Showing papers on "Styrene-butadiene published in 2019"

Interweaving 3D network binder for high-areal-capacity Si anode through combined hard and soft polymers

Abstract: Si anodes suffer an inherent volume expansion problem. The consensus is that hydrogen bonds in these anodes are preferentially constructed between the binder and Si powder for enhanced adhesion and thus can improve cycling performance. There has been little research done in the field of understanding the contribution of the binder's mechanical properties to performance. Herein, a simple but effective strategy is proposed, combining hard/soft polymer systems, to exploit a robust binder with a 3D interpenetrating binding network (3D-IBN) via an in situ polymerization. The 3D-IBN structure is constructed by interweaving a hard poly(furfuryl alcohol) as the skeleton with a soft polyvinyl alcohol (PVA) as the filler, buffering the dramatic volume change of the Si anode. The resulting Si anode delivers an areal capacity of >10 mAh cm−2 and enables an energy density of >300 Wh kg−1 in a full lithium-ion battery (LIB) cell. The component of the interweaving binder can be switched to other polymers, such as replacing PVA by thermoplastic polyurethane and styrene butadiene styrene. Such a strategy is also effective for other high-capacity electroactive materials, e.g., Fe2O3 and Sn. This finding offers an alternative approach in designing high-areal-capacity electrodes through combined hard and soft polymer binders for high-energy-density LIBs.

Composition Determination of Rubber Blends by Applying Differential Scanning Calorimetry and SPA-PLS Treatment

Abstract: This paper proposes an innovative approach to determine the composition of natural rubber (NR) and styrene butadiene rubber (SBR) blends from the analysis of the data provided by the differential scanning calorimetry (DSC) technique. DSC registers are post-processed, based on a multivariate chemometric approach, consisting in the application of the successive projections algorithm (SPA) as variable selection algorithm and a further application of the partial least squares (PLS) regression method and the leave-one-out cross-validation algorithm. Results attained by applying this approach are compared with those obtained from mid-infrared spectroscopy since this last method has been widely applied during the last decades. Experimental results summarized in the paper prove that this fast and cost-effective approach is useful to determine the composition of unknown incoming NR/SBR blends.

Improvement of Silica Dispersion in Solution Polymerized Styrene–Butadiene Rubber via Introducing Amino Functional Groups

Abstract: Uniform silica dispersion is vital for achieving high-performance and low-rolling-resistance tires. Though silane coupling agents could improve the dispersion of silica, it would also lead to increasing processing complexity and volatile organic compounds. In the present work, amino-functionalized solution polymerized styrene–butadiene rubber (F-SSBR) were designed and synthesized aiming to form a hydrogen bond between the amino group and hydroxyl group in silica to improve the silica dispersion. In order to study the different effect of F-SSBR with in-chain or end-chain amino groups on silica dispersion, two 1,1-diphenylethylene (DPE) derivatives were introduced into the SSBR molecular chains via living anionic polymerization. Afterward, silica nanoparticles reinforced F-SSBR composites for tire tread were prepared. The effects of the functional groups of SSBR on the microstructure and performance of the composites were investigated. The results revealed that the incorporation of DPE derivatives into the...

Effect of styrene-butadiene rubber latex on the rheological behavior and pore structure of cement paste

Abstract: Styrene-butadiene rubber (SBR) latex is beneficial to the workability of cement-based materials, but the mechanism remains unclear. This study aims to investigate the effect of SBR latex on the rheological property and pore structure of cement paste. The results showed that the fluidity of the modified cement-based material was improved, and a significant linear relation was obtained between the air content and the fluidity of the cement paste. The yield stress and viscosity of the paste decreased with increasing SBR latex content, and the modified cement paste exhibited shear-thinning behavior. In addition, the SBR latex can deteriorate the pore structure of the hardened cement paste at 3 days due to the hydrophobic groups easily trapping the air into the paste. Compared with that of the ordinary Portland cement paste, the number of pores (size range of 0.1 μm–1 μm and 10 μm-200 μm) in the SBR-modified cement paste was clearly increased. However, the lowest porosity was achieved at 28 days, when 2% SBR was used due to the filling effect of the hydration products and polymer particles. The throat/pore ratio and fractal dimension increased with the SBR latex content, illustrating the increasing of ink-bottle pores with a rough surface.

Preparation of carboxylic styrene butadiene rubber/chitosan composites with dense supramolecular network via solution mixing process

Abstract: A novel supramolecular network based on carboxylic styrene butadiene rubber (XSBR) and chitosan (CTS) is prepared through solution mixing process. XSBR molecular chains have strong interactions with extended CTS via the formation of ammonium carboxylates bridging crosslinks and hydrogen bonds, which efficiently prevent extended CTS from reagglomerating. Compared with CTS nanoparticles, unfolded CTS expose more amino and hydroxyl groups to XSBR, which results in a denser and stronger network structure. However, because of the rigidity of CTS molecule, unfolded CTS construct a rigid framing in the supramolecular network, which reduces the extensibility of the XSBR/CTS composites. Interestingly, the solution mixing retains abundant air bubbles in the XSBR/CTS solution, which turns out a porous composite.

