DIN Abrasion Research Articles

Exploring the wear resistance of EPDM‐PAE/SWCNTs composites with a novel perspective of micro‐network structure

AbstractThe effect of single‐walled carbon nanotubes (SWCNTs) on the crosslinking network structure of Ethylene Propylene Diene Monomers (EPDM)—Polyamide elastomers (PAE) is investigated in detail using Hansen Solubility Parameter (HSP) theory. Rheological method and scanning electron microscopy (SEM) are used to investigate the effect of SWCNTs on the molecular chain movement and their interaction with the filler network of EPDM‐PAE. The DIN abrasion test is conducted to obtain the effect of SWCNTs on the wear characteristics of EPDM‐PAE/SWCNTs composites. The linear synergistic relationship between crosslinking density and wear volume indicates that the change in wear properties is contributed by the micro‐network structure. The addition of SWCNTs increases the chemical crosslinking density and improves the wear properties of EPDM‐PAE. However, the decrease in the physical crosslinking density leads to an increase in the degree of internal friction within the network structure, resulting in a decrease in the wear performance. Changes in wear resistance can be related to the micro‐network structure, which provides a novel approach to studying the wear characteristics of high‐performance elastomers. It is also an innovative work based on the network structure to guide the preparation of new wear‐resistant elastomeric materials.

Application of DPG/KH550 modified pyrolysis carbon black in oil and high temperature‐resistant NBR composites

AbstractIn this paper, pyrolysis carbon black (CBp) was introduced into nitrile butadiene rubber (NBR), the effects of the ratio of CBp and carbon black (N326) on the properties of NBR composites were investigated, and the optimal ratio was determined. On this basis, the accelerator DPG, coupling agent KH550 and CBp were modified by ball milling and plasma. The results showed that when the ratio of CBp to N326 was 40:15, the overall properties of NBR composites was better. Compared with the unmodified CBp/NBR composites, the change rate of tensile product, resilience and DIN abrasion of ball milling‐plasma modified CBp/NBR composites in oil environment were reduced by 52.96%, 12.81%, and 27.19%, respectively, and the tear strength after double damage by high temperature and oil bath was increased by 15.63%, which resulted in better oil and high temperature‐resistance. In summary, the ball milling‐plasma combined with DPG/KH550 modified CBp can not only replace N326 carbon black, but also realize the preparation of NBR composites with better oil and high temperature‐resistance.

Application of wet carbon black masterbatch in green mining radial tires

AbstractIn the context of environmental protection and energy consumption reduction, reducing the rolling resistance of mining machinery tires is one of the important methods to achieve the goal of green mining. This study probes the effects of wet mixing with a wet carbon black masterbatch on the rolling resistance and grounding performance of wide‐body vehicle tire treads by investigating the cross‐linking structure, rubber–filler (R–F) interaction force, and physicomechanical properties of the wet mixing rubber compounded with a wet carbon black masterbatch. The results indicate decreases in the maximum torque‐minimum torque difference, cross‐link density, and R–F interaction of the wet mixing rubber and increased filler–filler (F–F) interaction and carbon black dispersion. Meanwhile, the tensile elongation of the wet mixing rubber increases, its DIN abrasion property improves, and its Tanδ decreases at 60°C. A numerical method to estimate tire steady‐state rolling resistance is also developed. Finite element simulation analysis reveals that the steady‐state rolling resistance of the wet mixing rubber is reduced by 7.04% at 100% standard load, and its grounding performance is enhanced. By proposing a method to reduce the rolling resistance of tires, this study also provides a reference for the development of wide‐body vehicle tires.Highlights Explored the filler interaction of wet mixing rubber. Explained the low energy loss of wet mixing rubber. Proposed a new finite element method for calculating tire rolling resistance.

