Styrene-butadiene Rubber Content Research Articles

Vat photopolymerization of silica reinforced styrene-butadiene rubber elastomeric nanocomposites

Compared to their unfilled counterparts, elastomeric nanocomposites offer tailorable combinations of properties, including improved mechanical properties, increased durability, and enhanced thermal and electrical conductivity. However, the high viscosity caused by the presence of both the high molecular weight elastomer and the inclusion of fillers complicates additive manufacturing (AM) of elastomeric nanocomposites. This is especially challenging in vat photopolymerization (VP) AM, which requires resins that possess low viscosity (< 10 Pa·s) and exhibit sufficient storage modulus (∼ 104 Pa) when photocured. To address this process limitation, the authors have previously demonstrated decoupling the relationship between viscosity and molecular weight via VP of a photocurable composite latex resin. In this approach, a photocurable matrix is photocured as a scaffold around the latex particles, which provides sufficient modulus for the printed "green" part. Following a dehydration post-processing step, the latex particles coalesce to provide the final elastomeric mechanical properties without compromising feature resolution.In this work, the authors explore the effects of the addition of silica nanoparticles (10, 15, and 20 wt.%) on (i) the printability of photocurable styrene-butadiene rubber (SBR) latex resin and (ii) the mechanical properties of the resultant printed composites. The printable photocurable silica-SBR colloidal resin is realized by balancing the viscosity of the resin, the modulus of the cured green body, the silica nanoparticles content for reinforcement, and the high SBR content for elastomeric behavior. Specifically, the photocurable colloidal resin's viscosity is controlled by formulation design, while high silica nanoparticle content in the final part is achieved through evaporation of unreactive diluent. Characterization of the printed SBR nanocomposites with 20 wt.% silica reinforcement elucidated significant enhancements in the tensile strength (53 % increase), Young's modulus (671 % increase), and Shore A hardness (108 % increase) compared to printed SBR without filler reinforcement. To the authors' knowledge, this is the first report of 3D printing rubber nanocomposite using VP.

Quantification of tire wear particles in road dust based on synthetic/natural rubber ratio using pyrolysis-gas chromatography–mass spectrometry across diverse tire types

Increase in road traffic leads to increased concentrations of tire-wear particles (TWPs), a prominent source of microplastics from vehicles, in road dust. These particles can re-enter the atmosphere or move into aquatic ecosystems via runoff, impacting the environment. Consequently, accurately assessing and managing TWP levels in road dust is crucial. However, the ISO method (ISO/TS 20593 and 21396) uses a constant ratio of styrene-butadiene rubber (SBR) to natural rubber (NR) for all tires, disregarding the variability in tire composition across different types and brands. Our study found substantial SBR content (15.7 %) in heavyweight truck tires, traditionally believed to be predominantly NR. We evaluated the SBR/NR content in 15 tire types and proposed a method to more accurately evaluate TWP concentrations in road dust from five different locations. Our findings suggest that the conventional ISO method may underestimate the concentrations of TWP due to its reliance on a static ratio of SBR/NR. This study underscores the necessity for a more flexible approach that can adapt to the variability in SBR and NR content across different tire types. By delineating the limitations inherent in current assessment methods, our research contributes to a more adaptable understanding of TWP concentrations in road dust. This advancement prompts the development of a revised methodology that more accurately reflects the diverse compositions of tire rubber in environmental samples.

Evaluation of styrene butadiene rubber asphalt modification mechanism and adhesion effect based on molecular simulation

Recycled rubber materials represent an environmentally sustainable option as asphalt modifiers. This research delves into the modification effects of Styrene Butadiene Rubber (SBR) asphalt at varying SBR content levels, employing a blend of molecular simulation techniques and laboratory experimentation. A comprehensive molecular model of SBR-modified asphalt is established, and molecular dynamics simulations are executed to scrutinize the thermodynamic attributes, dipole moments, mechanical characteristics, and adhesion properties inherent to SBR asphalt. The outcomes of this inquiry reveal that SBR exhibits notable compatibility with a majority of asphalt molecules, as evidenced by their dipole moments. The introduction of SBR into the asphalt matrix results in the adsorption of a substantial quantity of lightweight components, fostering the formation of a cross-linked network that bolsters the asphalt's resilience against external deformation forces. Furthermore, in terms of adhesion work, asphalt demonstrates heightened affinity with alkaline aggregates, and SBR serves to augment van der Waals interactions at the asphalt-aggregate interface, thereby amplifying interfacial bonding strength. However, when the content of SBR reaches 30%, some SBR molecules will be aggregated in the asphalt, which will lead to phase separation and affect the stability of the colloid. Therefore, it is recommended that the content of SBR should be limited to about 20% in practical engineering applications. In this work, the modification mechanism of SBR was analyzed at the molecular scale and verified experimentally, and the results provide a theoretical basis for the rational use of recycled SBR powder in asphalt applications.

