Emulsion Styrene-butadiene Rubber Research Articles

Use of vegetable oils as an alternate to naphthenic oil for extension of emulsion styrene butadiene rubber

Various petroleum based mineral oils like Distillate Aromatic Extract (DAE), Treated Distillate Aromatic Extract (TDAE), Residual Aromatic Extract (RAE) and Naphthenic oils are used for extension of emulsion polymerized Styrene Butadiene Rubber (E-SBR). Vegetable oils are alternate to these petroleum oil from sustainability point of view as vegetable oils have no Polycyclic Aromatic (PCA) content. They improve abrasion resistance leads to less rubber particulates spread in the environment and reduce rolling resistance leads to lower fuel consumption. However, introduction of few vegetable oils leads to slow down the cure reaction due to high unsaturation to saturation ratio. Presence of high fatty acid content in vegetable oils help in better rubber-filler interaction. In the present research, vegetable origin oils as such without any modification (Decas, Palmolein, Groundnut, Soybean, Mustard and Coconut) extended Styrene Butadiene Rubber (OE-SBR) were characterized in standard American Society for Testing and Materials (ASTM) compound recipe for various processing, different vulcanizate and other performance properties. Curative’s dosages were adjusted in the recipe of vegetable oil extended SBR’s to achieve the 300% modulus value like naphthenic oil. Vegetable oil extended Emulsion Styrene Butadiene Rubber (E-SBR) grades (Prepared with Palmolein and Coconut oils) were showing comparable rheometric and stress-strain properties, high reinforcement index (around 5%), better rubber-filler interaction parameter (around 12%), better abrasion resistance (around 23%) and comparable tanδ value @0°, 30° and 60°C as compared to naphthenic oil extended SBR based compound.

To explore extension of emulsion styrene butadiene rubber with modified vegetable oils

To explore extension of emulsion styrene butadiene rubber with modified vegetable oils

Wet Friction of Rubbers Containing DAE or TDAE Process Oil in ESBR and ESBR/BR Blends

AbstractThe inevitable need to replace conventional high aromatic process oils with new safe ones has made it critically important to investigate the extent of tire wet grip modification by process oils’ aromatic content. Here, direct measurement of wet friction is conducted on emulsion styrene butadiene rubber (ESBR) and ESBR/butadiene rubber (BR) rubber blends containing either safe treated distillate aromatic extract (TDAE) or the conventional distillate aromatic extract (DAE) oils. Interestingly, the results reveal that the wet coefficient of friction for rubbers with TDAE is comparable or even better than rubbers with the DAE. This stands in contrast with previous predictions founded on indirect methods such as the values of loss factor tan δ at 0°C. Analysis of temperature dependent dynamic properties exhibits similar values of tan δ at 0°C for two oil types; however, a higher level of loss tangent for TDAE is found near the glass transition temperature. It is hypothesized that the frequency of loading imposed by the microtexture of the concrete counterface may have dictated the temperature range in which the TDAE can surpass the DAE in terms of the wet grip performance. The difference in the wet grip of rubbers having two oils is more pronounced for the ESBR/BR blend system.

Effect of polyethylenimine on properties of emulsion styrene butadiene rubber/butadiene rubber blends

The purpose of this study was to evaluate the effect of polyethylenimine (PEI) on the properties of emulsion styrene butadiene rubber (ESBR)/butadiene rubber (BR) blends. PEI with molecular weight (Mw) of 800, 2,000, 25,000, and 270,000 g/mol with various ratios was successfully incorporated into ESBR/BR blends via rubber compounding method. Study showed almost 100% decrease in scorch time, ts2 in lower Mw PEI (800 and 2000 g/mol), compared to higher Mw PEI (25,000 and 270,000 g/mol) in ESBR/BR blends. PEI incorporated ESBR/BR blends showed an overall improvement in terms of tensile strength. Lower Mw PEI induced better tensile strength with an optimum value at 1.22 MPa, while higher Mw PEI induced better tear strength and self-healing ability. Incorporation of 5 phr PEI 270,000 g/mol in the blend successfully achieved the optimum self-healing efficiency of 71.5% at 160°C for 1 h. Phase separation occurred between higher Mw viscous PEI with rubber matrix at crack region to promote thermal self-healing. PEI molecules were found to be accumulated and assembled on the interface of the rubber chain from scanning electron microscopy (SEM) images. It was suggested weak physical bond interaction such as Van der Waals holding both rubber chains and PEI together, without any changes in the rubber chain backbone.