Surface one-step modification of graphene oxide with N-cyclohexylbenzothiazole-2-sulfonamide to enhance the wear resistance of natural rubber/butadiene rubber composites

Natural rubber (NR) and butadiene rubber (BR) composites are frequently used in manufacturing tires and conveyor belts, which are susceptible to severe wear, leading to product failure and significant losses. To enhance the wear resistance of NR/BR composites, we prepared NR/BR composites reinforced with a synergy of N-cyclohexylbenzothiazole-2-sulfonamide surface one-step modified reduced graphene oxide (CZ-rGO) and carbon black N234 (CB) using a latex co-precipitation method. This study explored the effects of GO content and CZ modification on the structure, wear resistance, thermal conductivity, and mechanical properties of the NR/BR blended composites. It showed that adding 2 phr of GO resulted in excellent filler dispersion, significantly improving the tensile strength, elongation at break, tear strength, thermal conductivity, and wear resistance of the composites. The incorporation of CZ-rGO further increased the crosslinking density, vulcanization performance, and filler dispersion with enhanced mechanical properties, thermal conductivity, and wear resistance of the composites. Notably, the DIN abrasion volume was reduced to 77.88 mm³, surpassing the ISO 10247 standard for conveyor belt cover rubber in terms of wear resistance. The wear resistance of NR/BR/CZ-rGO composites is not only significantly higher than that of single NR- or SBR-based rubber composites, but also significantly higher than that of other binary rubber blend composites, and the CZ-rGO filler is simpler in composition and structure and exhibits a more prominent wear enhancement. This work provides guidance for an efficient and environmentally friendly approach to GO surface modification, as well as useful insights for the development of high wear-resistant rubber composites with excellent overall performance.

Novel Design of Eco-Friendly High-Performance Thermoplastic Elastomer Based on Polyurethane and Ground Tire Rubber toward Upcycling of Waste Tires.

Waste rubber tires are an area of global concern in relation to reducing the consumption of petrochemical products and environmental pollution. Herein, eco-friendly high-performance thermoplastic polyurethane (PU) elastomers were successfully in-situ synthesized through the incorporation of ground tire rubber (GTR). The excellent wet-skid resistance of PU/GTR elastomer was achieved by using mixed polycaprolactone polyols with Mn = 1000 g/mol (PCL-1K) and PCL-2K as soft segments. More importantly, an efficient solution to balance the contradiction between dynamic heat build-up and wet-skid resistance in PU/GTR elastomers was that low heat build-up was realized through the limited friction between PU molecular chains, which was achieved with the help of the network structure formed from GTR particles uniformly distributed in the PU matrix. Impressively, the tanδ at 60 °C and the DIN abrasion volume (Δrel) of the optimal PU/GTR elastomer with 59.5% of PCL-1K and 5.0% of GTR were 0.03 and 38.5 mm3, respectively, which are significantly lower than the 0.12 and 158.32 mm3 for pure PU elastomer, indicating that the PU/GTR elastomer possesses extremely low rolling resistance and excellent wear resistance. Meanwhile, the tanδ at 0 °C of the above-mentioned PU/GTR elastomer was 0.92, which is higher than the 0.80 of pure PU elastomer, evidencing the high wet-skid resistance. To some extent, the as-prepared PU/GTR elastomer has effectively solved the "magic triangle" problem in the tire industry. Moreover, this novel research will be expected to make contributions in the upcycling of waste tires.

Building Chemical Interface Layers in Functionalized Graphene Oxide/Rubber Composites to Achieve Enhanced Mechanical Properties and Thermal Control Capability of Tires.

