Showing papers on "Styrene-butadiene published in 1992"
TL;DR: In this paper, a SBS triblock copolymer with a phase-separated morphology of hexagonally packed cylinders of poly(styrene) in a poly(butadiene) matrix was studied by TEM and SAXS.
Abstract: Shear-induced alignment of phase-separated domains was studied by TEM and SAXS in a SBS triblock copolymer with a phase-separated morphology of hexagonally packed cylinders of poly(styrene) in a poly(butadiene) matrix. Starting with an ordered structure, where the cylinders were aligned with a common director throughout the sample, a shear flow perpendicular to this director was found to rotate the cylinder orientation by 90° into the shear direction. At all observed strains, the hexagonal faces preferred to orient parallel to the shear plane
73 citations
TL;DR: Sorption and diffusion of five monocyclic aromatic liquids (three halogenated benzenes, nitrobenzene, and aniline) with five engineering polymers (e.g., polyethylene propylene diene ter-polymer, nitrile butadiene rubber, styrene butadiane rubber, natural rubber, and neoprene) have been investigated in the temperature interval of 25-60°C as discussed by the authors.
Abstract: Sorption and diffusion of five monocyclic aromatic liquids—three halogenated benzenes, nitrobenzene, and aniline—with five engineering polymers—ethylene propylene diene ter-polymer, nitrile butadiene rubber, styrene butadiene rubber, natural rubber, and neoprene—have been investigated in the temperature interval of 25–60°C. Solvent diffusivity into polymer membranes was determined from the immersion/weight gain experiments. Permeability coefficients were also calculated from the diffusion and sorption data. A temperature dependence of sorption and transport was also investigated to estimate the activation parameters. The experimental results and computed quantities were used to study the type of transport mechanism and the nature of polymer-solvent interactions.
38 citations
TL;DR: The effect of grafting modification of the fillers on the formation of bound rubber and its two components is discussed in this article, where two relaxation times are attributed to the occurrence of tightly and loosely bound rubber components.
Abstract: Proton spin–spin relaxation time measurements have been performed at 300 and 400 MHz on bound rubber-filler mixes resulting from the solvent extraction of silica-filled and silicafilled-modified polybutadiene, on the one hand, and of carbon black-filled and carbon blackfilled-modified styrene butadiene rubber, on the other hand. Two relaxation times are observed for all samples. They are ascribed to the occurrence of tightly and loosely bound rubber components, respectively. The effect of the grafting modification of the fillers on the formation of bound rubber and its two components is discussed. © 1992 John Wiley & Sons, Inc.
37 citations
TL;DR: In this paper, the authors investigated the viscoelastic properties of polymers obtained by coalescence of styrene-butadiene (SB) copolymer latices by dynamic micromechanical spectroscopy.
32 citations
TL;DR: In this article, the authors studied the transport behavior of eight esters into six commercial polymer membranes by immersion/weight gain experiments to determine how transport behavior is affected by the choice of the solvent molecules and the chemical structures of the polymer membranes.
Abstract: Sorption and diffusion of eight esters into six commercial polymer membranes have been studied by immersion/weight gain experiments to determine how the transport behavior is affected by the choice of the solvent molecules and the chemical structures of the polymer membranes. The temperature dependence of transport parameters was found to follow the Arrhonius activation theory. It has been proved that the kinetics of equilibrium concentration can be described by the first-order kinetic rate equation. Furthermore, the results of transport parameters have been discussed in terms of the size, shape, and chemical nature of the diffusant molecules.
28 citations
TL;DR: In this article, the hydrosilylation of SBR and NBR using triethylsilane in the presence of RhCl(PPh 3 ) 3 was studied at 110°C in toluene.
