Showing papers on "Styrene-butadiene published in 1986"

SAXS study of micelle formation in mixtures of butadiene homopolymer and styrene-butadiene block copolymer. 3. Comparison with theory

Abstract: : The theory of block copolymer micelle formation formulated by Leibler, Orland and Wheeler is compared with the experimental results of Rigby and Roe obtained with mixtures of styrene-butadiene diblock copolymer and butadiene homopolymer. To facilitate the comparison, the theoretical expressions are recast in terms of the molecular volume v and the rms end-to-end distance r, thereby avoiding the use of the concept of the segment size a and the number of segment N per molecule. The calculated radii of the micelles show excellent agreement with the observed values. The theory predicts correctly the trend of change in the critical micelle cores to consist predominantly of styrene blocks, whereas the experimental results indicate that above a certain temperature that micelle cores become increasingly swollen with polybutadiene as the temperature is raised toward the dissolution temperature.

Chemically treated glass fibers

Abstract: Chemically treated glass fiber strands can have a reduced tendency for fiber breakage and fuzz ball production through the present invention. The present invention constitutes glass fiber strands where the glass fibers have a moisture-reduced, non-homogenous residue having a lubricious phase, where the residue results from an aqueous chemical treating composition having: a lubricating system; an aqueous soluble, dispersible or emulsifiable film forming polymer that produces a non-rigid film; and water. The lubricating system has one or more polyoxyalkylene polyols and/or polyalkylene polyols with an effective high molecular weight in an effective amount of the solids of the aqueous chemical treating composition to form a lubricious phase and a cationic lubricant. The lubricating system can also have polyethylene glycol, wax. internally lubricated organo silane esters and mixtures thereof. The film forming polymer can be a polymer that results in a film less rigid than unplasticized polyvinyl acetate such as polyvinyl pyrrolidone, carboxylated styrene butadiene copolymer, starch, elastomeric polyurethanes and mixtures thereof. The aqueous chemical treating composition can also have one or more organo silane coupling agents in an effective coupling agent. The chemically treated glass fiber strands are most suitable for twisting while achieving a reduced tendency for filament breakage.

Small-angle x-ray scattering study of micelle formation in mixtures of butadiene homopolymer and styrene-butadiene block copolymer. 2. Effects of block lengths

Abstract: : The small-angle X-ray scattering technique is utilized to determine the characteristics of micelles formed in the mixtures containing a low molecular weight polybutadiene and a styrene-butadiene diblock copolymer. Three different block copolymers of about the same overall molecular weight but with differing lengths of the two blocks are utilized. The observed scattering curve is fitted with a calculated one based on a model of polydisperse micelles interacting with each other according to the Percus-Yevick hard-sphere fluid approximation. The following quantities characterizing the structure of the micelle are evaluated as a function of temperature and copolymer concentration: the average radius of the core, the polydispersity of the core radius, the apparent hard-sphere radius of interaction, the critical micelle concentration, the degree of swelling of the core, and the number density of the micelles. The critical micelle concentration decreases as the proportion of styrene in the copolymer increases. The size of the micelles of a given copolymer remains independent of concentration but shows a moderate variation with temperature, especially immediately before the final dissolution temperature.

Moldable latex impregnated textile material

Abstract: A moldable textile material and process for making a textile material partially or wholly impregnated with a variably stiffening polymer rigidifier comprising: a needled non-woven fabric substrate comprising one or more fibers selected from the group consisting of polyesters, polyacrylics, polyester, copolymers, polyacrylic copolymers, wool, cotton, consensation polymers of diamines and dicarboxylic acids, caprolactam based polymers and regenerated cellulose based polymers; and a latex impregnant comprising at least about 25 percent by weight of water, one or more fillers selected from the group consisting of calcium carbonate, clay and zinc oxide, and one or more stiffeners selected from the group consisting of polystyrene, styrene-acrylonitrile, styrene-acrylonitrile-butadiene, styrene acrylates, styrene butadiene, polyvinyl chloride, polyvinyl acetate, alkyl acrylates, polyvinylidene chloride, ethylene vinyl chloride and copolymer and terpolymer of these resins; the fabric substrate being needled in sheet form to a thickness of between about 75 and about 450 mils, the latex being applied to one or both surface(s) of the substrate and penetrating from about 10% to 100% of the thickness thereof

