• Elastomers and Composites
• /
• v.50 no.2
• /
• pp.87-91
• /
• 2015

Cure characteristics of non-oil-extended solution SBR (S-SBR_NO) and oil-extended solution SBR (S-SBR_ EO) compounds reinforced with silica/carbon black were investigated. Minimum and maximum torques of S-SBR_ EO compounds were much smaller than those of S-SBR_NO ones. Delta torques of S-SBR_NO compounds were greater than those of S-SBR_EO ones, and that of S-SBR_NO compound increased with increase in the 1,2-unit content. Optimum cure time ($t_{90}$) of S-SBR compound decreased with increase in the 1,4-unit content, whereas it increased with increase in the 1,2-unit content. Cure rate index of S-SBR compound increased with increase in the 1,4-unit content, whereas it decreased with increase in the 1,2-unit content. Comparing cure characteristics of S-SBR_NO and S-SBR_EO compounds with the same 1,2-unit content, $t_{90}$s of S-SBR_EO compounds were longer than those of S-SBR_NO ones and cure rate indices of S-SBR_EO compounds were smaller than those of S-SBR_NO ones.

• Journal of environmental and Sanitary engineering
• /
• v.12 no.1
• /
• pp.59-68
• /
• 1997

The main purpose of this study was to determine effects of BS-SBR compared with SBR on the removal of soluble organics and sludge separation. In the BS-SBR process, soluble organics were removed by suspended activated sludge as well as biological fixed films and these two processes occurred simultaneously in one tank. The removal efficiency of soluble COD in the BS-SBR, approximately 97% in both 1 and 3-cycle/d was higher than for SBR. The BS-SBR process was very efficient for SS removal. The averaged SS concentration were 4.8 mg/l over the operation period, the daily SS values were consistently below 10 mg/l in both of 1-cycle and 3-cycle a day. The sludge settling characteristics in BS-SBR were totally different from SBR's. The sludge, dark brown, was well flocculated and its floc size was visible larger than the SBR's.

• Elastomers and Composites
• /
• v.59 no.1
• /
• pp.17-21
• /
• 2024

Solution styrene-butadiene rubber (S-SBR) is used to improve the wet grip and rolling resistance properties of tire treads. As blending of SBRs can improve the physical properties of tire treads, we investigated the effects of SBR type and blending ratio on the physical properties. Twelve SBR/SBR biblend composites were prepared using four SBRs with different microstructures. The glass transition temperature (T_g), tanδ at 0℃ (wet grip predictor), and tanδ at 60℃ (rolling resistance predictor) were obtained from dynamic mechanical analysis, and were compared to the expected values obtained from the results of single SBR samples. Most of the SBR/SBR biblend composites exhibited crosslink densities lower than the expected values. The tanδ values at 0℃ and 60℃ of the SBR/SBR blend composites deviated from the expected values, with many of the deviations being disadvantageous. Of the twelve composites, six samples had higher 0℃ tanδ values than the corresponding expected values, and four exhibited superior wet grip properties to those of the SBR single samples. In addition, two of the twelve samples exhibited improved rolling resistance properties as compared with the single SBR samples. Finally, four samples exhibited lower T_g values than expected, and the T_g of one composite was lower than those of the single SBR samples.

• International Journal of Concrete Structures and Materials
• /
• v.7 no.4
• /
• pp.295-301
• /
• 2013

This paper deals with the interfacial effects of silica fume (SF) and styrene-butadiene rubber (SBR) on compressive strength of concrete. Analyzing the compressive strength results of 32 concrete mixes performed over two water-binder ratios (0.35, 0.45), four percentages replacement of SF (0, 5, 7.5, and 10 %) and four percentages of SBR (0, 5, 10, and 15 %) were investigated. The results of the experiments were showed that in 5 % of SBR, compressive strength rises slightly, but when the polymer/binder materials ratio increases, compressive strength of concrete decreases. A mathematical model based on Abrams' law has been proposed for evaluation strength of SF-SBR concretes. The proposed model provides the opportunity to predict the compressive strength based on time of curing in water (t), and water, SF and SBR to binder materials ratios that they are shown with (w/b), (s) and (p).This understanding model might serve as useful guides for commixture concrete admixtures containing of SF and SBR. The accuracy of the proposed model is investigated. Good agreements between them are observed.

• Elastomers and Composites
• /
• v.42 no.3
• /
• pp.143-150
• /
• 2007

Hardness of rubbery materials, which is important for dimensional stability and product performance, was investigated upon temperature change in this study. A newly developed IRHD (International Rubber Hardness Degree) tester was used to measure the hardness changes of NR and SBR specimens at various temperatures and the hardness values were compared with the Young's modulus. The harness and Young's modulus of NR and SBR showed an abrupt change near the glass transition temperatures. The hardness and Young's modulus were increased by increasing temperature due to the increased random chain conformation of molecules. The effect of temperature on hardness and Young's modulus of NR and SBR specimens filled with carbon black and silica was decreased by increasing filler content.

