• Elastomers and Composites
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• v.33 no.3
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• pp.149-158
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• 1998

SBR latex, polyurethane latex and epoxy latex were separately mixed with polyvinyl acetate emulsion. The various physical properties were examined for the mixtures. Epoxy mixtures gave a transparent film. Both polyurethane and SBR mixtures showed opaque film with high viscosity. In SBR and polyurethane increase in hardness was dependent on the evaporation rate of water, but in epoxy it was dependent on the degrees of crosslink. Epoxy's showed excellent water-resistance. SBR showed a good flexural strength and impact strength. When vinyl acetate emulsion was mixed with less than 10% latex paper tube showed the ductile fracture, but over latex content 20%, it showed the brittle fracture.

• Elastomers and Composites
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• v.47 no.1
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• pp.54-64
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• 2012

Acrylonitrile was introduced in the emulsion SBR to increase compatibility between silica and rubber. AN-SBR/silica compounds showed faster vulcanization time and higher delta torque values than SBR 1721/silica compounds because interaction between nitrile group of AN-SBR and silanol group on the silica surface could make hydrogen bond that prevented adsorption of the accelerator on the silica surface, which improved the vulcanization reaction efficiency and enhanced the degree of crosslinking. AN-SBR/silica compound showed higher values in minimum torque than SBR 1721/silica compound during the vulcanization because AN-SBR has higher molecular weight than SBR 1721 in the raw material. When PEG was added to the SBR 1721 and AN-SBR compounds, vulcanization time was faster than SBR 1721 and AN-SBR compounds without PEG because PEG has a large number of ether linkages which show high compatibility with silanol group on the silica surface that prevented the adsorption of the accelerator and the ingredients on the silica surface, which improved the vulcanization reaction efficiency. In the mechanical properties, AN-SBR compounds showed higher modulus values at 100%, 300% than SBR 1721 compounds because interaction between nitrile group of AN-SBR and silanol group on the silica surface enhanced the degree of crosslinking. In the dynamic properties, AN-SBR compounds showed lower tan ${\delta}$ values at $0^{\circ}C$ than SBR 1721 compounds in accordance with the $T_g$ values. AN-SBR compounds showed lower tan ${\delta}$ values at $60^{\circ}C$ than SBR 1721 compounds because interaction between acrylonitrile and silica caused strong filler-rubber interaction that induced low energy dissipation by the filler-filler interaction.

• Elastomers and Composites
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• v.50 no.2
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• pp.110-118
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• 2015

In this study, diethylaminoethyl methacrylate-styrene-butadiene terpolymer (DEAEMA-SBR), in which diethylaminoethyl 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 calorimetry (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.

• Elastomers and Composites
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• v.34 no.5
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• pp.414-422
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• 1999

SBR, polyurethane and epoxy latex were separately blended with ethylene-vinyl acetate(EVA) emulsion In $0{\sim}50%$. EVA emulsion was not reacted with latexes in liquid phase and mixtures had good stroage stability. The viscosity of cement mixtures was elevated to 20,000cps in $0.5{\sim}2.0$ hours by mixing. The mixtures mixed with pigment represented high viscosity and showed higher viscosity as time goes by. Mixtures had higher hardness with mixing SBR than mixing epoxy or urethane. The hardness was suddenly increased over cement content 30%. showed pencil hardness $H{\sim}2H$ in $50{\sim}60%$. The increase of hardness in high solids was depended upon not only the condensation of latexs but also the coagulation and adhesion of cement particle.

• Elastomers and Composites
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• v.54 no.4
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• pp.335-344
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• 2019

In this work, styrene butadiene rubber (SBR) and styrene butadiene styrene (SBS) were used to modify asphalt, resulting in SBR- and SBS-modified asphalt, respectively. The two modified asphalts were emulsified with a nonionic emulsifier (Span 60) and cationic emulsifiers (ID, DDA) and their phase stabilization was investigated via particle size, Zeta potential, and flow behavior analysis. With increasing amount of the mixed emulsifier, the particle size decreased, leading to an increase in viscosity. The shear thinning behaviors and Zeta potential values ranging from 35-65 mV were determined and remained considerably stable. In addition, the adhesion strength and compression strength of the SBR-and SBS-modified asphalt emulsion were evaluated via surface free energy examination. The remarkable adhesion and compression strengths were estimated when 5 phr ID and 6 phr DDA were added to the emulsified asphalt modified with SBR and SBS. Therefore ID and DDA, the two cationic surfactants, played significant roles in improving the dispersion and interfacial adhesion strength, resulting in the improved adhesion and compression strength of the emulsified asphalts modified with SBR and SBS.