Crazing in thin films of styrene–butadiene–styrene block copolymers

Abstract: Mecanisme d'amorcage et croissance des fissures et sa relation avec les proprietes mecaniques de films minces de SBS

Bonding Systems for Concrete Repair — An Assessment of Commonly Used Materials

Abstract: Commercially available aqueous polymer dispersions of various types are compared with respect to their bonding properties when used to adhere repair mortars to cementitious substrates. Polymer dispersions tested include a number of acrylates and styrene-acrylates, a styrene butadiene, a vinyl acetate, an acrylate versatate and a vinyl acetate acrylate versatate. A composite bonding aid, an epoxy bonding system and the use of cement and polymer/cement slurries are also examined. Three different test methods are used to measure bond and a simple comparative test has been developed to monitor ‘grab’. The merits of these tests are discussed. The best all round performance including tolerance to site use has been found to be given by an acrylate dispersion.

Effect of Processing Conditions on Styrene-Butadiene-Styrene-Thermoplastic Rubber

Abstract: The effects of shear rate, extrusion temperature and heat treatment on a lamellar triblock copolymer of styrene-butadiene-styrene were studied using extrudates from a capillary rheometer. The rheological behaviour is mainly non-Newtonian in the region studied and the flow curves can be time-temperature reduced. The quality of the domain structure PS phase was measured mechanically in terms of the stress at yield and optically by birefringence. Some of the factors considered during the analysis of the results are: rearrangement of the imperfect original domain structure taking place in the barrel, before extrusion, for temperatures higher than 145°C; partial destruction of this pre-developed structure during extrusion; orientation of the chains during extrusion and under some conditions, the development of sharkskin on the surface of the extrudate. The heat treatment induces the copolymer to undergo three processes: internal stress relaxation (∼135°C); rearrangement of the imperfect domain structure (145°CT240°C); and crosslinking in the rubbery phase (T200°C).

Microstructural influences on volumetric properties of styrene‐butadiene‐styrene block copolymers

Abstract: A water-displacement method was used to measure the specific volume of three styrene-butadiene-styrene (SBS) block copolymers over the temperature range 4°C to 65°C. The polymers contained 0.268. 0.293, and 0.482 weight fraction polystyrene, varied in molecular weight, and are known to be phase-separated at these temperatures. Coefficients of thermal expansion were also obtained and found to be constant over this temperature range. Results are compared with various models of composite behavior, the most successful of which is the linear mixing rule which gives good predictions over this composition range. Deviations for specific volume are negative, and for expansion coefficient positive, from the linear rules. More complex behavior is suggested, however, and this is interpreted in terms of microstructural characteristics. Some apparent contradictions in data reported by other workers are explained. Results are presented also for samples stretched uniaxially up to 300 percent strain; only slight evidence of dilation is seen at 22°C. but increase of the expansion coefficient is more apparent.

Branched random styrene-butadiene copolymer

Abstract: PURPOSE:The titled copolymer, containing styrene units having specific styrene chain distribution in the copolymer chain, having a long-chain branched structure modified with a specific urea derivative and particularly useful as tire treads for low fuel consumption. CONSTITUTION:Styrene is copolymerized with butadiene in the presence of an organolithium compound, e.g. n-propyl lithium, as a polymerization initiator in a hydrocarbon solvent and a urea derivative expressed by the formula (R1 and R2 are 1-4C alkyl or alkoxyalkyl; Y is O or S; n is an integer 2-4), e.g. 1,3-diethyl-2-imidazolidinone, is added to give an Li-terminated modified copolymer, which is then reacted with a polyfunctional coupling agent having >=3 reactive sites to afford the aimed copolymer having 30-150 Mooney viscosity (ML1+4, 100 deg.C), 5-45wt% combined styrene content, >=40wt% styrene single chain having one styrene unit in the combined styrene and =8 styrene units. EFFECT:With improved impact resilience and well-balanced wet skid resistance and abrasion resistance and processability.

Novel random styrene-butadiene copolymer

Abstract: PURPOSE:To produce the titled copolymer containing styrene unit in the copolymer chain forming a specific chain distribution, and useful for tire, etc., by reacting a copolymer having Li bonded to the terminal of the copolymer chain with a urea derivative. CONSTITUTION:The novel copolymer having a Mooney viscosity of 30-150 (ML1+4, 100 deg.C), bonded styrene content of 5-45(wt)%, short styrene chain content consisting of single styrene unit of >=40% of the bonded styrene, and long styrene chain content consisting of >=8 styrene units of <=5%, can be produced by copolymerizing styrene and butadiene using an organic Li compound (e.g. n-propyllithium) as a polymerization initiator, and reacting the resultant Li- terminated copolymer with a urea derivative of formula (R1 and R2 are 1-4C alkyl or alkoxyalkyl; Y is O or S; n is 2-4). EFFECT:The balance of impact resilience, wet-skid resistance and abrasion resistance can be remarkably improved.