Abstract: The hydrosilylation of SBR and NBR using triethylsilane in the presence of RhCl(PPh 3 ) 3 was studied at 110°C in toluene. It was found that the reaction mechanism was markedly influenced by the nature of the functional groups in the polymer chain. In the case of SBR, the reaction occurred via a typical anti-Markovnikov addition leading to a linear adduct. When strong electronegative groups such as nitrile were present (NBR), the addition appeared to occur via a Markovnikov addition mechanism which led to a branched adduct.
26 citations
TL;DR: In this article, the authors show that a concrete with a good air void spacing factor and a low water-cement ratio can be almost as resistant to salt scaling as latex-modified concrete.
Abstract: Freezing and thawing tests in the presence of a 2.4% NaCl solution were carried out on normal concretes and styrene butadiene (SBR) rubber latex concretes in accordance with ASTM C 672. The results indicate that SBR in concrete improves very significantly the resistance of the concrete surface to freezing and thawing in the presence of deicer salts. This improvement depends on the quantity of SBR, the air void spacing factor, and the water/cement ratio. Only 2 of the 9 standard mixtures, but 12 out of the 17 modified concrete mixtures had mass losses lower than 1 kg/sq m at 100 cycles. The results also show that a conventional concrete with a good air-void spacing factor and a low water-cement ratio can be almost as resistant to salt scaling as latex-modified concrete.
25 citations
Patent•
17 Jul 1992
TL;DR: In this article, a method of producing cross-linked polymer modified asphalt or bitumen is described, which includes the steps of combining by agitation polymers chosen from a group consisting of styrene rubber, styrene butadiene rubber, polydiene rubber and polyolefin diene rubber to form a homogeneous mixture.
Abstract: A method of producing cross-linked polymer modified asphalt or bitumen. The method includes the steps of combining by agitation polymers chosen from a group consisting of styrene rubber, styrene butadiene rubber, polydiene rubber and polyolefin diene rubber, 80 to 99% by weight of asphalt or bitumen, with the asphalt or bitumen at temperatures of 130° to 230° C. to form a homogeneous mixture. Thereafter, 0.05 to 2.0% by weight of asphalt of a reactive phenol-aldehyde resin is added to the mixture. The reaction is thereafter completed by continuing agitation of the mixture.
21 citations
TL;DR: In this paper, a theoretical model for the distribution of molecular weight, branching and crosslinking in styrene-butadiene emulsion copolymers is proposed, where the main objective is to compute the instantaneous distributions of primary macroradicals and primary dead chains with zero, one, two or more crosslinks.
20 citations
TL;DR: In this article, the Hildebrand-Scatchard solubility theory was combined with the Flory theory in order to estimate the thermoplastic rubbers at the three different temperatures.
Abstract: Fundamental thermodynamic interaction data for various solvents with two styrene–butadiene–styrene triblock copolymers (Kraton D-1101 and Kraton D-1300X) have been collected by the use of inverse gas chromatography at infinite dilution. Experimental results are presented for nine D-1101/solvent systems and nine D-1300X/solvent systems at 308, 328. and 348 K. Weight-fraction activity coefficients and Flory–Huggins χ interaction parameters have been calculated from the retention volumes. The χ parameter is used as a measure of the strength of interaction and therefore as a guide in the prediction of polymer–solvent compatibility. In addition, partial molar heats of mixing, ΔHm∞, and heats of solution, ΔHs, were determined. The Hildebrand–Scatchard solubility theory was combined with the Flory theory in order to estimate the solubility parameter of the thermoplastic rubbers at the three different temperatures.