Effects of crumb rubber and styrene-butadiene rubber additives on the properties of asphalt binder and the Marshall performance properties of asphalt mixtures

The primary aim of this study is to evaluate the impact of incorporating crumb rubber (CR) and styrene-butadiene rubber (SBR) additives, ranging from 0% to 5% by weight of bitumen, on the performance of a bituminous concrete mixture using the wet process. Laboratory experiments, including the Marshall test, were conducted to establish the optimum bitumen content (OBC) for the hot mix. The study focuses on determining the optimal proportions of CR and SBR to achieve maximum strength. The results show that increasing the proportions of both CR and SBR leads to significant improvements in strength, with the maximum stability recorded at 16.14 kN and a flow of 1.23 mm for a mix containing 5% CR and 4% SBR. The findings further suggest an inverse relationship between CR content and strength, while an increasing SBR content enhances strength. Consequently, the optimal proportions for incorporating CR and SBR additives are identified as 5% and 4%, respectively.

Styrene-butadiene rubber patterned current collector for improved Li-ion kinetics of the anode for high energy density lithium-ion batteries

The styrene-butadiene rubber (SBR) binder migration caused by the capillary force-driven solvent evaporation during the drying process results in the concentration gradient of SBR binder in the anode, which deteriorates the adhesion strength at the interface between the anode film and Cu current collector and Li-ion kinetics, respectively. Here, we report SBR patterned Cu current collector (SPC) to overcome problems caused by the SBR binder migration behavior. Pre-patterned SBR strongly adheres to the Cu current collector, which suppresses its migration during the drying process. Homogeneous SBR distribution in the longitudinal direction of the anode improves the adhesion strength and Li-ion kinetics. Enhanced adhesion strength enables the reduction of the SBR content in the anode, which further improves Li-ion kinetics. The anode employing SPC exhibits improved constant current charging capacity retention and cycling stability compared to those of the anode with a pristine Cu current collector.

Development of a Test Method for the Estimation of SBR-BR Blend Ratio in Tyre Tread Formulation and Validating It through Robust Statistical Tools

Blends of synthetic rubbers are widely used by rubber product manufacturing industries depending on the end use and product application. The estimation of individual rubber in blends is an important aspect to characterise the correctness of the mixing process. In tyre industry, Styrene butadiene rubber/Polybutadiene rubber (SBR/BR) blend is commonly used to achieve different performance properties, particularly for passenger car tyre. Out of the different quantitative analysis techniques to characterise the blend, one of the widely used techniques Gas Chromatography-Mass Spectrometry (GC-MS) has been used to develop and later validate a method to quantify the SBR/BR blend ratio. Through this GC-MS technique detection capability is measured, with a minimum limit of detection (LOD) of 5.17% and a limit of quantification (LOQ) of 15.67% Styrene butadiene rubber (SBR) in an SBR-BR vulcanizate. It is observed that the bias percentage is highest in case of a lower SBR content sample, i.e. 11.1% while in the case of other sets, it is varying from (–)1.4% to (+)1.5%. During the recovery study, it is observed that with increasing SBR content, recovery is also improving. All requirements for a successful method validation: Accuracy, precision, selectivity, detection capability, calibration range and robustness have been carried out in this entire work.