Styrene/butadiene copolymer rubber of excellent flex resistance and its production

Abstract: PURPOSE:The titled copolymer rubber excellent in processability, cold flow, flex resistance, tensile strength, resiliency and heat build-up, prepared by coupling a specified random styrene/butadiene copolymer with a silicone coupling agent CONSTITUTION:A random styrene/butadiene copolymer Mooney viscosity (ML1+4-I) of 20-60, obtained by copolymerizing styrene with butadiene in the presence of an organolithium catalyst in a hydrocarbon solvent is coupled with an at lest trifunctional silicon coupling agent (eg, SiCl4) to obtain the titled copolymer having a combined styrene content of 15-35wt%, a Mooney viscosity (ML1+4-C) after coupling of 80-140, an (ML1+4-C)/(ML1+4-I) ratio of 2-4, such a monomodal MW distribution that the MW distribution (Mw/Mn) which is a ratio of the weight-average MW (Mw) by GCP to the number-average MW (Mn) by GPC of 22-4, a free styrene content in an O3 decomposition product >=40wt% based on the total combined styrene content (as analyzed by GCP) and a long-chain block styrene content in the decomposition product <=5wt% based on the total combined styrene content

Crude source effects on the chemical, morphological, and viscoelastic properties of styrene/butadiene latex modified asphalt cements

Abstract: The increasing costs and decreasing availability of good-quality asphalt cements across the United States has warranted the use of modifiers. Provided in this paper is a preliminary fundamental analysis of chemical variables (elemental analysis, molecular weight, functional group analysis, and chromatographic fractionation), microstructural effects as measured by scanning electron microscopy, and viscoelastic changes imparted by styrene/butadiene latex addition as measured by dynamic, mechanical spectrometry. AC-10 and AC-20 asphalt cements from five crude sources representing a wide range of chemical and physical properties were chosen for this study.

Polyblends of Polyethylenes and Polypropylene with Styrene/Butadiene/Styrene Thermoplastic Elastomer:

Abstract: are not completely compatible, but separate into separate phases which remain strongly bonded together at the interfaces. Styrene/butadiene/sytrene (SBS) sandwich block copolymer thermoplastic elastomers have sometimes been recommended for polyblending with polyethylenes and polypropylene [3,4]. Since these are crystalline polymers, very low in polarity, and offer no possibility of hydrogen bonding, it would not be expected that they would form a compatible single homogeneous phase. In forming separate phases, however, they might be similar enough in polarity to form strong interfaces, and thus offer the possibility of synergistic improvement in balance of properties.

Styrene/butadiene random copolymer composition

Abstract: PURPOSE:To provide rubber for tire, which has well-balanced properties between resilience and wet skid resistance, consisting of a straight-chain component and a branched component so as to allow the styrene units in the copolymer chain to be formed by a specified styrene chain distribution CONSTITUTION:A styrene/butadiene random copolymer is composed of 25-75wt% straight-chain component (A) and 75-25wt% branched component Component A is a reaction product of a lithium-terminated copolymer (a) with a urea derivative of the formula, obtd by copolymerizing styrene and butadiene in the presence of an organolithium compd in a hydrocarbon solvent Component B is a reaction product of said copolymer (a) with a polyfunctional coupling agent contg at least three reactive moieties The random copolymer has a Mooney viscosity (ML1+4, 100 degC) of 30-150 and a bonded styrene content of 5-45wt% wherein the styrene unit composed of a single styrene chain is at least 40wt% of the bonded styrene and styrene unit composed of a long chain of at least 8 styrene units is not more than 5wt% of the bonded styrene

Photographic processing composition with poly(diacetone acrylamide) oxime and styrene-butadiene latex

Abstract: Photographic processing compositions containing a light-reflecting pigment and a styrene-butadiene copolymer are disclosed. The photographic processing compositions are useful in photographic diffusion transfer film units and processes for the provision of permanent photographic laminates. A light-reflecting layer formed in a photographic laminate from such a processing composition exhibits a reduced tendency toward cohesion or adhesion failure and separation.