• Elastomers and Composites
• /
• v.49 no.2
• /
• pp.103-109
• /
• 2014

Blends of emulsion SBR (E-SBR) and solution SBR (S-SBR) were prepared, and their microstructures (styrene, 1,2-unit, cis-1,4-unit, and trans-1,4-unit contents) were analyzed by Fourier transform infrared spectroscopy (FTIR) with transmittance mode. Method to measure absorbance by valley-to-valley baseline (TV) is objectively reasonable, but has a demerit which peak intensity of the cis-1,4-unit cannot be correctly measured. In order to obtain information for the four microstructures including cis-1,4-unit, measurement methods without correction (TM) and correction to 99% transmittance (TB) were compared to the TV method. Results obtained by the TB method were closer to those obtained by the TV one than those obtained by the TM. The microstructures were determined from the absorbances obtained by the TM and TB methods according to the ISO/FDIS 21561:2005(E). Variations of the styrene, 1,2-unit, and trans-1,4-unit contents with the blend ratio of E-SBR/S-SBR showed relatively good linearities, and there was no big difference between results obtained by the TM and TB methods. Variations of the cis-1,4-unit content with the blend ratio absolutely did not show linearities irrespective of the TM and TB methods.

• Elastomers and Composites
• /
• v.33 no.4
• /
• pp.231-237
• /
• 1998

In order to investigate the physical properties of rubber blend compound, this experiment was carried out on the cure rate, loss tangent, reinforcement and abrasion properties of S-SBR (solution styrene-butadiene rubber) blends containing silane coupled silica and E-SBR (emulsion styrene-butadiene rubber) blends containing carbon black as a model compound. E-SBR blend showed the highest total bound rubber(TBR), while S-SBR blends showed constant TBR level regardless of rubber type. Rapid cure rate was achieved when the styrene and vinyl content of rubber microstructure decreased and TBR content of rubber compounds increased. The modulus as the index of rubber reinforcement showed the linear relation with TBR content. The large amount of PICO loss was observed when the styrene and vinyl content of rubber microstructure increased, while the small amount of PICO loss was observed when the ratio of bu-tadiene increased in the S-SBR blends with silane copuled silica. The high loss tangent at $0^{\circ}C$, the low loss tangent at $60^{\circ}C$, and the large difference of loss tangent were shown in the S-SBR blends with high styrene content compared to E-SBR blend.

• Elastomers and Composites
• /
• v.39 no.4
• /
• pp.263-273
• /
• 2004

The effects of zinc surfactant (ZB) on the bis(triethoxysilylpropyl)disulfide (TESPD)-silica mixture in natural rubber (NR) and solution butadiene-co-styrene rubber(S-SBR) were compared with respect to their rheological property, processability, physical properties, and silica dispersion. In the NR compound, addition of the ZB increased the reversion resistance time (T-2), the tensile modulus, and the BO time; however, lowered the viscosity, the HBU, and tans values. In the S-SBR copound, addition of the ZB increased the $tan{\delta}$ values while lowered the T-2, the tensile modulus the BO time, the viscosity, and the HBU of the compound. In the NR compounds, addition of the ZB significantly increased the processability and mechanical property. However, in the S-SBR compounds, it improved the processability the mechanical property was not improved.

• Elastomers and Composites
• /
• v.45 no.2
• /
• pp.112-121
• /
• 2010

In this study, styrene butadiene rubber(SBR)/organoclay nanocomposites were manufactured using the latex method with 3-aminopropyltriethoxysilane(APTES) as a modifier. The X-ray diffraction(XRD), transmission electron microscopy(TEM) images, Fourier transform infrared(FTIR) spectroscopy, swelling ratio and mechanical properties were measured in order to study the interaction between filler and rubber according to the mixing temperature in the internal mixer. In the case of SBR/APTES-MMT compounds, the dispersion of the silicates within the rubber matrix was enhanced, and thereby, the mechanical properties were improved. The characteristic bands of Si-O-C in APTES disappeared after hydrolysis reaction in the MMT-suspension solution and the peak of hydroxyl group was increased. Therefore the formation of chemical bonds between the hydroxyl group generated from APTES on the silicate surface and the ethoxy group of bis(triethoxysilylpropyl) tetrasulfide(TESPT) was possible. Consequently, the 300% modulus of SBR/APTES-MMT compounds was further improved in the case of using TESPT as a coupling agent. However, the silanization reaction between APTES and TESPT was not affected significantly according to the increase of mixing temperature in the internal mixer.

• Environmental Engineering Research
• /
• v.19 no.4
• /
• pp.395-399
• /
• 2014

Operation characteristics of the sequencing batch reactor (SBR) process with electro-flotation (EF) as a solid liquid separation method (EF-SBR) were investigated. EF-SBR process showed excellent solid-liquid separation performance which enabled to separate biosolids from liquid phase within 30 min and to extend cyclic reaction time. Although influent organic loading rate was increased stepwise from 5 to 15 g COD/day, food to microorganisms (F/M) ratio could be maintained about 0.3 g COD/g VSS/day in EF-SBR because biomass concentration could be easily controlled at desired level by EF. However, it was impossible to increase biomass concentration at the same level in control SBR (C-SBR) process because solid-liquid separation by gravity settling showed a limitation at higher mixed liquor suspended solids (MLSS) concentration with 60 min of settling time. Total chemical oxygen demand (TCOD) removal efficiency of EF-SBR process was not decreased although influent organic loading rate became 3 times higher than initial value. However, it was seriously deteriorated in C-SBR process after increasing the rate over 10 g COD/day, which was accounted for insufficient organic removal by relatively higher food to microorganisms (F/M) ratio as well as biosolids wash-out by a limitation of gravity sedimentation.