Impact of Placement of Aminopropyl Triethoxy Silane and Tetraethoxy Silicate on SSBR Chains: Analysis of Rolling Resistance, Wet Grip, and Abrasion Resistance

Solution styrene-butadiene rubber (SBR) and silica filler have attracted a significant attention because of their superior properties in cured rubber mixtures used in automobile tire industry. One of the challenges ahead of using these materials is the hard dispersion of silica with its polar surface in SBR nonpolar rubber. In the present study, the synthesis of styrene-butadiene rubber by solution polymerization method with polymer chain modification using copolymer functionalization was performed. For this purpose, two materials, namely, aminopropyl triethoxy silane (APTES) and tetraethoxy silicate (TEOS), were employed to improve the silica dispersion in the mixture. The results of postsynthesis structural tests show the successful placement of functional groups on the polymer chain. The results of mechanical, dynamic, and imaging analyses of the cured mixtures showed an improvement in the APTES-containing samples rolling resistance, wet surface grip, and abrasion resistance by 39%, 18%, and 17%, respectively, due to having stronger physical and chemical bonds with silica and also the usage of end agents in the polymer chain. The samples containing TEOS had also better results than the conventional SBR rubber. In addition, a sample containing emulsion styrene-butadiene rubber was prepared to compare its properties with those of the solution SBR. Another SBR sample containing silane coupling agent was also prepared to investigate its performance compared to that of the agents placed on the polymer chain. The abrasion resistance, rolling resistance, and wet grip of the coupling agent containing sample showed 2%, 10%, and 30% improvement, respectively, which were very close to those of the sample containing the TEOS agent. In this work, various techniques including, rheometry, wear, rolling, hardness, bound rubber content, dynamic mechanical thermal analysis (DMTA), and field emission scanning electron microscopy (FE-SEM) were employed to analyze the synthesized rubber.

Water-Soluble Elastomeric Carboxymethyl Chitosan as an Efficient Binder for Si Anodes of Lithium Ion Batteries.

The binder acts a pivotal part in determining the mechanical and electrochemical performances of lithium-ion battery electrodes. Herein, a series of water-soluble Si anode binders based on carboxymethyl chitosan (C-Cs) and styrene-butadiene rubber (SBR) is developed. Water-soluble C-Cs and aqueous emulsion SBR solution are mixed to form C-Cs/SBR binders. The physical properties of the modified Si electrode are investigated through electrolyte swelling test, peeling test, and scanning electron microscopy. The mechanical strength provided to Cu foils and active substances by the C-Cs/SBR binder is higher than that produced by C-Cs. This performance can effectively reduce the stress/strain caused by the drastic volume change of the Si anodes during repeated uses and improve the electrochemical property of lithium-ion batteries. The initial thicknesses of the Si electrodes with polyvinylidene fluoride, C-Cs, and C-Cs/SBR20 binders are approximately 7.1, 7.2, and 6.9 µm, respectively. After 100 cycles, their initial thicknesses increase to 11.2, 12.4, and 7.2 µm and correspond to expansions of 57.8%, 72.2%, and 4.3%, respectively. The discharge capacity of Si electrodes containing C-Cs/SBR20 binder reaches to 1340 mAh·g-1 when the current density is 4 A·g-1, and reserves to be 1020 mAh·g-1 after undergoing 400 cycles of repeated use at 500 mA·g-1.

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.

Investigation of the process of latex coagulation by cationic surfactants

In the articlethe estimation of coagulating ability using cationic electrolytes is shown.It was found that in the case of using low molecular weight cationic electrolyte, the completeness of the release of rubber from latex is achieved at their consumption of 20–30 kg/t of rubber. A feature of the behavior of cationic surfactants in the latex coagulation has been established. It is shown that the consumption of cationic surfactants corresponds to the consumption of polymer cationic electrolytes. Also, a hypothesis was put forwardthatcationic surfactants violate the aggregate stability of latex systems and the mechanism of action, which is basedon the interaction of cationic surfactant micelles with latex globules carrying anionic surfactants on the surfaceis proposed.The use of cationic surfactants can eliminate the use of sodium chloride in the industry of separating emulsion styrene-butadiene rubber from latex, as well as solve some environmental problems.The final stage of theinvestigationwas to determinethe parametersof rubber compounds and vulcanizates based on the rubber. These rubbers, rubber compounds and vulcanizates correspond to standard parameters.