Electrically-conductive coating compound

Abstract: PURPOSE:The titled inexpensive coating compound having imrpoved flexibility and low density, obtained by blending essential components comprising a polymer such as styrene butadiene styrene block copolymer, etc., a resin composition for reinforcing bonding, carbon fiber, carbon black, etc. in a specific ratio with a crosslinking agent, etc. CONSTITUTION:(A) 100pts.wt. one or more polymers selected from a group consisting of styrene butadiene block copolymer, styrene ethylene butyelne styrene block copolymer, chloroprene rubber, acrylonitrile butadiene rubber and its reprocessed rubber is blended with (B) 30-600pts.wt. resin composition (e.g., phenolic resin) for reinforcing bonding, (C) 20-450pts.wt. carbon fiber, (D) 1-60pts.wt. carbon black, and (E) 5-70pts.wt. chlorinated rubber to give a polymer compound, which is blended with (F) a necessary amount of a crosslinking agent, a plasticizer, a filler, an anti-foaming agent, a coupling agent, a solvent, etc., to give the aimed coating compound.

Reinforced rubber compositions, process for preparing them and their use

Abstract: Reinforced rubber mixture of A) at least one natural, styrene butadiene, polybutadiene, polyisoprene, Transpolyoctenylen-, ethylene-propylene-diene terpolymer and butyl rubber, B) at least one phenol novolak resin and / or reactive polyphenol, C) curing agents and, if appropriate, D) customary additives, the rubber mixture contains as an additional component e) on at least one polar, chlorine-free rubber in the form of nitrile rubber having at least 32% of nitrile or polyurethane rubber in a proportion by weight of 1 to 49 wt .-%, based on the total amount contains rubber. A process for their preparation and use of the reinforced rubber mixtures for the manufacture of technical rubber products, in particular for producing damping elements, rubber sleeves, coatings, conveyor belts and tires.

Rubber composition of improved cutting and chipping resistance

Abstract: PURPOSE:To obtain the titled composition suitable for tire tread use, by incorporating a base rubber with specified amount of petroleum resin of specific structure prepared from copolymerization of cyclopentadiene and/or dicyclopentadiene in specific proportion. CONSTITUTION:The objective composition can be obtained by incorporating 100pts. by wt. of at least one sort of rubber selected from natural rubber and diene-based synthetic rubbers (e.g., styrene butadiene rubber) with (A) 1-30(pref. 3-15)pts. by wt. of a petroleum resin prepared by copolymerization between A1: >=30wt% of cyclopentadiene and/or dicyclopentadiene and A2: <=70wt% of C5- and/or C9- fraction, by-product(s) from naphtha cracking other than the component A1 with a ratio of the double bond in the norbornene ring (ND) to that in the cyclopentene ring (CD):ND/CD falling between 0.2 and 0.9 (pref. between 0.3 and 0.7).

Resin composition for coating compound

Abstract: PURPOSE: To obtain the titled composition suitable for coating metals and plastics, having improved weather resistance, by polymerizing a specific acrylic vinyl monomer in an inert solvent having dissolved a hydrogenated styrene butadiene styrene block copolymer. CONSTITUTION: (B) A vinyl monomer (one containing 0.5W20wt.% hydroxyl group-containing vinyl monomer such as preferably hydroxyethyl methacrylate) containing ≥50wt.% (meth)acrylic ester containing 1W8C alkyl or cyclohexyl group is polymerized in (A) (ii) an inert solvent consisting of toluene or xylene having dissolved (i) a hydrogenated styrene butadiene styrene block copolymer to give the aimed composition. The ratio of the component i/B is 2/8W7/3 (weight ratio). COPYRIGHT: (C)1988,JPO&Japio

Dielectric properties of styrene―butadiene rubber/silica mixtures

Abstract: Rice husk ash (RHA) obtained from rice mill and hydrated silica from RHA were used as a filler in vulcanized SBR 1502 and the dielectric properties were measured at a frequency of 1592 Hz at room temperature. The optimum hydrated silica content giving a good dielectric constant and conductivity was 125 parts/100 parts rubber and the dielectric loss was also high so that it could be a good insulater. There was no significant change in dielectric constant, dielectric loss and conductivity of SBR 1502 filled with RHA which could be used as high frequency dielectric due to low dielectric loss.