17 citations
Journal Article•
TL;DR: In 1990, a survey of modified asphalt test pavements was conducted to examine performance during construction and service while using the various additives on the market as mentioned in this paper, including styrene butadiene rubber (SBR) latex, Styrelf-13, DuPont neoprene latex, polyethylene (Novophalt process), ethylene vinyl acetate (Exxon and DuPont), Solar Laglugel (nylon resin polymer), Gilsonite, asphalt-rubber (tire rubber), Dow polymers (unknown), Plus-Ride (ground tire
Abstract: In 1990, a survey of modified asphalt test pavements was conducted to examine performance during construction and service while using the various additives on the market. Representatives from 14 states, Austria, and Canada were contacted to survey the field performance of more than 30 end-to-end test pavements where one to five asphalt additives, modifiers, or modification processes have been evaluated. States contacted include Alabama, California, Colorado, Indiana, Louisiana, Maine, Minnesota, Montana, New Jersey, Texas, Utah, Vermont, and Virginia. Additives include styrene butadiene rubber (SBR) latex, Styrelf-13 (SBR reacted with asphalt), DuPont neoprene latex, styrene butadiene styrene block copolymer (Shell Kraton), polyethylene (Novophalt process), ethylene vinyl acetate (Exxon and DuPont), Solar Laglugel (nylon resin polymer), Gilsonite, asphalt-rubber (tire rubber), Dow polymers (unknown), Plus-Ride (ground tire rubber replacing aggregate), Microfil-8 (pelletized carbon black with oil), Celite (diatomaceous earth), Chemkrete, hydrated lime, fly ash, Acra 500, and fibers. Most of the results have been collected by telephone and are, therefore, qualitative. Some of those contacted have sent written reports that provide more quantitative data. Unfortunately, many of the test pavements are less than 5 years old and show no differences in performance.
TL;DR: In this paper, the polymer resulting from homogeneous catalytic hydroformylation of styrene-butadiene copolymer was shown to contain an internal aldehyde product as well as an anti-Markovnikov product.
Abstract: The polymer resulting from the homogeneous catalytic hydroformylation of styrene-butadiene copolymer is shown to contain an internal aldehyde product as well as an anti-Markovnikov aldehyde product. No hydrogenation of the polymer was observed under hydroformylation conditions. No unwanted side reactions occurred during the reaction. Kinetic and spectral studies suggest that the active catalytic species is probably HRh(CO) 2 (PPh 3 ) 2 . The kinetic data were found to be useful for optimization of the reaction rate and product distribution.
TL;DR: In this article, the formation of functional groups during the milling of natural rubber, epoxidised natural rubber (ENR), styrene butadiene rubber (SBR), neoprene (CR), and acrylic rubber (AR).
Abstract: Processing operations such as milling, change the chemical structure of rubber. Infrared (IR) spectroscopy and electron spectroscopy for chemical analysis (ESCA) have been used to detect the formation of functional groups during the milling of natural rubber (NR), epoxidised natural rubber (ENR), styrene butadiene rubber (SBR), neoprene (CR), and acrylic rubber (AR). The concentration of carbonyl () groups as detected by IR spectroscopy increases with the time of milling for all the rubbers. The concentration of hydroxyl groups (OH) in NR and ENR also increases during milling. ESCA spectra of the rubbers before and after milling reveal that the peaks are broader for milled rubber, and that the concentration of oxygen is also greater. In the case of ENR, however, the concentration of epoxide rings decreases and that of furan rings increases with the time of milling.
TL;DR: In this paper, the compatibility behavior of epoxidized styrene-butadiene (SB) block copolymers with chlorinated polyethylene at two degrees of chlorination (36 and 48 wt%) and with poly(vinyl chloride) was investigated over the complete composition range.
Patent•
15 Apr 1992
TL;DR: In this paper, tire tread compositions are disclosed wherein the rubber component comprises: i) a first rubber component comprising about 5-15 parts of nitrile-butadiene rubber (NBR) per hundred parts of rubber (phr); ii) a second rubber component consisting about 43-95 phr of styrene butadiene (S-SBR); and iii) a third rubber component including 0-47 phr of high cis polybutadienes (cis BR) rubber.