Effect of styrene-butadiene rubber and fumed silica nano-filler on the microstructure and mechanical properties of glass fiber reinforced unsaturated polyester resin

Abstract: In this research, the microstructure and mechanical properties of glass fiber reinforced unsaturated polyester (GFRP) composites modified by styrene-butadiene rubber (SBR) and fumed silica were investigated. The fumed silica particles were dispersed uniformly in the nano-scale into the unsaturated polyester resin. Then, it was mixed with SBR and chopped glass fiber by bulk molding compound (BMC) process, and molded by compression molding. A full factorial design and analysis of variance (ANOVA) were utilized to study the effect of factors and their interactions on the mechanical properties. The addition of fumed silica nano-filler improved tensile, flexural and impact strength, tensile and flexural modulus but reduced the elongation at break. On the other hand, adding SBR content decreased flexural strength and modulus and tensile modulus of composites, but, increased elongation at break, impact and tensile strength. Based on optimization results, the SBR with 10 wt% and 3 phr for fumed silica has been selected as the optimum composite formulation providing the best strength-stiffness-toughness balance among the samples.

Enhancing fatigue properties of styrene butadiene rubber composites by improving interface adhesion between coated aramid fibers and matrix

Abstract: This paper details a new method for characterizing the interfacial bonding performance of short-fiber reinforced rubber composites and its correlation with fatigue properties. Meanwhile, the experimental study of interfacial damage during the fatigue process is presented. Aramid fiber (AF) was modified with an aqueous solution of lithium chloride and then coated with butadiene styrene vinyl-pyridine rubber latex (VPL) or maleated polybutadiene liquid rubber (MLPB). Subsequently, the coated AF was introduced into a butadiene styrene rubber (SBR) matrix to fabricate reinforced butadiene styrene rubber/carbon black/aramid fiber (SBR/CB/AF) composites. Atomic force microscopy (AFM) was employed to identify the flexible interface layer of the SBR composites. After 30,000 fatigue cycles, the modulus of the interface layer was obviously reduced to below that of the SBR matrix, which produced hysteresis of the reinforcing effect of AF due to concentrated damage in the interface layer. The relative debonding energy (RDE) is innovatively introduced to characterize the interfacial adhesion performance. A higher RDE value can lead to the interface layer absorbing more deformation work and a longer fatigue life of the composite. SBR reinforced by T-AF/MLPB, with its high modulus interface, has the longest fatigue life, corresponding to the highest RDE value.

Rational design of multifunctional properties for styrene-butadiene rubber reinforced by modified Kevlar nanofibers

Abstract: In this work, a facile and effective approach is developed to obtain the water-dispersible Kevlar nanofibers (KNFs) by modifying KNFs with the assistance of epichlorohydrin (ECH). And the ECH-modified KNFs (m-KNFs) are firstly utilized to prepare styrene–butadiene rubber (SBR)/m-KNFs nanocomposites through latex co-coagulation method. The multifunctional properties of SBR/m-KNFs nanocomposites are thoroughly investigated. It is confirmed that m-KNFs have strong interactions with SBR via π-π stacking, which can generate huge enhancement on the performance of SBR nanocomposites. For example, the tensile strength, tear strength and the maximum decomposition temperature of SBR filled with 7 phr (parts per hundred rubber) m-KNFs are increased by 576%, 202% and 13.1 °C, respectively, compared with those of neat SBR. Meanwhile, the presence of m-KNFs has also improved the dielectric constant of SBR nanocomposites. This work provides a new insight into the fabrication of multifunctional KNFs-based rubber composites.

High-Performance Styrene-Butadiene Rubber Nanocomposites Reinforced by Surface-Modified Cellulose Nanofibers

Abstract: Styrene-butadiene rubber (SBR) is widely used in the tire, footwear, and belt industries. SBR products contain a high content of carbon black, which is hazardous to human health and the environment. The goal of this study is to investigate the potential of using bio-based cellulose nanofibrils (CNFs) as a replacement for carbon black under simulated industrial formula/processing conditions. CNFs were surface-modified using five different reagents to have either -SH or -C=C functional groups grafted onto their surfaces. Vulcanized SBR sheets reinforced with pristine CNFs, and the five functionalized CNFs were prepared and their properties were tested and compared with those of industrial SBR containing carbon black. All the CNFs, pristine or modified, demonstrated higher reinforcing efficiencies (property increase/amount of reinforcement) than carbon black. The modified CNFs showed even higher reinforcing efficiencies than the pristine ones because of the former's better dispersion and stronger interfacial bonding. The -SH and -C=C functional groups reduced the hydrophilicity of CNFs and allowed chemical linkages between CNFs and SBR to be established during vulcanization. Solvent (toluene) resistance of the rubber was also improved after the incorporation of CNFs because of the barrier effect of the nanofibers and the restrained SBR chain mobility. The latter also led to reduced rubber damping. Although CNFs provide much stronger reinforcement than carbon black, going forward, SBR/CNFs/carbon black hybrid nanocomposites can also be developed to offer tailorable property combinations that meet different application requirements.