Dynamic mechanical properties in natural rubber/styrene‐butadiene rubber blends: The local strain behavior in the glass transition region

AbstractA study of the local strains developed in vulcanized blends of natural rubber (NR) and styrene butadiene rubber (SBR), prepared by solution mixing, is presented. A semi‐EV system based on sulfur and accelerator was used for curing unfilled compounds at 160°C and 170°C. Samples were characterized by dynamic mechanical properties between −80°C and 20°C. Special interest was placed on the glass transition region of the vulcanized immiscible blends, where the NR and SBR phases are rubbery and glassy respectively. From the study of loss modulus, this research demonstrates how the local strain in the NR phase changes as a function of the amount of SBR in the blend. Assuming a coalescence behavior of the SBR glassy phase above a certain concentration, differences in the local stiffness of each phase in the glass transition regime were found. While in the glassy SBR phase the stiffness slightly varies with the NR/SBR content, a notorious increase was obtained in the rubbery NR phase at higher SBR content. The local strain on the NR phase of the blends shows a slight decrease for the samples vulcanized at 170°C compared with those vulcanized at 160°C.

Visualization of styrene-butadiene rubber (SBR) latex and large-scale analysis of the microstructure of lithium-ion battery (LIB) anodes

This study presents a novel method for analyzing binder distribution in a lithium-ion battery (LIB) anode. The developed method is based on scanning electron microscope (SEM) image analysis and can be used to analyze an aqueous styrene-butadiene rubber/carboxymethylated cellulose (SBR/CMC) binder system. The main advantage of this method is that it can provide large-scale cross-sections of multiple samples in a single milling process while maintaining a high-quality cross-section enabling the clear distinction of electrode components. This minimizes the issue of SEM-based analysis in the selection of a representative analysis area. The sample preparation and image acquisition processes were optimized to obtain high-quality images, and image processing procedures were developed for quantitative analysis. Osmium tetroxide (OsO4) staining and resin embedding enabled us to achieve a smooth two-dimensional (2D) cross-section with a clear distinction of the electrode components. The milling process enabled us to produce high-quality large-scale cross-sections similar to those prepared by ion beam milling methods. It was verified that our developed method is reliable in determining the SBR content and porosity. The developed method was used to analyze the SBR distribution and pore structure of anode layers prepared at various drying temperatures.

Impact of γ-irradiation and SBR content in the compatibility of aminated (PVC/LLDPE)/ZnO for improving their AC conductivity and oil removal

In some cases, blends containing PVC and LLDPE show low compatibility. Adding styrene-butadiene rubber to the PVC/LLDPE mixtures leads to a noticeable increase in tensile strength and compatibility of the blends. Also, an improvement in tensile strength is observed after incorporating SBR compatibilizer resulting in entirely different gamma irradiation doses. Without a compatibilizer, the mixture exhibits a distributed PVC and LLDPE phase with variable sizes and shapes; even a sizable portion of the domains resemble droplets. Styrene butadiene rubber (SBR) and gamma radiation make mixtures of (PVC/LLDPE) more compatible. The SEM study of the blends demonstrated that adding the compatibilizer resulted in finer blend morphologies with less roughness. At the same time, gamma irradiation reduced this droplet and gave a more smooth surface. Poly(vinyl chloride) (PVC) was chemically modified with four different amino compounds, including ethylene diamine (EDA), aniline (An), p-anisidine (pA) and dimethyl aniline (DMA) for improving the electric conductivity and oil removal capability of the blend polymer. All ionomers were prepared by nucleophilic substitution in a solvent/non-solvent system under mild conditions. This work novelty shows a sustainable route for producing oil adsorption materials by recycling plastic waste. After the amination process of poly(vinyl chloride) the oil adsorption was significantly enhanced.

Investigation of Manufacturing Strategies for Advanced Silicon/Graphite Composite Anodes for Lithium-Ion Cells

