Styrene-butadiene

About: Styrene-butadiene is a research topic. Over the lifetime, 5568 publications have been published within this topic receiving 62099 citations. The topic is also known as: styrene-butadiene rubber & SBR.

Mechanism of aggregate formation in simplified industrial silica styrene-butadiene nanocomposites: effect of chain mass and grafting on rheology and structure.

Abstract: The formation of aggregates in simplified industrial styrene–butadiene nanocomposites with silica filler has been studied using a recent model based on a combination of electron microscopy, computer simulations, and small-angle X-ray scattering. The influence of the chain mass (40 to 280 kg mol−1, PI < 1.1), which sets the linear rheology of the samples, was investigated for a low (9.5 vol%) and high (19 vol%) silica volume fraction. 50% of the chains bear a single graftable end-group, and it is shown that the (chain-mass dependent) grafting density is the structure-determining parameter. A model unifying all available data on this system is proposed and used to determine a critical aggregate grafting density. The latter is found to be closely related to the mushroom-to-brush transition of the grafted layer. To our best knowledge, this is the first comprehensive evidence for the control of the complex nanoparticle aggregate structure in nanocomposites of industrial relevance by the physical parameters of the grafted layer.

Characterization of soy protein/styrene–butadiene rubber composites

Abstract: The use of renewable soy protein aggregates as a reinforcement network in Styrene–butadiene rubber composites is investigated by dynamic mechanical method. The rigid nature of dry protein has a high shear elastic modulus of ∼2 GPa and therefore is suitable as a reinforcement phase in rubber composites. The addition of soy protein to the rubber composites generates a significant reinforcement effect. The characterization includes the dynamic mechanical and FTIR studies of the annealing effect on the composite modulus. The increasing elastic modulus with time in the constant temperature experiments indicates the hardening of protein through a mechanism of dehydration and structure change. This is also accompanied by an increase in protein density. The apparent rate of modulus increase during annealing at different elevated temperatures up to 140 °C does not show significant differences. A comparison is also made with rubber composites prepared from an aqueous dispersion of carbon black. The result indicates dry protein composites have higher shear elastic moduli at the same weight fractions of filler.

Wear characteristics of styrene butadiene rubber/natural rubber blends with varying carbon blacks by DIN abrader and mining rock surfaces

Abstract: In this study, nine rubber compounds were produced by varying the proportions of natural rubber (NR), styrene butadiene rubber (SBR), and four different carbon blacks. Tensile and tear properties are enhanced by the addition of intermediate super abrasion furnace (ISAF) N231, and modulus increases for the compounds containing N234 carbon blacks. The wear behavior of the prepared rubber vulcanizates against various rocks, such as, granite, shale, schist, sandstone, coal, and concrete, at 4.4 N normal load and 0.8 m/s relative sliding speed were studied in a specially fabricated experimental setup. The DIN abrasion testing results show good abrasion resistant properties of 70 phr NR and 30 phr SBR with N231 grade ISAF type carbon black. Also, moderate abrasion resistance is found in rubber compound containing 80 phr NR and 20 phr SBR with N234 grade ISAF type of carbon black. Out of the various rock types, the schist and sandstone are observed to be highly abrasive against the prepared rubber compounds. The microscopic examination of the abraded rubber surfaces has indicated the formation of longitudinal grooves against harder rocks and transverse ridges against softer rocks. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

A hot-melt pressure-sensitive adhesive based on styrene-butadiene-styrene rubber. The effect of adhesive composition on the properties

Abstract: Hot-melt pressure-sensitive adhesives based on styrene-butadiene block copolymers with aliphatic and aromatic tackifying resins and plastifying oils have been analyzed. The importance of the resin structure in the compatibility with the block copolymer and the influence of the different paraffinic-naphthenic character of the oil in PSA performance have been shown. Ternary systems with a fixed polymer content (30%) and with variable resin and oil contents show a good miscibility over the whole range of compositions, and only one glass transition temperature was found in each composition. The relationship between chemical composition and bulk performance are expressed in terms of the visco-elastic behavior of the adhesives, measured by DMTA. It has been shown that at a given resin content there is a minimum on tan δ peak vs. temperature, the melt viscosities present a plateau region and the tack strength shows a maximum. An important conclusion is that phase separation is not a requirement for maximum tack; some restricted miscibility is enough, present in a few microdomains of the blend. © 1996 John Wiley & Sons, Inc.

Adhesion of flame-treated polyolefins to styrene butadiene rubber

Abstract: Samples of polyethylene and polypropylene have been submitted to repeated short duration (75 ms) flame treatments, at optimum flaming conditions. Surface energies of untreated and flamed specimens were determined by liquid contact angle measurements. It appears that the surface energy of polyethylene increases much more than that of polypropylene after flame treatment. The flamed polymer surfaces were further examined by electron spectroscopy, Fourier Transform IR spectroscopy and secondary ions mass spectrometry. The adhesion properties of modified polymer surfaces were studied by testing in peel the bonded Styrene Butadiene Rubber/polyolefins assemblies. Scanning electron microscopy (SEM) and water contact angle measurements have been used to observe the locus of failure. Good correlations were obtained between surface energy and adhesion strength, the increase in adhesion strength being particularly important for flamed PE/SBR assemblies. In addition, the peeling in a liquid medium allowed the determin...