Showing papers on "Styrene-butadiene published in 1979"

Multi-layer laminate comprising a modified styrene-butadiene block copolymer

Abstract: A multi-layer laminate comprising at least one A-B double layer structure, characterized in that said layer A is a layer comprising at least one material selected from the group consisting of olefin polymers, polyamide polymers, acrylate polymers, polyether polymers, polycarbonate polymers, polyurethane polymers, vinylidene chloride polymers, thermosetting resins, vulcanized rubbers, glass and papers and said layer B is a layer comprising mainly a modified block copolymer in which an unsaturated carboxylic acid or its derivative is grafted on a styrene-butadiene block copolymer. Said laminate is excellent in interlaminar adhesion, i.e. peeling strength.

Epoxidation of styrene–butadiene block polymers. II

Abstract: Epoxidation of styrene–butadiene block polymers considerably improves their resistance to hydrocarbon oils. Use of peroxyformic acid generated in situ appears to be simple and practical. Although no problems exist when the reactions are carried out in toluene, polymer molecular weight and reactant stoichiometry are important in determining the properties of polymers epoxidized in cyclohexane. In fact, epoxidations in cyclohexane of linear and tapered block polymers of molecular weights in excess of 60,000 with peroxyformic acid invariably lead to gelation. Replacing half or more of formic acid with acetic acid, however, alleviates the problem without adversely affecting the tensile or oil resistance of the resulting polymers. This recipe has also been successfully applied to the epoxidation of divinylbenzene-coupled styrene–butadiene radial block polymers.

Paper coating composition of unsaturated acid and mono-olefin polymerized in the presence of a preformed styrene/butadiene latex

Abstract: Paper coating compositions having an improved combination of properties are prepared by admixing, in the normal proportions and by conventional techniques, one or more conventional paper coating pigments with a particular type of synthetic polymer latex. In such compositions, the particular latex employed is alkali-sensitive and is prepared by emulsion polymerizing (A) from about 10 to about 90 parts by weight of a monomer mixture comprising, based upon the weight of such monomer mixture, (1) from about 10 to about 60 weight percent of an ethylenically unsaturated carboxylic acid monomer and (2) from about 40 to about 90 weight percent of a copolymerizable monoolefin compound in the presence of (B) from about 10 to about 90 parts by weight, on a polymer solids basis, of a copolymer latex comprising a monovinylidene aromatic monomer such as styrene and an open-chain aliphatic conjugated diene such as butadiene.

Composite hard and flexible seal profiles for vehicle windows - involving styrene! butadiene! copolymers co-extruded with EPDM rubber

Abstract: Profiles for guiding and/or sealing the edges of a moving panel of glass, esp. for a vehicle window, are made partly from a hard (65 Shore D) semi-rigid material (I) and partly from a flexible material (II) co-extruded beside or bonded to the rigid parts of profile to provide integral elastic lips or bridges. Specifically claims profiles where (I) is a copolymer predominantly of styrene butadiene but contg. a minor proportion of another compatible monomer, so that (I) can be processed at 140-160 deg. C. Pref. (II) is a conventional ethylene- propylene-diene (EPDM) based rubber. The composite profiles can act simultaneously as guides and seals and also to attenuate vibration and noise. Simpler than metal profiles sheathed with rubber and/or partly lined with felt strips, can tolerate conventional vehicle production painting temps.

Carpet backing adhesive

Abstract: The coagulation of a styrene butadiene latex emulsion which normally occurs upon the introduction of gypsum as a filler in the preparation of an adhesive composition is prevented by the addition of ammonium sulfate or sodium sulfate or a mixture of the two to the emulsion prior to the addition of the gypsum.

Physical Aging Studies of Styrene-Butadiene and Carbonate-Siloxane Block Copolymers

Abstract: : The physical aging process in styrene-butadiene and carbonate- siloxane block copolymers has been studied by monitoring the time dependent changes in mechanical and thermal properties Specifically, stress-strain, stress relaxation and differential scanning calorimetry experiments were utilized For the styrene-butadiene systems, it was found that the rate of physical aging increases with decreasing glassy content between 50 and 100% glass However, the rate must decrease to zero when the percent glass reaches zero The occurrence of physical aging was also noted in the polycarbonate siloxane block copolymer investigated The data are discussed in light of the practical ramification of utilizing these block copolymers in material applications

Cationic latex interaction with pulp fibers. II. Modification of sheet properties by styrene butadiene latex with quaternized amino groups

Abstract: Unbeaten kraft fibers covered with experimental cationic latexes were formed into sheets in which direct fiber-fiber bonds are replaced by polymeric bonds. The effect on sheet properties—breaking length, elongation at break, folding endurance, opacity, and light scattering—was evaluated as a function of latex composition. The composition was altered by either the ratios of styrene to butadiene in the polymer or by mixing soft film-forming and hard nonfilming latex. It is shown that, regardless of latex composition and mechanical properties of the polymeric film, all the latexes can modify the sheet properties to a similar extent, providing that the sheets are heated above the polymer's glass transition temperature. An improvement of tensile strength is accompanied by increased elongation. As a probable mechanism of reinforcement, it is suggested that the polymer acts as a filler of the fiber's surface irregularities, thus providing a larger contact area between fibers and an improved stress transfer between them.