With the rapid development of the transport industry, there is a higher demand for environmental friendliness, durability, and stability of tires. Rubber composites with excellent mechanical properties, abrasion resistance, and low heat generation are very important for the preparation of green tires. In this study, the all-aqueous phase process was initially employed to prepare 2-Amino-5-mercapto-1,3,4-thiadiazole (AZT) functionalized graphene oxide (AGO). Subsequently, modified graphene oxide/silica/natural rubber (AGO/SiO2/NR) composites were obtained through latex blending and hot press vulcanization processes. This method was environmentally friendly and exhibited high modification efficiency. Benefiting from the good dispersion of AGO in the latex and the cross-linking reaction between AGO and NR, AGO/SiO2/NR composites with good dispersion and enhanced interfacial interaction were finally obtained. AGO/SiO2/NR composites showed significantly improved overall performance. Compared to GO/SiO2/NR composites, the tensile strength (28.1 MPa) and tear strength (75.3 N/mm) of the AGO/SiO2/NR composites were significantly increased, while the heat build-up value (10.4 °C) and DIN abrasion volume (74.9 mm3) were significantly reduced. In addition, the steady-state temperature field distribution inside the tire was visualized by ANSYS finite element simulation. The maximum temperature of the prepared AGO/SiO2/NR was reduced by 18.2% compared to that of the GO/SiO2/NR tires. This strategy is expected to provide a new approach for the development of low energy consumption, environmentally friendly, and long-life rubber for tires.

Abrasion Behaviors of Silica-Reinforced Solution Styrene-Butadiene Rubber Compounds Using Different Abrasion Testers.

Solution styrene-butadiene rubber (SSBR) is widely used to improve the properties of tire tread compounds. Tire wear particles (TWPs), which are generated on real roads as vehicles traverse, represent one of significant sources of microplastics. In this study, four SSBR compounds were prepared using two SSBRs with high styrene (STY samples) and 1,2-unit (VIN samples) contents, along with dicyclopentadiene resin. The abrasion behaviors were investigated using four different abrasion testers: cut and chip (CC), Lambourn, DIN, and laboratory abrasion tester (LAT100). The abrasion rates observed in the Lambourn and LAT100 abrasion tests were consistent with each other, but the results of CC and DIN abrasion tests differed from them. The addition of the resin improved the abrasion rate and resulted in the generation of large wear particles. The abrasion rates of STY samples in the Lambourn and LAT100 abrasion tests were lower than those of VIN samples, whereas the values in the CC and DIN abrasion tests were higher than those of VIN samples. The wear particles were predominantly larger than 1000 μm, except for the VIN sample in the DIN abrasion test. However, TWPs > 1000 μm are rarely produced on real roads. The size distributions of wear particles > 1000 μm were 74.0-99.5%, 65.9-93.4%, 7.2-95.1%, and 37.5-83.0% in the CC, Lambourn, DIN, and LAT100 abrasion tests, respectively. The size distributions of wear particles in the Lambourn and LAT100 abrasion tests were broader than those in the other tests, whereas the distributions in the CC abrasion test were narrower. The abrasion patterns and the morphologies and size distributions of wear particles generated by the four abrasion tests varied significantly, attributable to differences in the bound rubber contents, crosslink densities, and tensile properties.

A new method for studying the wear properties of novel wear‐resistant ethylene propylene diene monomers/polyamide elastomer material from the perspective of cross‐linked network structure

AbstractThe cross‐linked network and dynamic viscoelastic properties of ethylene propylene diene monomers (EPDMs)/polyamide elastomer (PAE) were systematically investigated by using equilibrium swelling test and rheological experiment. The filler network formed by single‐walled carbon nanotubes (SWCNTs) in the matrix of EPDM/PAE was studied and discussed in detail by virtue of scanning electron microscopy (SEM). The DIN abrasion test was conducted to derive the cross‐linked network dependence of the frictional wear performance of EPDM. The results indicated that the chemical cross‐linked network was contributed by EPDM and EPDM‐PAE macromolecular chains. In addition, the physical cross‐linked network consisted of the macromolecular entanglement of EPDM‐PAE and the interactions between EPDM/PAE and SWCNTs. Introducing PAE into EPDM matrix resulted in the change of the cross‐linked network, which was considered as the key factor to improve the abrasion resistance of EPDM. Furthermore, the physical cross‐linked network generated by PAE improved the strength of the EPDM matrix prominently. It is an innovative work in exploring the effect of microscopic structure on the macroscopic wear performance of EPDM vulcanizates.Highlights Preparation of EPDM/PAE elastomer using new wear‐resistant material. Analysis on the effect of solubility parameters using Hansen solubility parameter (HSP). Flory–Huggins interaction parameter on three‐dimensional crosslink networks. Microscopic discussion on crosslink‐filling network structure. A new perspective on the discussion of wear resistance mechanism.