• Elastomers and Composites
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• v.33 no.5
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• pp.324-334
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• 1998

SBR, polyurethane, acryl and epoxy latex were seperately mixed with ethylene-vinylacetate emulsion(EVA) in the range of $0{\sim}50%$ (wt.% ). For the mixtures, the various physical properties were examined. The viscosity of mixtures was mainly influenced by compatability with EVA emulsion, was decreased within 20% (wt.% ) of latex content, and showed the similar values over 20% (wt.% ) of latex content. The workable time of cement mixtures was mainly depended on the reactivity with cement. The formation of film could be only within $30{\sim}40$ minutes from mixing cement. The tack-free time of mixtures was influenced by the sorts of resin and the quantity of cement. The slow order of tack-free time was epoxy mixtures>SBR mixtures>urethane mixtures>acryl mixtures. The pencil hardness of mixtures was $4B{\sim}2H$, represented higher value in cement mixtures than in emulsion state.

• Elastomers and Composites
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• v.33 no.2
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• pp.83-92
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• 1998

SBR latex, polyurethane latex and epoxy latex were mixed with polyvinyl acetate emulsion in 0~15% (wt.%). For the mixtures, the viscous properties were examined. The viscosity was influenced by the dispersed phase and the chain structures of polymer, and decreased with the rising of temperatures. The viscosity was increased with mixing of epoxy latex, but decreased with addition of SBR latex or polyurethane latex. Thixotropic index was influenced on the size of micelle and hydrogen bond. The thixotropic index was increased with mixing of epoxy latex or polyurethane latex within 5%, but keep up equality over that. The thixotropic index was decreased with mixing of SBR latex within 5%, but keep up equality over that. The relative viscosity were influenced on the activity of molecule and the interference of dispersed phases, was increased with the rising of temperatures. The relative viscosity was decreased with mixing of epoxy latex, but increased with mixing of SBR latex or polyurethane latex.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.10a
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• pp.84-92
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• 1996

The flexural and compressive strengths of polymer-modified mortars containing FRP wastes were investigated. The specimens of polymer-modified mortars containing FRP mortat were perpared by using styrene-butadiene rubber(SBR) latex, ethylene-vinyl acetate(EVA) emulsion and polyacrylic ester(PAE) emulsion with various FRP-sand ratios(10, 20, 30, 40, 50wt%). The compressive and flexural strengths of polymer-mokified mortars containing FRP wastes were decreased with an increase of FRP-sand ratio. But the compressive and flexural strengths of PAE polymer-modified mortar were more improved than OPC, whereas those of SBR and EVA polymer-modified mortars containing FRP wastes were decreased than OPC.

• Applied Chemistry for Engineering
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• v.5 no.5
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• pp.786-794
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• 1994

The strength and durability of polymer-cement mortars were investigated. The specimens of polymer-cement mortar were prepared by using styrene-butadiene rubber(SBR) latex, ethylene-vinyl acetate(EVA) emulsion and polyacrylic ester(PAE) emulsion with various polymer-cement ratios(5, 10, 15, 20wt%). For the evaluation of durability of polymer-cement mortars, freezing-thawing, acid resistance and heat resistance tests were conducted. With an increase of polymer-cement ratio, the frost resistance of polymer-cement mortars was greatly improved, but acid and heat resistance were deteriorated. The compressive and flexural strengths of SBR polymer-cement mortars were improved with an increase of polymer-cement ratio, whereas those of EVA and PAE polymer-cement mortars reached maximum value at polymer-cement ratio of 10wt%.

• Elastomers and Composites
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• v.35 no.3
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• pp.196-204
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• 2000

SBR, polyurethane, acryl and epoxy latex were separately mixed with ethylene -vinylacetate emulsion(EVA) in the range of $0{\sim}50wt%$. For the mixtures, the various physical properties such as defoamerability, mechanical property, and water resistance were experimentally examined. The excellent defoamer was BYK-021 and the appropriate use of it was 0.3 phr for the total components. The shrinkage of compounds was influenced by the compatability of resins and the formation of voids. The mechanical properties was related to the cohesive force of resin particles, the coagulation of cement particles and the co-bonding of resin particles with cement particles. Mixing latex separately showed better properties then non-mixing in the shrinkage ratio, flexural strength, adhesive strength, and impact strength. The water resistance of composites mixed with cement was worse than that of EVA resin.