Cationic latex interaction with pulp fibers. I. Deposition of styrene-butadiene latex having quaternized amino groups

Abstract: Four experimental latexes of different styrene-butadiene ratios stabilized with quaternized amino groups were employed in deposition studies on unbeaten kraft pulp fibers. The attraction between the oppositely charged latex and fibers facilitates a ready latex deposition in the pH region between the points of zero charge of the latex and of the fibers. The rate of deposition appears to be controlled by latex diffusion and convection up to the fiber surface. The distribution of latex particles deposited on the fiber surface is related to the butadiene content and the latex stability. Polystyrene latex is the most stable and covers the fibers uniformly as individual particles. With increased butadiene content, the coagulation region of the latex is more extended and the tendency to deposit as aggregates is promoted.

Treatment of styrene-butadiene rubber

Abstract: The adhesion and tack properties of styrene-butadiene rubber (SBR) are improved by replacing from 1% to 25% of the rubber with saponified tall oil pitch, based on the dry weight of the SBR. The SBR may be carboxylated or uncarboxylated, filled or unfilled.

Blends of poly(p-methylstyrene) with polyolefins

Abstract: There is provided a blend of poly (p-methyl-styrene with small amounts of poly (C 2 -C 4 ) olefin, olefin copolymer or styrene butadiene rubber. The blend can be formed into shaped articles, such as food containers, which can be crosslinked by irradiation at low doses. Such articles are resistantto microwave oven conditions.

Polymer sizing compositions and methods yielding sized glass fibers having reduced tackiness

Abstract: Sized glass fibers are rendered less tacky by treating glass fibers with a sizing composition having a blend of components. The sizing composition has about 0.5 to about 2 weight percent of liquid hydroxylated styrene butadiene copolymer, about 0.35 to about 2 weight percent of one or more emulsifiers, about 0.5 to about 1.5 weight percent of a wet lubricant, about 0.5 to about 3 weight percent of one or more dry lubricant oils or waxes and about 0.3 to about 2 weight percent of an organo silane coupling agent. All of the weight percents are of the total aqueous sizing composition. The emulsifier or emulsifiers are those having a fatty acid portion with carbon to carbon chain lengths of at least 14 to about 20 carbon atoms. The wet lubricant has a nitrogenous group to provide hydrogen bonding with the surface of the glass fibers.

The Vulcanization of Styrene-Butadiene Rubber with 2-Pentadecyl-Benzoquinone Dioxime

Abstract: The authors propose a new active vulcanizing agent 2-pentadecylbenzo-quinone dioxime, derivable from the indigenous raw material, cashewnutshell liquid. This vulcanizing agent, when oxidized by red lead, gives styrene-butadiene vulcanizates of improved tensile strength and elongation at break, compared to vulcanizates cured by p-benzoquinone dioxime, 2-methylbenzo-quinone dioxime or standard sulfur curing systems. The new vulcanizates have much greater resistance to heat aging than the corresponding sulfur vulcanisates.

Long service life alkaline accumulator separators - comprise inorganic particles in a polymer binder, pref., styrene!-butadiene! or acrylic! acid-olefin! copolymer

Abstract: A compsn. for producing alkaline accumulator separators comprises a polymer binder in which are embedded micrometric inorganic particles in amt. of 30-80 wt.% w.r.t. polymer and particles. The polymer is pref. a styrene butadiene or an acrylic acid-olefin copolymer. The particles are pref. TiO2, hydrated Ce oxide, Pb peroxide, Mg titanate, Ca zirconate, Al silicate and/or silica. Partic. suitable for Ni/Zn accumulators used in electrical vehicles. The separators can be easily produced and have relatively long service life even under conditions of high discharge, esp. when associated with other materials.

Extruded profile, esp. joint sealant - based on thermoplastic styrene!-butadiene!-styrene! rubber contg. EVA and carbon black (BE 27.12.78)

Abstract: Profile based on SBR with 60-80 (wt.%) butadiene and 40-20% styrene, contains 30-60 pts. EVA and 30-40 pts. C black per 100 pts. thermoplastic styrene-butadiene-styrene rubber (SBS). The compsn. can also contain 2-30 pts. N-isopropyl-N-phenyl-p-phenylene-diamine (I) and/or 20-40 pts. coumarone resin (II), pref. with a m.pt. of ca. 130 degrees C or 20-40 pts. lignin resin, based on lignin sulphonates, modified lignins and their derivs., and/or 5-35 pts. paraffin oil. No vulcanisation is needed and the profile can be bonded easily. It has good physical properties, e.g. great elasticity with slight compression set, optimum tensile strength and elongation at break, high tear strength and good resistance to heat, cold and ageing.

Type of reactive centres in the styrene-butadiene copolymerization over the n-butyl-lithium-tetramethyl ethylenediamine complex☆

Abstract: The rate constant for styrene polymerization over the system n-BuLi-tetramethyl ethylenediamine (kp=0·0±80·02/mole·sec, benzene, 20°C) has been determined in order to estimate the factors determining the behaviour of the catalytic system in the copolymerization, and in particular, to estimate the criss-cross propagation constants. The found kp was smaller than that for the styrene polymerization in benzene over BuLi (k′p=0·5 1./mole·sec, which indicates a lower reactivity of the polystyryl lithium in its complex with tetramethyl ethylenediamine. The spectroscopic study in combination with that of the relative viscosity of the polystyryl lithium solutions with or without the catalytic amounts of tetramethyl ethylenediamine indicate the existence of the monomeric form of polystyryl lithium complexed with one molecule of tetramethyl ethylenediamine.