Giving a Second Opportunity to Tire Waste: An Alternative Path for the Development of Sustainable Self-Healing Styrene–Butadiene Rubber Compounds Overcoming the Magic Triangle of Tires

Abstract: Current regulations demand tires with long lifetime and reduced fuel consumption without sacrificing car safety. However, tire technology still needs to reach a suitable balance between these three indicators. Here, we address them by developing a self-healing tire compound using styrene-butadiene rubber (SBR) as the matrix and reclaimed tire waste as the sustainable filler. The addition of ground tire rubber (GTR) to the matrix simultaneously improved the rolling resistance and maintained both wet grip and healing ability. We provide an in-depth analysis of the healing behavior of the material at a scale close to the relevant molecular processes through a systematic dynamic-mechanical and dielectric analysis. We found that SBR and SBR/GTR compounds show a complete recovery of stiffness and relaxation dynamics after being damaged by cyclic deformation, resulting in a heterogeneous repaired rubber network. This new development could well overcome the so-called magic triangle of tires, which is certainly one of the key objectives of the tire industry.

Application of nano-silica and styrene-butadiene-styrene to improve asphalt mixture self healing

Abstract: Nanoparticles, due to their physical and chemical characteristics, present an inherent potential to improve the performance of bituminous materials. Presently, the technology of producing nanosized particles is evolving, and their application in various aspects of pavement engineering is becoming more cost-effective. Nanosilica, due to its spherical shape, high specific area, very tiny size and higher density compared to bitumen, presents an inherent potential to accelerate molecular randomisation movements, promote bitumen binder flow into microcracks and evolve healing index (HI) of hot mix asphalt (HMA). Moreover, it has been proved that Styrene–Butadiene–Styrene polymer (SBS) promotes fatigue life of HMA and decreases its temperature sensitivity. It would be interesting to know if the addition of nanosilica to modified binder with SBS will promote the total HI and lead to an enhanced HMA life cycle. In this study, the effects of four parameters, most importantly, the effect of the combination ...

Effects of the Nanoclay and Crosslinking Systems on the Mechanical Properties of Ethylene-propylene-diene Monomer/styrene Butadiene Rubber Blends Nanocomposite

Abstract: This paper investigates the effect of nanoclay and crosslinking systems on the cure characteristics, mechanical properties, abrasion resistance, compression set and swelling properties of ethylene-propylene-diene monomer (EPDM)/styrene butadiene rubber (SBR) blends. Nanocomposites were prepared by two-roll mill. In this work, three different crosslinking systems were used, namely, sulphur, dicumyl peroxide and the mixed system consisting of sulphur and peroxide. The mechanical properties such as tensile strength, elongation at break, 100% modulus, hardness, crosslink density and tear strength of the EPDM/SBR nanocomposites were studied. Cure study indicates that nanoclay not only accelerates the curing reactions but also gives rise to a noticeable increase of the torque values, representing crosslinking density of the nanocomposites increases at the existence of nanoclay. The tensile strength and 100% modulus of EPDM/SBR nanocomposites increases with increase in nanoclay content up to 7.5 phr and then decreases for all the different cross-linking system. The elongation at break, hardness, tear strength and compression set increases with increasing content of nanoclay.

Enhanced comprehensive performance of SSBR/BR with self-assembly reduced graphene oxide/silica nanocomposites

Abstract: The dispersion of filler and properties of elastomer composites are always the focus in the rubber researching. In this work, RGO/SiO2 nanocomposites were obtained by self-assembling of silica nanoparticles (SiO2) and reduced graphene oxide (RGO), which were used to manufacture RGO/SiO2-SSBR/BR composites by means of compounding with solution-polymerized styrene butadiene rubber/butadiene rubber (SSBR/BR). The structure and morphology characterization showed that SiO2 nanoparticles were homogeneously distributed on RGO. With the adding of RGO, the mechanical properties were enhanced and the RGO/SiO2-SSBR/BR with 1% weight percentage of RGO possessed the optimal wet skid resistance and rolling resistance compared with commercialized Zeosil 1165 MP highly-dispersed nano-SiO2 (Zeosil 1165 MP)-SSBR/BR (tan δ is 16.8% higher at 0 °C and 50.0% lower at 60 °C). In addition, the heat build-up exhibited considerable decrease with low RGO weight percentage, and wear resistance considerably enhanced. The reinforced integrated performances provide a potential application of RGO/SiO2 for green tires.