Due to the advancing electrification in mobility, the production capacity of cells with high power and energy density needs to be increased, while a reduction in production costs is to be aspired. For the gravimetric energy density, 350 to 400 Wh/kg are defined as a goal from the European Union for the so-called cell generation 3b, which is to be achieved by approximately 2025. For this type of next generation lithium-ion batteries volumetric energy densities of about 750 Wh/L are targeted. For this purpose, novel anode materials with increased specific capacities have to be applied. Silicon is a promising candidate for this application, since it has a theoretical specific capacity of 3579 mAh/g at room temperature, which is one order of magnitude higher compared to the state-of-the-art graphite anode material (372 mAh/g). While silicon is lithiated, a volume change of about 280 % can be observed, which reduces the mechanical integrity of the electrodes and leads to a strong decrease in capacity and therefore a short cell lifetime. To overcome this issue, several approaches are pursued, whereof the most promising candidate to fulfil the requirements of scalability for industrial applications is the utilization of silicon nanoparticles. The establishment of a water-based slurry preparation process for silicon/graphite composite anodes with a fine dispersion of the silicon nanoparticles is crucial. Several manufacturing routes are investigated with special focus on the scalability, processability, spatial distribution of the binder, silicon and graphite active material as well as on the performance during galvanostatic cycling.Fur this purpose, different binder configurations are applied, where the amount as well as the degree of polymerization and substitution of sodium carboxymethylcellulose (Na-CMC) and the content of styrene butadiene rubber (SBR) are of interest. Additionally, the destruction of the silicon nanoparticle agglomerates, which can only be achieved with high intensity impact realized by a ball mill, is separated from the whole mixing process. Therefore, the destruction of the graphite active material by the ball milling process is reduced. A dry mixing process of the graphite and the conductive carbon black is investigated as well.The implementation of additional porosity with a laser patterning process was also proven to be effective to increase the cell lifetime of silicon/graphite composite electrodes. Therefore, an ultra-short pulsed laser source is applied to generate line patterns in the composite material. This significantly improves the wetting of the electrode with liquid electrolyte, but also reduces the mechanical stress inside the electrode due to the increased artificial porosity available for volume expansion which finally leads to an immense impact on cell lifetime.

Erosive wear characteristics of styrene butadiene rubber and silicon dioxide-filled wood–plastic composites

In order to improve the erosive wear resistance of wood-plastic composites, the bamboo fibers/high-density polyethylene composites containing a mixture of styrene butadiene rubber (SBR) and silicon dioxide (SiO2) with different content of SBR + SiO2 and different ratio of SBR/SiO2 were prepared through compression molding. The response surface methodology with 14 treatments was adopted to obtain the composites with optimized formulations. The optimized composites were subjected to the erosive wear test conducted by using the swirling water jet technique with different shooting distances and erosive durations ranging from 0.5 to 1.5 cm and from 60 to 180 s, respectively. And the morphology and chemical element analysis measured by scanning electron microscopy equipped with energy dispersive spectroscopy, the chemical structure obtained by Fourier transform infrared were used to further investigate the erosive wear mechanism. The results revealed that the composites containing 6.85 g mixture (46.7 wt% SBR and 53.3 wt% SiO2) and 6.78 g mixture (48.9 wt% SBR and 51.1 wt% SiO2) per 100 g matrix exhibited maximum hardness and impact strength, respectively. The above two filled composites all presented higher erosive wear resistance than the composites without a mixture, the weight loss and volume loss were only one-half and one-third that of the composites without the mixture. However, there was no significant difference between the erosive wear resistance of those two composites. Analysis of the erosive micrographs, element distribution, and chemical structure of the erosive surfaces showed that the erosive wear of the composites primarily resulted in pulverization of the fibers, brittle fracture of the matrix, and increase in the oxygen content and number of hydroxyl groups.

Mechanical characterization of low modulus polymer-modified calcium-silicate-hydrate (C–S–H) binder

Calcium-silicate-hydrate (C–S–H) represents a key microstructural phase that governs the mechanical properties of concrete at a large scale. Defects in the C–S–H phase are also responsible for the poor ductility and low tensile strength of concrete. Manipulating the microstructure of C–S–H can lead to new cementitious materials with improved structural performance. This paper presents an experimental investigation aiming to characterize a new synthetic polymer-modified synthetic calcium-silicate-hydrate (C–S–H)/styrene-butadiene rubber (SBR) binder. The new C–S–H/SBR binder is produced by calcining calcium carbonate and mixing this with fumed silica (SiO2), deionized water and SBR. Mechanical, physical, chemical and microstructural characterization was conducted to measure the properties of new hardened C–S–H binder. Results from the experimental investigation demonstrate the ability to engineer a new C–S–H binder with low elastic modulus and improved toughness and bond strength by controlling the SBR content and method of C–S–H synthesis. The new binder suggests the possible development of a new family of low-modulus silica-polymer binders that might fit many engineering applications such as cementing oil and gas wells.

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

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%.