Abstract: Tire tread compositions are disclosed wherein the rubber component comprises: i) a first rubber component comprising about 5-15 parts of nitrile-butadiene rubber (NBR) per hundred parts of rubber (phr); ii) a second rubber component comprising about 43-95 phr of styrene butadiene rubber (S-SBR); and iii) a third rubber component comprising 0-47 phr of high cis polybutadiene (cis BR) rubber. The compositions may also include suitable amounts of other ingredients such as carbon black, aromatic oil, zinc oxide, stearic acid, sulfur, sulfur donor compounds, sulfur cure accelerators, waxes, antiozonants, etc.
TL;DR: In this paper, the experimental values of thermal conductivity for the entire blend composition are empirically correlated by a single polynomial equation for the above temperature zone in the form of C(T) = A1T + A2T2 − A3T3, where the constants A1, A2 and A3 are functions of composition, F.
TL;DR: In this paper, Fatigue behavior of gum and carbon black filled natural rubber and styrene butadiene rubber vulcanizates has been investigated at constant strain and constant stress at 75° and 125 °C.
Abstract: Fatigue behaviour of gum and carbon black filled natural rubber and styrene butadiene rubber vulcanizates has been investigated at constant strain and constant stress at 75° and 125 °C. Samples swollen in paraffin oil have also been examined. For all the vulcanizates, the cut growth increases with number of cycle. NR vulcanizates show rapid cut growth with increase in filler loading whereas cut growth is slowed for SBR vulcanizates up to 50 phr loading. At 50 phr loading of different types of carbon black (N220, N375, N550 and N660) NR samples display increase in cut growth with an increase in sur face area of carbon black. An opposite trend is shown for SBR sample. The criti cal number of cycles at which the cut growth becomes rapid varies with the nature and loading of filler and temperature. At constant stress however, the cut growth becomes slower with increase in loading. All the above results could be explained with the help of strain energy density and number of flaw sites. Cut growth rate increase...
Patent•
09 Apr 1992
TL;DR: In this article, a polymer/bitumen layer is applied on top of the already applied silicate layer, pref. 1-10 (pref. 3-7) wt.
Abstract: Sealing against water of porous construction surfaces which have been treated with an aq. soln. of an alkaline, water-repelling Si cpd. is effected by applying a polymer/bitumen layer on top of the already applied silicate layer, pref. after the silicate has been air-dried and pref. using a polymer/bitumen contg. 1-10 (pref. 3-7) wt.% of a styrene/butadiene/styrene (SBS) block copolymer which pref. has mol. wt. 60,000 - 120,000. USE/ADVANTAGE - Layers can be applied, even when the silicate underlayer is non-uniform, and an improved sealant effect is achieved, with cracks in the surface being covered over and sealed. (0/0)
TL;DR: In this article, a low-resolution 1H-NMR was used to characterize commercial experimental transparent styrene-butadiene (SB) block copolymers, high impact polystyrene and blends.
TL;DR: The green strength of a gum SBR and two black-filled samples, at twenty-three volume percent filler, have been determined at various strain rates and temperatures as discussed by the authors, indicating that it is largely controlled by chain mobility.
Abstract: The green strengths of a gum SBR and two black-filled samples, at twenty-three volume percent filler, have been determined at various strain rates and temperatures. At higher temperatures, all samples exhibit yielding, followed by strain-softening. The gum exhibits this type of behavior down to −20°C, whereas, filled specimens undergo strain hardening at this temperature. Yield strength increases with decreasing temperature or increasing rate, indicating that it is largely controlled by chain mobility. Yield strengths at various temperatures may be shifted along the rate axis to form mastercurves. The dependence of yield stress on reduced rate is similar for the gum and the composition filled with the large-sized thermal black (N990). Stiffening is reasonably well accounted for by strain and strain-rate amplification, using the well-known Guth—Gold amplification factor. At low reduced rates, the extent of stiffening is substantially greater for samples filled with the much finer furnace black, N1...
Journal Article•
TL;DR: In this article, the first 1 1/2 years of a 5-year study were evaluated, and the results of the first 5 years of the study were reported, showing that no significant long term benefits can be attributed to the use of SBR latex in dense graded asphalt mixtures.