Utilization of (Musa Textilis) in Footwear Making in Accordance to Philippine Footwear Federation Industry, Marikina City

Marikina is one of the leading cities in high-grade shoe production. The purpose of this study is to assess the value and quality of footwear made by the researcher from Musa textilis known as abaca in terms of the whole shoe test, bonding, upper material flex of abaca, rub fastness, Martindale abrasion, and din abrasion resistance. The parameters used were the common tests to determine the durability and quality of material for footwear production. This is developmental research in which the author’s target is to create shoes from plant-based material such as abaca (Musa textilis). The developed footwear was also compared to the standard set by the Philippine Footwear Federation, Marikina City Philippines. According to the findings of this study, some plant-based materials can be used for footwear making. The material science of the plant material should also be assessed for durability, flexibility, and compressibility for good and quality footwear. Keywords: Creative Industry, Footwear, Quality, Marikina,

Enhancing silica dispersion and interfacial interaction in styrene butadiene/silica rubber composites by using epoxidized styrene butadiene rubber as interfacial compatibilizer

AbstractIt is usually desired but often challenging to improve the wet traction, and reduce the abrasion and rolling resistance simultaneously in tread rubber, which is referred to as “magic triangle” in tire industry. To fulfill this goal, the filler dispersion and interfacial interaction required to be improved, as they are two essential factors to concurrently govern the ultimate properties of rubber composites. Herein, we synthesized the epoxidized solution polymerized styrene butadiene rubber (ESSBR) with different epoxy level, and used them as interfacial compatibilizer to promote the silica dispersion and silica/rubber interfacial interaction. The epoxy of ESSBR would react with silanol on silica surface and co‐crosslink with SSBR simultaneously, therefore build a strong bridge between rubber matrix and filler. By incorporation of 20 phr of ESSBR‐15% (15% of double bonds on main chain was epoxidized), the wet grip was improved by 40%, and DIN abrasion and rolling resistance were reduced by 38% and 21%, respectively with hardly sacrifice the mechanical properties. We envisage that this study provides an approach for the fabrication of rubber composites with improved silica dispersion and strengthened interfacial interaction.

Effects of microstructures of liquid polyisoprene on the properties of styrene–butadiene rubber/butadiene rubber compounds

AbstractRecently, there has been an increasing interest in liquid rubbers (LRs), which can work as reactive processing aids to replace conventional plasticizers and are used as prepolymers to synthesize novel block copolymers. However, the understanding of effects of their microstructures on the properties of materials is still not sufficient. In this study, liquid 1,4‐polyisoprene (L1,4‐IR) and liquid 3,4‐polyisoprene (L3,4‐IR) with similar molecular weight were selected and mixed with styrene–butadiene rubber (SBR)/butadiene rubber (BR). The effects of microstructures of the LRs on the properties of materials were investigated. L1,4‐IR has more 1,4‐units and fewer 3,4‐units than L3,4‐IR. This gives L1,4‐IR a lower glass transition temperature and much more flexible polymer chains. Vulcanizates containing L1,4‐IR had advantages over samples containing L3,4‐IR, including lower Mooney viscosities, smaller ΔG′ value from 0.3% to 43% of strain, fewer sol fractions, better abrasion resistance and lower values of tan δ at 60 °C. In contrast, high contents of 3,4‐units endow L3,4‐IR with low unsaturation in polymer backbones and high glass transition temperature. Samples containing L3,4‐IR showed higher values of tan δ at 0 °C, better thermal stabilities and excellent DIN abrasion resistance after aging compared to samples with L1,4‐IR. Furthermore, there were no big differences in the mechanical properties of SBR/BR compounds containing L1,4‐IR or L3,4‐IR. The results of this study are of great importance to the practical application of liquid polyisoprene in the rubber industry. © 2023 Society of Industrial Chemistry.