Comparative Study of Water-Based LA133 and CMC/SBR Binders for Sulfur Cathode in Advanced Lithium–Sulfur Batteries

Abstract: Two most widely used commercial water-based binders, polyacrylic latex (LA133) and sodium carboxymethyl cellulose/styrene butadiene rubber (CMC/SBR), are utilized for constructing sulfur cathodes t...

Effect of the functional group of silanes on the modification of silica surface and the physical properties of solution styrene-butadiene rubber/silica composites

Abstract: Silica compounds were prepared using non-functionalized solution styrene-butadiene rubber (SSBR) to investigate effect of the functional group of silanes on the silica modification and properties o...

Ionic liquid modified multiwalled carbon nanotube embedded styrene butadiene rubber membranes for the selective removal of toluene from toluene/methanol mixture via pervaporation

Abstract: Present work reports the fabrication of elastomeric membrane based on ionic liquid functionalized multiwalled carbon nanotubes (f-MWCNT) incorporated Styrene butadiene rubber (SBR) for the separation of azeotropic composition of toluene and methanol. The fabricated membranes were characterized by morphological analysis using transmission electron microscopy and glass transition temperature and heat capacity measurements by differential scanning calorimetry. Composite membranes demonstrate impressive separation performance with preferential selectivity towards toluene and 5 phr f-MWCNT loaded membranes was found to show the best result with respect to toluene flux and selectivity. Optimal separation performance with the permeation flux 225% of SBR control membrane and separation factor of 128 (1.6 times of SBR control membrane) is obtained for this membrane. The concurrent optimization of the physical and chemical structures of toluene permeation path on f-MWCNT surface provides the membrane with high-efficiency toluene permeation. Ionic liquid on MWCNT surface confer aromatic pi-pi interaction with toluene molecules leading to greater toluene affinity and higher repellency against methanol. Pervaporation characteristics of the membranes were also strongly influenced by the feed mixture composition. The study confirmed that increasing toluene concentration improved the toluene flux but reduced the separation factor. The experimental pervaporation fluxes were compared with the calculations based on modified Maxwell–Stefan equation. The model allows a good quantitative prediction of experimental flux values.

Dynamic Moduli Mapping of Silica-Filled Styrene─Butadiene Rubber Vulcanizate by Nanorheological Atomic Force Microscopy

Abstract: Atomic force microscopy (AFM) offers nanoscale mapping of materials’ properties. Especially, our modified AFM termed “nanorheological AFM” enables us to measure the accurate frequency-dependent storage and loss moduli and loss tangent over a sixth-order frequency range without any temperature control at nanoscale resolution. These dynamic properties obtained by nanorheological AFM can be compared with those using bulk dynamic mechanical analysis (DMA) measurements. In this paper, we applied this technique to silica-filled styrene–butadiene rubber (SBR) to investigate the nature of the interfacial rubber region existing between a rubber matrix and silica particles at different temperatures. The dynamics properties of the interfacial rubber region were different from those of matrix rubber regions. The master curve obtained by this technique perfectly coincided with that by bulk DMA. Furthermore, it was found that the behavior of bulk loss tangent could be predicted by the contributions from both matrix and...

Utilization of chrome-tanned leather wastes in natural rubber and styrene-butadiene rubber blends

Abstract: Nowadays, the amount of chrome-tanned leather scraps from the leather industry is increasing rapidly due to diminishing interest in their utility in related areas. These kinds of wastes cause considerable negative, environmental effects, and therefore, producers should find new methods of recycling and/or disposal. It is speculated that leather scraps may be a valuable additive in rubber-based materials thanks to their similar elastic properties. In this study, chrome-tanned leather wastes have been incorporated into natural rubber and styrene-butadiene rubber and their blends in various ratios by using a Banbury mixer and two-roll mill, subsequently. Effects of the wastes on rheological, thermal, mechanical, aging, and morphological properties of the blends were investigated. Different penetration ability and distinct cure rates of the two rubbers caused interesting rheological characteristics. Original mechanical properties of styrene-butadiene rubber and its blends were retained after waste incorporation. Furthermore, thermal aging resistance of natural rubber matrix could be improved. The most significant effect of leather particles is the enhancement of the tear strength of all the vulcanizates by shifting the tear mechanism towards the tortuous fracture pathway.

Direct Observation of Carboxymethyl Cellulose and Styrene-Butadiene Rubber Binder Distribution in Practical Graphite Anodes for Li-Ion Batteries.

Abstract: Despite the important role of carboxymethyl cellulose (CMC) and styrene–butadiene rubber (SBR) binders in graphite electrodes for Li-ion batteries, the direct analysis of these binders remains chal...