Abstract: Many benefits are attributed to the use of styrene-butadiene rubber (SBR) latex in asphalt concrete pavements. These include decreased temperature susceptibility, increased rut resistance, and increased resistance to stripping. Potential benefits of SBR latex in hot mix asphalt mixtures were evaluated, and the results of the first 1 1/2 years of a 5-year study are reported. Six existing test sites were identified and selected for evaluation. The test sites were located throughout Alabama, and each contained a control mixture and SBR latex modified mixture. Condition surveys were performed at each site to compare performance parameters such as rutting, transverse cracking, raveling, and bleeding. The Alabama Highway Department's pavement management data base provided additional data. The data base was investigated to compare performance of pavements with the department's 416 (control) and 417 (SBR latex modified) surface mixes. The parameters analyzed included mean (rut depth/sqrt ESAL), present serviceability index, friction number, condition rating, and transverse cracking. On the basis of preliminary results, no significant long term benefits can be attributed to the use of SBR latex in dense graded asphalt mixtures. However, further testing is required to verify the results.
Patent•
26 Mar 1992
TL;DR: In this paper, a material for the prodn. of underbody protection film for motor vehicles is presented, which is useful for the above application, by rolling out as a film 0.6-1.3 mm thick, which was then provided with a 0.01-0.05 mm layer of bitumen-compatible hot-melt adhesive (pref.
Abstract: A material (I) for the prodn. of underbody protection film for motor vehicles; (I) contains 30-60 (pref. 38-55) wt. % bitumen, 1-10 (pref. 2.5-7.5) wt. % styrene/butadiene (SB) copolymer, 1-5 (pref. 2.5-3.5) wt. % EVA copolymer and 1-5 (pref. 2-3.5) wt. % rubber flour. (I) also contains balsamic resin and/or paraffin and, as fillers, 1-10 (pref. 2.5-6.5) wt. % unslaked lime, 23-33 (pref. 16-30) wt. % ground slate, 7-13 wt. % mica and 3-12 (pref. 5.5-10) wt. % sepiolite, and the bitumen can be partly or completely replaced by paint coagulate. USE/ADVANTAGE - (I) is useful for the above application, by rolling out as a film 0.6-1.3 (pref. 1) mm thick, which is then provided with a 0.01-0.05 mm layer of bitumen-compatible hot-melt adhesive (pref. EVA copolymer) on the top side and a 0.015-0.05 mm layer of wax (pref. PE or amide wax) on the other side; (I) retains its adhesiveness and plasticity at -40 deg. C, and is stable for 30 mins. at 190 deg. C (claimed). The invention provides an environmentally acceptable material (I) with very good properties on metal surfaces which is able to withstand subsequent painting and stoving. (5pp Dwg.No.0/0)
TL;DR: In this paper, gradual styrene-butadiene rubbers (SBRs) were prepared from linear SBRs of narrow molecular weight distribution synthesized by anionic polymerization.
TL;DR: In this article, the safe operation of the batch emulsion polymerization of Styrene-Butadiene, with all reactants charged at the start, is studied, and simplified kinetic and headspace pressure models are developed.
Abstract: The safe operation of the batch emulsion polymerization of Styrene-Butadiene, with all reactants charged at the start, is studied. In order to assess runaway potential, simplified kinetic and headspace pressure models are developed. Kinetic information is obtained from isothermal reaction runs carried out over wide ranges of temperature (70 to 125°C) and pressures (8 to 23 bars). Detailed experimental setups and methods for both Butadiene distillation and reactor operation, are given for an industrial polymerization recipe. Simulation studies based on numerical integration of the heat and mass balance equations for cooled reactors show that for the relatively large particle size latex of this study, the reactor is not parametrically sensitive. The influence on the scaleup of the various heat transfer parameters, is discussed.
TL;DR: In this paper, a polyurethane prepared from 1,9-nonanediol and toluene-2,4-diisocyanate with Mn=11,840 was capped on both ends in a reaction with 4-(benzocyclobutenyl) methanol.