Physical Property of 3D-Printed N-Pointed Star-Shaped Outsole Prepared by FDM 3D Printer Using the Lightweight TPU.

This investigation has shown the feasibility of modulation in physical properties for multiple outsole designs with 3-, 4-, and 6-pointed star-shaped patterns and various thicknesses for 5, 7.5, and 10 mm, which were fabricated with a FDM 3D printer using lightweight TPU filament, where the physical and foot pressure distribution properties were evaluated to confirm the best quality and comfort outsole. Through varying the structural pattern designs in combination with optimal 3D-printing parameters, the physical properties of the TPU LW-3, 4, and 6-PS outsoles were confirmed with enhanced properties along with increased thicknesses. In this study, the morphology images revealed a lower foaming state, a better-fused interlayer, and fewer microvoids in the TPU LW-3, 4, and 6-PS outsole, as the thickness developed, indicating enhanced density and rigidity. The best physical property was confirmed at LW 3-PS-10 with 0.706 specific gravity, 68.3 g weight, 0.232 μs static coefficient and 0.199 μk dynamic coefficient, 236% NSB abrasion, 127 mm3 DIN abrasion, 30% ball drop and 28% pendulum resilience, verifying the most high-quality, safe, and durable prototype. Regarding comfort, the 3-PS-10 also was regarded as comfortable concerning the wearable parts by virtue of its excellent physical properties, as well as its having the largest pressure area and the lower pressure force; meanwhile, the 4PS and 6PS also exhibited similar conditions for different thicknesses. Since not much distinct difference in pressure distribution compared to others was exhibited, it is suggested to explore optimization solutions to update the comfort of the footwear in future research.

Synergistic effect of hybrid montmorillonite materials on the wear resistance of natural rubber/butadiene rubber composites

AbstractThe wear resistance of rubber composite materials has always been the focus of research. The wear resistance will not only affect the service life of products and the safety of equipment, but also have an important impact on the environment. In this work, the preparation and properties of wear‐resistant rubber nanocomposites based on natural rubber (NR) were studied. It is dedicated to improving the wear resistance of NR composites. On this basis, the dispersibility of montmorillonite (MMT) hybrid materials in NR‐based rubber composites was explored. SiO2@MMT, SiO2@MMT@KH560, PDA@GO, and MMT@GO hybrid materials were prepared, and the hybrid materials were applied to the NR/butadiene rubber (NR/BR) system, and NR/BR/hybrid material composite materials were successfully prepared. The results show that the interlayer spacing of MMT in hybrid materials increases, which effectively improves the dispersibility of MMT in rubber matrix. The tensile strength of NR/BR/MMT@GO composite material increased by 12%, the elongation at break increased by 25%, the DIN abrasion decreased by 16.5% compared with the optimum wear rubber formula, and the wear resistance was greatly improved. This work provides a feasible way for the design of functional polymer composites.

High‐speed shear dispersion of MWCNTs assisted by PVP in water and its effective combination with wet‐mixing technology for NR/MWCNTs nanocomposites