Corrosive agent of emulsion baking type

Abstract: PURPOSE:The titled corrosive agent useful for reinforcing rods in concrete, having improved workability, durability of film of coating, shelf stability, etc., obtained by blending aqueous emulsion of a film-forming high polymer with a hot-melt organic filler having a specific melting point or softening point. CONSTITUTION:(A) Aqueous emulsion of film-forming high polymer (preferably the high polymer is carboxylated styrene butadiene rubber having preferably <=20 deg.C lowest film-forming temperature) is blended with (B) a hot-melt organic filler (preferably uncured epoxy resin, etc., granules having 40-200mum particle diameter or short fibers having 0.1-10mm length) having 40-250 deg.C melting point or softening point, a temperature at least 10 deg.C (preferably at least 50 deg.C) higher than the film-forming temperature of the component A, and, if necessary, (C) a bituminous emulsifying agent (e.g., asphalt emulsifying agent), etc., in a weight ratio of the component (solid content):B:C of 100:20-7-30, to give the aimed composition.

Properties of synthetic polymer modified bitumen concentrates and the effects of dilution by bitumen for application as binders

Abstract: Increased elastic properties of bitumen for use as binders are obtained by blending with a styrene butadiene styrene (sbs) linear block copolymer above its glass temperature to produce a concentrate, which is diluted with various quantities of bitumen for use on pavements as a binder. Bitumen stabilisers and additives are used for reducing oxidation, thermal degradation, photochemical breakdown caused by uv light and adjusting aromaticity to obtain compatible blends. Physical properties were determined for the concentrate and blends prepared by dilution of the concentrate with various bitumens from different suppliers. The variability caused by using bitumen of the same classification from alternative suppliers was identified. Thermal degradation of the concentrate and blends were investigated in the temperature range of 110 to 190 degrees celsius, which provides guidelines for handling these materials before their use as binders. Subjective comments are made on their performance over periods of up to five years under climatic conditions of New South Wales and the Northern Territory. Results so far are encouraging (a).

Production of styrene/butadiene copolymer rubber of excellent flex resistance

Abstract: PURPOSE:To obtain the titled rubber excellent in flex resistance, tensile strength, resilience, etc., by coupling a specified random styrene/butadiene copolymer obtained by copolymerization in the presence of a vinylating agent and an allene compound with a coupling agent. CONSTITUTION:Styrene is copolymerized with butadiene in 1-20pts.wt., per pt.wt. monomer, hydrocarbon solvent in the presence of 0.3-3mmol, per 100g of monomer, of an organolithium catalyst, 0.01-50mol, per mol of catalyst, of a vinylating agent (e.g., ethylene glycol dialkyl ether) and an allene compound of formula III (wherein R is H or a 1-10C alkyl) in an amount satisfying relationships I and II [wherein S is a combined styrene content (wt%), V is a vinyl bond content (%) of the butadiene portion, and A/L is an allene compound/catalyst molar ratio] to obtain a random styrene/butadiene copolymer of a Mooney viscosity ML1+4-I of 20-60. This copolymer is coupled with an at least trifunctional silicon coupling agent to obtain the titled rubber of a content of said S component of 15-35wt%, a V component content of 20-40wt% and a Mooney viscosity ML1+4-C after coupling of 80-140 and an ML1+4-C to ML1+4-I ratio of 2-4.

Measurement and Correlation of Solubilities of Hydrocarbon Gases in Styrene-Butadiene Copolymers

Abstract: スチレン-ブタジエン共重合体に対する12種の炭化水素気体 (i-ブタン, n-ブタン, 2, 2-ジメチルブタン, n-ヘキサン, n-オクタン, n-デカン, シクロヘキサン, 1, 3-ブタジエン, ベンゼン, トルエン, エチルベンゼン, メシチレン) の質量分率基準ヘンリー定数を, ガスクロマトグラフ法を用いて温度範囲150～225℃, 大気圧下で決定した.なお, 共重合体には, スチレン含有量30, 45, 77%の3種を用いた.さらに, Perturbed-Hard-Chain理論により質量分率基準ヘンリー定数を相関したところ, ほぼ良好な結果が得られた.なお, 相関に必要な溶質と共重合体の相互作用パラメータは, 溶質とホモポリマーの相互作用パラメータを用いて, 温度のみの関数で表現することができた.