Effects of Styrene Butadiene Rubber on Physical and Mechanical Properties of Kenaf Core Fiber Reinforced Polypropylene Composites

In this research, the kenaf core fiber (KCF) reinforced polypropylene (PP) in the presence of styrene butadiene rubber (SBR) were melted blending with PP using Brabender internal mixer. The composites then fabricated using compression molding to form a sheet of PP and KCF reinforced PP (KCFPP) composites. Pure polypropylene (PP) matrix was used to serve as control whilst SBR was functionalized as impact modifier to improve the toughness properties of PP. The mechanical properties were determined by tensile test using Universal Testing Machine (UTM) according to ASTM D5803. The results show that the increment in SBR content has given an improvement in impact related properties (elongation at break) but at the expenses of strength and modulus properties.

Effects of SAE and SBR on properties of rapid hardening repair mortar

Calcium sulfoaluminate (CSA) cement is helpful to solve the problems of road and bridge maintenance as the cementitious material in rapid repair mortar. However, this repair mortar still has some disadvantages as low flexural strength and poor toughness during application. The effects of styrene acrylate ester (SAE) and styrene–butadiene rubber (SBR) latexes on rheological properties of CSA paste and mechanical properties of repair mortar were investigated, especially the toughness. Both SBR and SAE can reduce the fluidity loss rate and prolong the setting time, increase the flexural strength and bending toughness but decrease the compressive strength. The flexural strength and bending toughness reached the highest when the content of SBR was 8%, or when the content of SAE was12%. The effect of SAE on the toughness of repair mortar was more obvious. Continuous polymer film formed with the addition of SAE and SBR polymers. This film was conducive to the improvement of internal defects in the mortar and enabled uniform transfer of stress in the specimen, effectively suppressing the development of cracks. In addition, the polymer film formed by SAE was loose. Thus, the film had a slight effect on the distribution of the original hydration products in CSA cement. However, the continuous and dense polymer film formed by SBR had a certain effect on the continuous distribution of cement hydration products.

Novel Hybrid Biomass Anti-Aging Filler for Styrene-Butadiene Rubber Composites with Antioxidative and Reinforcing Properties.

Antioxidants are normally utilized to extend the service life of polymers due to the strong reducibility of the phenolic hydroxyl group of the hindered phenol structure. Inspired by this characteristic, we have introduced green tea polyphenol (TP) supported on a silica surface containing considerable phenolic hydroxyl groups to obtain a novel biomass anti-aging filler (BAF, denoted as silica-s-TP) to reinforce and improve the anti-aging property of rubber composites. The applying of silica-s-TP to enhance the thermal-oxidative stability and ultraviolet light (UV) aging resistance of styrene-butadiene rubber (SBR) was evaluated. The hybrid biomass anti-aging filler could not only uniformly disperse in the rubber matrix, giving rise to the excellent mechanical properties, but also enhance the properties of thermal-oxidative stability and UV aging resistance with the increasing silica-s-TP content of SBR distinctly. This study provides a mild and environmentally friendly strategy to prepare the functional biomass filler, which could be applied as not only a reinforcement filler but also an anti-aging additive in “green rubber”.

Gas products generation mechanism during co-pyrolysis of styrene-butadiene rubber and natural rubber

In this study, reaction molecular dynamics were combined with experiments to gain in-depth understanding of the gaseous pyrolysis products generation mechanism and optimal paths during natural rubber (NR), styrene-butadiene rubber (SBR) and mixed rubbers (NR-SBR) for effective recovery of waste rubber. The results show that the pyrolysis temperature of NR increases gradually with SBR addition. The monomers produced during the initial stage of SBR pyrolysis are mainly 1,3-butadiene and styrene, in which the energy barriers of the formed H and CH2=CH in styrene are higher than those in 1,3-butadiene, and during further pyrolysis the main gas products are H2 and CH4. During co-pyrolysis of NR-SBR, the reaction paths show that increasing H2 yield and decreasing CH4 yield take place easily as SBR content rises. By contrast to pyrolysis of NR, the path of generating CH2=CH in SBR is more difficult while that of CH2=CH abstracting H occurred easily, leading to first enhancement in produced CH2=CH2 followed by a decline. Fixed bed experiments and gas chromatography (GC) analysis identify the main gas products of the three rubbers (NR, SBR, NR-SBR)as H2, CH4 and CH2=CH2 and the change of yield caused by the increase of SBR content are consistent with the simulation results.