AbstractDue to their advantages of low lost, low filling, high‐performance and multifunction, multi‐walled carbon nanotubes (MWCNTs) are ideal filler for preparing high‐performance and multifunctional rubber‐based nanocomposites. However, the poor dispersion of MWCNTs in rubber matrix and their weak interfacial adhesion with rubber matrix limit their industrial applications seriously. Herein, natural rubber (NR)/MWCNTs nanocomposites (NMNCs) with good static and dynamic mechanical properties, electrical and thermal conductivity have been successfully prepared via high‐speed shear dispersion of MWCNTs assisted by polyvinylpyrrolidone in water and its effective combination with rubber wet‐mixing technology, on the basis of the systematic optimization of the most common dispersants and exfoliation methods of carbon nanotubes (CNTs). Compared with NMNCs prepared by traditional dry‐mixing technology (D‐NMNCs), NMNCs prepared by wet‐mixing technology (W‐NMNCs) in this work exhibit better tensile properties, lower compression temperature rise and DIN abrasion, higher electrical and thermal conductivity, better ice and wet‐slip resistance (i.e., the higher loss tangents at −20 and 0°C, respectively), and lower rolling resistance (i.e., the lower loss tangent at 60°C), benefiting from the better dispersion of MWCNTs and the stronger interface interaction of NR‐MWCNTs in W‐NMNCs. In a word, the preparation route of W‐NMNCs developed in this work is very suitable for industrialization and conductive to breaking the insurmountable “Devil's Triangle” problem in tire industry, and W‐NMNCs have potential high‐technology applications in green, antistatic, and heat‐dissipation tires, antistatic conveyors, vibration absorption, and so forth.

Modified nanocrystalline cellulose partially replaced carbon black to reinforce natural rubber composites

AbstractAs a renewable nanomaterials, nanocellulose was generally considered as a green filler for reinforcing polymer. In this study, nanocrystalline cellulose (NCC) isolated from softwood pulp was successfully modified, and the modified nanocrystalline cellulose (m‐NCC) was used to partially replace carbon black (CB) to reinforce natural rubber (NR). Then, the dispersion of m‐NCC in the rubber matrix and the mechanical properties of NR composites were studied. The results showed that the surface modification of NCC improved its dispersion in the NR matrix and the filler‐rubber interfacial interaction. In addition, the m‐NCC partly replaced the CB‐reinforced NR composite with a lower stress at 300% elongation, but the tensile strength, elongation at break, tear strength, and wear resistance of the composites were significantly improved. Besides, the dynamic compression fatigue heat built‐up of the composites in which m‐NCC partially replaced CB was increased, but DIN abrasion and the flex cracking resistance was improved. From these properties, it can be seen that the partial replacement of CB by NCC could basically approach or even achieve the effect of NR composites reinforced by CB, indicating that the NCC had good rubber reinforcement ability.

Improving Study on Wear Resistance and Mechanical Properties of Graphene / Polyurethane Microfoam Composites

Modified reduced graphene oxide (rtgo) was prepared by using γ - isocyanate propyl triethoxysilane (IPTS) as modifier. Graphene / polyurethane nanocomposites were prepared by in-situ polymerization. Graphene / polyurethane composites were characterized by scanning electron microscopy, TGA, DIN abrasion and electronic universal testing machine. The effects of different reaction formulations and graphene addition on the wear resistance and mechanical properties of the composites were studied. The results show that the wear resistance and tear resistance of the composite can be greatly improved after the functional graphene is compounded with polyurethane.

Improving thermal oxidative aging resistance and anti‐reversion property of natural rubber by adding a crosslinking agent

AbstractThe reversion during the curing and the poor thermal oxidative aging resistance of natural rubber are two main problems for its use as a tire tread. To solve the problems, a crosslinking agent, 1,6‐bis(N,N′‐dibenzyl thiocarbamoyl dithio)‐hexane (DBTH), is added into natural rubber/carbon black composites. DBTH can increase the crosslink density, improve the mechanical properties and thermal oxidative aging resistance of the composites. The composites with DBTH can maintain good wet‐skid resistance after thermal oxidative aging. When 0.2 phr DBTH is used to substitute 0.1 phr sulfur and 0.1 phr accelerator in a natural rubber/carbon black composite, the reversion during the curing is reduced and the DIN abrasion decreases by 6%, while the modulus and hardness of the composite keep close to the original. Besides, after thermal oxidative aging at 100°C for 48 h, the rate of change of stress at 300% strain of the composite decreases by 27% with the substitution of DBTH.