Abstract: A polyurethane prepared from 1,9-nonanediol and toluene-2,4-diisocyanate with Mn=11,840, was capped on both ends in a reaction with 4-(benzocyclobutenyl) methanol. The polyurethane was used to crosslink styrene-butadiene rubber through Diels-Alder reactions on the benzocyclobutene functionality. The synthesis and characterization of 4-(benzocyclobutenyl) methanol, a molecule not reported previously, is presented. The crosslinking reaction was carried out on intimate mixtures of the telechelic polyurethane and SBR at elevated temperature and pressure. Various physical properties of the crosslinked material were studied.
TL;DR: In this article, the properties of latex interpenetrating polymer networks (IPNs) were characterized by mechanical, thermal and morphological properties using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).
Abstract: Latex interpenetrating polymer networks (IPNs) were synthe sized from styrene-butadiene rubber (SBR) and styrene, or its co-polymers which were cross-linked with divinyl benzene (DVB). These IPNs were characterized by mechanical, thermal and morphological properties. The ther mal properties were analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The morphology of the IPNs were studied by scanning electron microscopy (SEM). It was found that all semi-IPNs have better mechanical and morphological properties than the corresponding blends.
TL;DR: A new product named Ismacorr 141 has been prepared from raw linseed oil and aniline, which is mainly used as a corrosion inhibitor for overhead distillation towers as discussed by the authors.
Patent•
08 Jul 1992
TL;DR: In this paper, a multi-layer, sealable polypropylene film consisting of a top layer A of a heat-resistant polymer having a melting point above 200 DEG C, an adhesion promoter B consisting of, based on B, 30 to 95% by weight of a styrene butadiene block copolymer.
Abstract: Multi-layer, sealable plastics film consisting essentially of … … A: a top layer A of a heat-resistant polymer having a melting point above 200 DEG C, … B: an adhesion promoter B consisting of, based on B, 30 to 95 % by weight of a styrene butadiene block copolymer, up to 95 % by weight of polystyrene and/or high impact polystyrene and 5 to 70 % by weight of a polymer which is incompatible with polystyrene and contains polar groups, … C: a backing layer C of 5 to 100 % by weight of a styrene butadiene block copolymer and up to 95 % by weight of polystyrene and/or high impact polystyrene, … D: if required a barrier layer D, which can correspond to the cover layer A, … E: a sealing layer E with a composition corresponding substantially to that of the adhesion promoter B. …
Patent•
07 Feb 1992
TL;DR: In this article, the straight grain pattern of styrene butadiene copolymer resins (SBBs) is obtained by laminating the film of SBBs on the material in the same mold, and then the color change due to the thickness difference of the resins occurs, thereby obtaining the straight-grain pattern of shading.
Abstract: PURPOSE:To form the skin with unevenness and shading by laminating the film of styrene butadiene copolymer resin (SBB) which has the straight grain pattern with unevenness and shading at least on one surface of extruded formed styrene resin-sheet as the skin. CONSTITUTION:The SBB which becomes a skin is generally colored with colorant and is melted in a first extruding machine and then is introduced into a mold. When the styrene resin extruded from a second extruding machine is laminated on the material in the same mold, first recessed grooves are provided on the wall-surface of front half of the mold to which SBB flows, and second recessed groves are provided on the wall-surface of rear half of the mold. The second recessed grooves have less depth and width of the groove than those of the first recessed grooves. The SBB resin which passes the first and the second recessed grooves and the SBB resin passes only the second recessed grooves except the first recessed grooves, are generated, and then the color-change due to the thickness-difference of the resin occurs, thereby obtaining the straight grain pattern of shading. When other styrene resins e.g. polystyrene and high impact styrene film are laminated on the rear surface of the sheet, the formed styrene resin-sheet of three layer-laminate is obtained by using a third extruding machine.
01 Jan 1992