Trinseo will sell rubber business to Synthos

Another longtime synthetic rubber producer is exiting the business. The styrenic polymer maker Trinseo has agreed to sell its synthetic rubber unit to Polish competitor Synthos for $491 million, including about $42 million in pension liabilities. The Trinseo business had sales of $320 million last year. The unit’s manufacturing, R&D, and most of its 440 employees are in Schkopau, Germany. Two-thirds of the business’s sales come from solution-polymerized styrene-butadiene rubber (SSBR), a premium rubber used in fuel-efficient tires. Trinseo also makes emulsion styrene-butadiene rubber. The transaction is the second recent strategic move for Trinseo. Earlier this month, the US company completed the $1.4 billion purchase of Arkema’s polymethyl methacrylate business . Through the two deals, Trinseo is hoping for stronger, and more stable, profits. Synthos, which has annual sales of roughly $2 billion, makes a slate of synthetic rubbers similar to Trinseo’s. The company says the acquisition will broaden its

Synthesis of Functionalized Styrene Butadiene Rubber and Its Applications in SBR–Silica Composites for High Performance Tire Applications

Styrene butadiene rubber (SBR) is commonly synthesized from 1,3-butadiene and styrene monomers via two ubiquitous synthetic pathways, by emulsion (ESBR) and solution (SSBR) processes. Emulsion SBR ...

Effect of Reversible Addition-Fragmentation Transfer Emulsion Styrene Butadiene Rubber (RAFT ESBR) on the Properties of Carbon Black-Filled Compounds.

Tread is an important component that directly affects the performance of passenger car radial (PCR) tires. Styrene-butadiene rubber (SBR) is mainly used for tire tread and it includes solution styrene-butadiene rubber (SSBR) and emulsion styrene-butadiene rubber (ESBR). Although SSBR is mainly used, the manufacturing process for SSBR is more challenging than ESBR, which is environmentally friendly, but has the disadvantage of a broad molecular weight distribution. To overcome this, a reversible addition-fragmentation radical transfer (RAFT) polymerization technique is used in ESBR polymerization. An environmentally friendly RAFT ESBR with a narrow dispersity can be polymerized. Here, carbon black-filled compounds were manufactured while using RAFT ESBR, and their properties were compared to ESBR. The analysis showed a low crosslink density of RAFT ESBR, due to the high polysulfide crosslink structure. We manufactured a carbon black-filled compound with the same crosslink density and structure as the ESBR carbon black-filled compound, and the effect of the dispersity of the base polymer was investigated. RAFT ESBR showed 9% better abrasion resistance and 29% better fuel efficiency than ESBR, according to the analysis of the data. The narrow dispersity can reduce energy loss and positively influence the abrasion resistance and fuel efficiency.

Deep insight into interaction mechanisms between ESBR and silica modified by different silane coupling agents

AbstractIn this study, the interaction mechanisms of different silane coupling agents on the mechanical properties, dynamic viscoelastic properties, and rheological properties of emulsion styrene‐butadiene rubber (ESBR)/silica composites were investigated. It is found that the comprehensive performances are improved by the addition of silane coupling agents and the optimal performance is exhibited in ESBR filled with 50 phr modified silica. Moreover, with the addition of the bis‐(3‐triethoxysilylpropyl)‐tetrasulfide modified silica, the wet skid resistance of composites is significantly enhanced by 14.0%, whereas by the addition of 3‐octanoylthio‐1‐propyltriethoxysilane modified silica, the rolling resistance is remarkably reduced by 19.6% and the processing safety is improved. It can be attributed to the increased bound rubber contents induced by the enhanced interactions between the modified silica and rubber matrix characterized by rheological properties. Furthermore, it is pointed out that the second layer bound rubber plays a dominant role in the improved properties of the composites.

Effect of Calcium Chloride as a Coagulant on the Properties of ESBR/Silica Wet Masterbatch Compound.

When designing rubber compounds for high-performance tires, increasing the silica content can improve the wet traction performance but decreases the fuel efficiency. This trade-off relation makes it difficult to improve the two factors simultaneously. One approach is the development of silica wet masterbatch (WMB) technology for producing compounds containing a high silica content with good dispersion. The technology involves a step to mix surface-modified silica and rubber latex. The technique requires a coagulant to break up the micelles of the rubber latex and cause the surface-modified silica and the rubber molecules to co-coagulate due to van der Waals forces. In this study, the effect of coagulant type on the characteristics of silica surface, and the mechanical properties of the emulsion styrene-butadiene rubber (ESBR)/silica WMB compounds was investigated, as well as the abrasion properties and the viscoelastic properties of the vulcanizates.