LIQUID POLYBUTADIENE EXTENDED ESBR/SILICA WET-MASTERBATCH COMPOSITES FOR IMPROVING ABRASION RESISTANCE AND DYNAMIC PROPERTIES OF TIRE TREAD COMPOUNDS

ABSTRACT Silica wet-masterbatch (WMB) is a well-known technique for manufacturing high-content, highly dispersed silica-filled compounds. Emulsion styrene–butadiene rubber (ESBR)/silica WMB offers several advantages, including excellent silica dispersion and reduced hysteresis, as compared with conventional dry masterbatch (DMB) compound. However, because of the residual emulsifiers in ESBR latex, it can exhibit a decrease in the crosslink density and reductions in its mechanical properties. Moreover, the abrasion resistance cannot be significantly enhanced because of the tradeoff between the improvement in silica dispersion and decrease in crosslink density. Accordingly, the objective of this study was to improve the silica dispersion and abrasion resistance of ESBR/silica WMB compounds by using liquid polybutadiene rubber (LqBR) extended WMB. In detail, three types of LqBR were emulsified to LqBR emulsions, and three types of LqBR extended WMBs were produced by co-coagulating ESBR latex, silane-modified silica, and the LqBR emulsion. A thorough characterization was conducted with emphasis on the silica content, cure characteristics, mechanical properties, abrasion resistance, and dynamic viscoelastic properties. Based on the results, silane-terminated LqBR extended WMB vulcanizate showed a 58% improvement in the 300% modulus, 48% reduced DIN abrasion loss, and a 23% improvement in dynamic properties.

Study on the Use of CTAB-Treated Illite as an Alternative Filler for Natural Rubber

Fillers are indispensable for rubber composites. Carbon black as an efficient reinforcing filler is most widely used in the rubber industry. However, the utilization of nonrenewable feedstock, energy consumption, and footprint for making carbon black lead to the seeking of alternative substitutes for carbon black, which is of great significance. Here in this work, the possibility of illite, a most common mineral in sedimentary rocks, as an alternative filler for natural rubber (NR) is determined. It is found that pristine illite slows the curing rate and decreases the cross-linking density of NR, which results in the inferior performance of NR. This is associated with the weak filler–rubber interaction, which is a vital factor in deciding the performance of rubber composites. Therefore, illite has been modified using hexadecyl trimethyl ammonium bromide (CTAB), a commonly used cation surfactant, for improving the filler–rubber interaction. The thus obtained C-illite is confirmed to be efficient for (i) enhancing the illite–NR interaction, (ii) improving the dispersion of illite in the NR matrix, and (iii) accelerating the curing process of NR with increased cross-linking density. All of these lead to significantly improved mechanical properties and wear resistance of the C-illite/NR composites, e.g., a 71.88% increase of the modulus at 300% strain compared to the pure NR and a 23.79% reduction of the DIN abrasion volume compared to the NR filled with 40 phr pristine illite. This illustrates the high possibility of CTAB-modified illite with an optimal particle size as a promising alternative filler of carbon black for reinforcing rubbers.

Transient abrasion on a rubber sample due to highly dynamic contact conditions

Abrasive processes, primarily the local slip, are the dominant contributor to friction and wear of vehicle tires in service. The time history of forces accompanying acceleration, braking, and cornering in particular, lead constantly to changing contact conditions under the tire. Consequently, a laboratory test taking into account not only surface texture but also tire contact times (in the range of milliseconds) as well as realistic contact forces in a freely controllable temporal sequence is desirable. This paper presents the study of the dynamic contact between a rubber block and the abrasive surface at conditions close to those in a tire footprint. In our case, the test samples are a miniaturized tread block allowing to reproduce the intermittent tire contact including correct contact timings, pressure and friction coefficients in dependence on the driving maneuver to be tested. An analysis and comparison of friction and wear mechanisms for continuous contact and defined contact times is presented surpassing the characterization capabilities of DIN abrasion testers.Two different compounds with a variation of stiffness are examined. The grip and wear rates are analyzed and compared. It is shown that understanding the dominant mechanisms and quantifying tire tread friction and wear in detail require the consideration of realistic transient dynamics of a tire tread block impacting the road at each revolution of the tire.