EFFECT OF POLYMER/CEMENT RATIO AND CURING REGIME ON POLYMER MODIFIED MORTAR PROPERTIES

ABSTRACT Cement is the most consumed building material in the world. However, cement manufacture is responsible for 5–7% of the world CO2 emissions. In this paper, cement was partially replaced by styrene-butadiene rubber (SBR) polymeric latex in order to reduce cement consumption. Besides, effects of SBR addition on the strength and physical properties of plain mortar exposed to three different curing regimes are presented. Three different curing regimes were applied to the 40 × 40 × 160 mm prismatic mortar specimens: (I): Specimens were cured in water until the test age (CW), (II): after demoulding, specimens were immersed in water for 2 days and kept in ambient temperature until the time of the test (2DWA) and (III) involved 2 days of water curing followed by 1 day in an oven at 50°C and subsequentely placing in ambient temperature until the test time (2W1OA). Results showed that combining 2 days of water curing followed by ambient temperature curing (2DWA) along with 3% SBR polymer content showed good performance in terms of compressive strength, water absorption and void content. Moreover, a good performance in terms of flexural strength was observed by combining 2W1OA curing regime with 2% SBR content. However, the detrimental effect of water curing regime (CW) in terms of compressive and flexural strength was also observed with the increase of SBR ratio.

Experimental investigation of effect of PP/SBR polymer blends on the moisture resistance and rutting performance of asphalt mixtures

Prevention of surface failure in flexible pavements and application of durable asphalt mixtures leads to the design of a high-quality pavements and improvement in safety and confidence of drivers. Moisture susceptibility, or stripping, is a type of failure which results in the separation of binder and aggregate in asphalt mixtures, and consequently intensifies other kinds of failures including fatigue and rutting. Improvement in properties of asphalt mixtures’ components can minimize the failures of road pavements. In such a context, binder modification with polymers is known as an effective method which enhance mixtures’ strengths against common damages. In This study, a blend of two inexpensive polymers has been suggested as binder additive to modify the performance of the asphalt mixtures against moisture. For this purpose, styrene-butadiene-rubber (SBR) and polypropylene (PP) are combined by different ratios 70:30, 50:50 and 30:70, then each of polymer blends were added in 60–70 binder with 3, 4 and 5% of the weight of the binder. Since the styrene butadiene styrene (SBS) polymer is a well-known and effective additive in term of moisture susceptibility of flexible pavements, mixtures containing modified binders with blended polymer (SBR/PP) were compared to mixtures containing SBS modified bitumen with 4% and 5% polymer content. In all samples, 1.5% Nanoclay (by mass) was utilized to increase the stability of polymers in the binder. To evaluate the moisture susceptibility and permanent deformation, Texas boiling test, Marshall stability, Resilient modulus, Indirect tensile strength (ITS) and Dynamic creep tests were carried out on mixture samples modified by polymer blends, mixtures modified by SBS and also an unmodified sample (control mixture). As the experimental results show, by increasing SBR content in asphalt mixtures, the performance of the samples against moisture failure has been improved. Furthermore, among all tested samples, the asphalt mixture containing 5% polymer blends with 70% of SBR Shows the best performence which can be introduced as an economical alternative for mixture with high dosage of SBS.

Mechanical properties of styrene butadiene rubber toughened graphene reinforced polystyrene

In this study, styrene butadiene rubber was used for toughened polystyre/graphene nanoplatelets (PS/GNP) nanocomposites. The objective of this research is to determine the effect of styrene butadiene rubber (SBR) contents on the toughness of PS/GNP nanocomposites. In order to achieve the objectives of the research PS/GNP nanocomposites were prepared with various SBR content styrene butadiene rubber content, while the contents of GNP were fixed at 0.5 wt%. The PS/GNP/SBR nanocomposites were prepared by melt blending technique. Mechanical properties of SBR toughened PS/GNP nanocomposites showed a decrement of toughness and tensile strength with increasing content of SBR. SEM study shows that the rubber dispersed uniformly within the blends with polystyrene nanocomposites. SEM results show that the polystyrene mixed with graphene nanoplatelets (PS/GNP) had the smooth surface compare to samples have toughened with styrene butadiene rubber. The mechanical properties of PS/GNP nanocomposites with contain of 15 wt% of SBR shown the best of toughening effect.