Synthesis of emulsion styrene butadiene rubber by reversible addition–fragmentation chain transfer polymerization and its properties

ABSTRACTEmulsion polymerization is generally used to synthesize styrene butadiene rubber (SBR), and the molecular weight of this rubber can be easily increased. However, the broad molecular weight distribution (MWD) of SBR increases energy loss and adversely affects the dynamic viscoelastic properties. To overcome this disadvantage, reversible addition–fragmentation chain transfer (RAFT) polymerization, which is a type of living polymerization, is applied to emulsion polymerization for preparing RAFT emulsion SBR (ESBR). The molecular weight and microstructure of RAFT ESBR are compared to those of commercially available ESBR 1502 by gel permeation chromatography and proton nuclear magnetic resonance spectroscopy. The aforementioned two polymers are used to prepare unfilled ESBR compounds, which are compared in terms of key physical properties (abrasion resistance, mechanical properties, and dynamic viscoelastic properties). It is confirmed that various physical properties of RAFT ESBR are improved due to its narrow MWD. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47069.

EFFECTS OF SILANE COUPLING AGENTS ON STRUCTURE AND PROPERTIES OF SILICA-FILLED SILICONE RUBBER/STYRENE BUTADIENE RUBBER COMPOSITES

ABSTRACT Two silane coupling agents, bis-(γ-triethoxysilylpropyl)-tetrasulfide (Si69) and vinyltriethoxysilane (A151), were selected to investigate their effects on structure and properties of silica-filled methyl vinyl silicone rubber (VMQ)/emulsion styrene butadiene rubber (ESBR) composites. The filler–rubber interactions were investigated via bound rubber content and solid-state 1H low-field nuclear magnetic resonance (NMR) spectroscopy, and the mass ratio of VMQ and ESBR in the rubber–filler gel was investigated by thermogravimetric analysis (TGA). The results revealed that VMQ showed a better compatibility with silica than ESBR. Compared with the A151 composite, the composite with Si69 showed the higher content of ESBR in rubber–filler gel, which resulted in the higher bound rubber content and the weaker Payne effect, and it also exhibited higher tensile strength, higher tear strength, better wear resistance, and lower hardness. However, the presence of Si69 reduced the crosslink efficiency of ESBR and completely inhibited the crosslinking of VMQ, which caused the composite to show higher tan δ value at 60 °C than the A151 composite.

EFFECT OF POLYMER CHAIN MODIFICATIONS ON ELASTOMER PROPERTIES

ABSTRACTConsiderable attention is paid to the influence of crosslink density and crosslink structures on the behavior of polymer chains and properties of elastomers. However, a very important parameter seems to be underestimated: the modifications to the polymer chains by curatives, formed by sulfur and fragments of accelerators. We draw attention to this important contribution to performance of spatial networks. The emulsion styrene–butadiene rubber samples, cured with tetramethylthiuram disulfide and sulfur (TMTD/S8) and zinc dialkyl dithiophosphate with sulfur (ZDT/S8), were studied. They were characterized in detail in terms of crosslink density and crosslink structures. Microscale techniques were used to obtain information about the behavior of the polymer chains: positron annihilation lifetime spectroscopy (PALS) to study the free volume structure and differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) to monitor the glass transition process. Properties such as static mechanical performance and thermo-oxidative stability were also evaluated. All of the investigated characteristics were influenced by a combination of crosslink density, crosslink structures, and, to a large extent, by the modifications of the polymer chains. The effect of the modifications is dependent on the amount and the structure of the curatives' molecules. On the basis of the obtained results, the usefulness of the “phr” unit used for calculation of the curatives' amount has been queried. Furthermore, it has been demonstrated that DSC, DMA, and PALS techniques can provide evidence for the presence of the modifications on the polymer chain by curatives.

