentrations in busy street and road environments. In many Nordic municipalities the European environmental quality standard for inhalable particles (PM 10) is exceeded due to these particles. In this study, particles from the wear of studded and studless friction tyres on two pavements and traction sanding were generated using a road simulator. The particles were characterized using particle sizers, Particle Induced X-Ray Emission Analysis and electron microscopy. Cell studies were conducted on particles sampled from the tests with studded tyres and compared with street environment, diesel exhaust and subway PM 10, respectively. The results show that in the road simulator, where resuspension is minimized, studded tyres produce tens of times more particles than friction tyres. Chemical analysis of the sampled particles shows that the generated wear particles consist almost entirely of minerals from the pavement stone material, but also that Sulfur is enriched for the submicron particles and that Zink is enriched for friction tyres for all particles sizes. The chemical data can be used for source identification and apportionment in urban aerosol studies. A mode of ultra-fine particles was also present and is hypothesised to originate in the tyres. Further, traction material properties affect PM 10 emission. The inflammatory potential of the particles from wear of pavements seems to depend on type of pavement and can be at least as potent as diesel exhaust particles. The results imply that there is a need and a good potential to reduce particle emission from pavement wear and winter time road and street operation by adjusting both studded tyre use as well as pavement and traction material properties.

Evaluation of Isobutylene-Based Elastomers in a Model Winter Tire Tread

Abstract The performance of butyl, chlorobutyl, bromobutyl, and brominated isobutylene-co-para-methylstyrene (BIMS) rubbers were evaluated versus a solution-polymerized styrene-butadiene rubber with 20% bound styrene in model winter tire tread formulations containing natural rubber and butadiene rubber. Isobutylene-based elastomer performance was compared in carbon black-filled and silane-coupled silica-filled systems. Based on laboratory dynamic properties predictive of wet and winter traction, and on DIN abrasion index values, BIMS is the elastomer of choice affording increased tangent delta values between 0 °C and −40 °C, and the highest DIN abrasion index values of the isobutylene-based elastomers. Evaluation of BIMS / NR / BR blends in model compounds show its utility as a tread polymer for improving winter performance.

Traction Performance of Transit and Paratransit Vehicles in Winter

The traction performance of transit and paratransit vehicles during the winter is an important factor in public transportation system operations. Vehicle traction forces are significantly reduced on snowy or icy surfaces, specifically during stopping, starting, cornering, and hill climbing. Reduced traction increases stopping distances and decreases controllability when a vehicle stops in an emergency situation. This study evaluated the traction performance of transit and paratransit vehicles on snowy and icy surfaces. Field tests were conducted in Fairbanks, Alaska, using three types of vehicles—a 41-passenger transit bus, a 32-passenger transit bus, and a 9-passenger paratransit vehicle. Each vehicle was tested for different combinations of tire types, including highway tires, snow tires, studded-siped tires, highway three-rib tires, all-season tires, and snow-siped tires. Tests of winter traction performance evaluated stopping distance, starting traction, hill climbing, cornering, and controllability. For similar tire combinations and surface conditions, the tested transit and paratransit vehicles had different traction performance. Results indicate that winter traction performance is significantly influenced by vehicle type, tire combination, and road surface (compacted snow or ice). Research findings and recommendations for tire combinations best suited for winter traction are presented.

Effect of test method on winter traction measurements

Traction on winter surfaces was measured using three instrumented vehicles, each designed to measure traction for a different purpose: vehicle mobility research (CRREL instrumented vehicle), commercial tire testing (Uniroyal-Goodrich traction tester), and airport runway safety (Saab friction tester). The traction measured with each method is comparable but there are systematic differences due to the effects of the surface materials and test and analysis techniques. This comparison serves as the basis for collaboration between the various traction testing communities and illustrates the need for well documented, standard test and analysis procedures for traction testing and evaluation.

A Motor for Winter Traction

A Motor for Winter Traction