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.

Vulcanization kinetic of styrene–butadiene rubber by sulfur/TBBS

Abstract: Torque curves, measured with a moving die rheometer at temperatures between 413 and 473 K, were used to characterize the vulcanization of styrene–butadiene rubber with different cure systems based on sulfur and TBBS (N-t-butyl-2-benzothiazole sulfenamide). Several compounds were prepared varying the amount of sulfur and accelerator between 0.5 and 2.5 phr in the formulation. By means of normalized torque curves, the kinetic of cure of these samples was evaluated considering the model of isothermal curing proposed by Kamal and Sourour. In this frame, the parameters of the kinetic model were obtained. The effect of the amount of sulfur and accelerator in the compound on the kinetic parameters was investigated and a maximum of the rate parameter k for the compound with formulation with 1.0 phr of sulfur and 2.0 phr of accelerator was found. A marked decrease in the activation energy of the cure process of the elastomer was observed at higher levels of TBBS in the compound. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 35–41, 2006

Stress relaxation and differential dynamic modulus of carbon black-filled styrene-butadiene rubber in large shearing deformations

Abstract: Combined measurements of shear stress relaxation and differential dynamic storage and loss shear moduli G′ and G″ have been made on styrene-butadiene rubber (type 1502) containing 50 phr N299 carbon black and 10 phr Sundex 790 oil, both cured and uncured, and compared with similar measurements on the cured and uncured gum rubber. The range of temperature was −22.5° to 63°C, and of static shear strain 0.01 to 0.40; the maximum oscillatory shear strain was about 0.005 and the frequency was usually 0.64 Hz. Dynamic measurements of G′ and G″ with no superposed static strain and stress relaxation measurements at small strains on the filled samples could be reduced by frequency-temperature superposition with αT shift factors that were somewhat larger than those that applied to the raw or crosslinked gum. At about 0.6 Hz, the filler increased the storage modulus by about a factor of 5 for the cured sample and about 10 for the uncured; the moduli for the cured and uncured filled samples were almost ident...

Influence of the silica content on rheological behaviour and cure characteristics of silica‐filled styrene–butadiene rubber compounds

Abstract: Rheological behaviour and cure characteristics of silica-filled styrene–butadiene rubber (SBR) compounds and SBR compounds filled with both silica and carbon black with different silica contents were investigated. Rheocurves of the time versus the torque of the compounds showed specific trends with the silica content. For the compounds with low silica content (less than 50 phr), the torque decreased immediately after the steep increase at the initial point of the rheocurve and then increased very slowly. For the compounds with high silica content (more than 50 phr), the rheographs showed two minimum torque points; the torque decreased immediately after the steep increase at the start point of the rheocurve and then increased sharply before reaching the second minimum point. This can be explained by the strong filler–filler interaction of silica. The minimum torque of the compound increased slightly with an increase of the silica content up to 50 phr silica content and then increased appreciably. For the silica-filled compounds, cure times of the t02, t40, and t90 became shorter with an increase of the filler content. For the compounds filled with both silica and carbon black (total filler content of 80 phr), the cure times became longer with an increase of the silica content ratio. © 2001 Society of Chemical Industry

Properties of Random and Block Copolymers of Butadiene and Styrene. III. Three Sequence Styrene-Butadiene-Styrene Block Polymers

Abstract: In butadiene styrene copolymers containing long block sequences chain segments associate with like segments to form a two phase structure. Properties of such polymers are dependent not only on composition and molecular weight but also on block sequence along the chain. Polymers containing two or more polystyrene blocks per molecule form networks and exhibit elastomeric properties in the uncured state resembling those of filler reinforced vulcanizates. This behavior is shown both by linear styrene-butadiene-styrene elastomers and multichain block copolymers branched in the polybutadiene blocks. A prominent loss tangent peak was observed around —40° C for the multichain polymers. Stress strain following prestretching and stress relaxation measurements indicate some shifting of polystyrene associations during stretching. Tensile strength is reduced by increasing temperature and addition of plasticizers. Reinforcement by polystyrene domains in vulcanized block copolymers is evident from tensile stren...