Effect of the amounts of glycidyl methacrylate on the mechanical and dynamic properties of styrene–butadiene–glycidyl methacrylate terpolymer/silica composites

GMA-SBRs with GMA contents in the range of 0.06–0.71 wt.% were synthesized and used to evaluate the properties of the silica composites for fuel-efficient tires. The chemical structures of the GMA-SBRs were analyzed using Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance (1H NMR), size exclusion chromatography (SEC), and differential scanning calorimetry (DSC). GMA-SBRs can enhance filler–rubber interaction through covalent bond formation between the silica filler and rubber molecules. After compounding, the cure characteristics and mechanical and dynamic properties of the GMA-SBR silica-filled composites were analyzed. The mechanical properties, including the Mooney viscosity, bound rubber, swelling ratio, and moduli, exhibited obvious differences with increasing GMA content. However, the optimum content of GMA in the GMA-SBR, in terms of dynamic properties such as the Payne effect which represents the change in dynamic modulus against the strain to determine the extent of filler flocculation and tan δ at 60 °C representing tire rolling resistance, was ~0.6 wt.%. These results are due to improved silica dispersion, resulting from increased covalent bond formation between GMA-SBR and the silica surface. This approach assists in the determination of functional group contents in functionalized emulsion styrene–butadiene rubber for fuel-efficient tires, leading to a decrease in vehicular greenhouse gas emission.

Filler Wetting in Miscible ESBR/SSBR Blends and Its Effect on Mechanical Properties

The selective wetting behavior of silica in emulsion styrene butadiene rubber (ESBR)/solution styrene butadiene rubber (SSBR) blends is characterized by the wetting concept, which is further developed for filled blends based on miscible rubbers. It is found that not only the chemical rubber–filler affinity but also the topology of the filler surface significantly influences the selective filler wetting in rubber blends. The nanopore structure of the silica surface has been recognized as the main reason for the difference in the wetting behavior of the branched ESBR molecules and linear SSBR molecules. However, the effect of nanopore structure becomes more significant in the presence of silane. It is discussed that the adsorption of silane on silica surface constricts the nanopore to some extent that hinders effectively the space filling of the nanopores by the branched ESBR molecules but not by the linear SSBR molecules. As a result, in silanized ESBR/SSBR blends the dominant wetting of silica surface by the tightly bonded layer of SSBR molecules causes a low-energy dissipation in the rubber–filler interphase. That imparts the low rolling resistance to the blends similar to that of a silica-filled SSBR compound, while the ESBR-rich matrix warrants the good tensile behavior, i.e., good abrasion and wear resistance of the blends.

Functionalized Emulsion Styrene-Butadiene Rubber Containing Diethylaminoethyl Methacrylate for Silica Filled Compounds

In this study, diethylaminoethyl methacrylate-styrene-butadiene terpolymer (DEAEMA-SBR), in which diethyl- aminoethyl methacrylate (DEAEMA) was introduced to the SBR molecule as a third monomer, was synthesized by cold emulsion polymerization. It is expected that amine group introduced to a rubber molecule would improve dispersion of silica by the formation of hydrogen bond (or ionic coupling) between the amine group and silanol groups of silica surface. The chemical structure of DEAEMA-SBR was analyzed using proton nuclear magnetic resonance spectroscopy (H-NMR), Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC) and differential scanning calorime- try (DSC). Then, various properties of DEAEMA-SBR/silica composite such as crosslink density, bound rubber content, abrasion resistance, and mechanical properties were evaluated. As a result, bound rubber content and crosslink density of DEAEMA-SBR/silica compound were higher than those of the SBR 1721 composite. Abrasion resistance and moduli at 300% elongation of the DEAEMA-SBR/silica composite were better than those of SBR 1721 composite due to the high bound rubber content and crosslink density. These results are attributed to high affinity between DEAEMA-SBR and silica. The proposed study suggests that DEAEMA-SBR can help to improve mechanical properties and abrasion resistance of the tire tread part.

Analytical method for determination of butadiene and styrene contents of styrene-butadiene rubber vulcanizates without pretreatment using pyrolysis-gas chromatography/mass spectrometry

Styrene-butadiene rubber (SBR) vulcanizates were prepared using various emulsion SBRs (ESBRs) and solution SBRs (SSBRs) with different microstructures, and were pyrolyzed without pretreatment. Principal pyrolysis products of SBR vulcanizates are butadiene and styrene. Butadiene and styrene contents of the SBR vulcanizates were determined using plots of the relative peak intensity ratio of butadiene/styrene as a function of the molar ratio of butadiene and styrene of the raw SBRs. The peak intensity ratio on the whole increased as the butadiene content increased. The correlation was enhanced by correction with the butadiene/styrene molar ratio of raw SBRs. For the plot of SSBR samples, the correlation was more enhanced by correction with the 1,2-unit/styrene molar ratio of raw SBRs. By using the corrected plots, butadiene and styrene contents of unknown SBR vulcanizates could be determined.