Showing papers by "Rhône-Poulenc published in 1977"

Uni- and biaxial orientation of polymer films and sheets

Abstract: Uni- and biaxial stretching of various polymer films has been studied under well-defined conditions of temperature and elongational strain rate in order to determine the relationship between stress and recoverable strain for both modes of deformation. The extent of molecular orientation has been investigated with the aid of stress optical methods: In amorphous polymers birefringence was found to be directly proportional to the frozen-in internal entropic stress irrespective of the latter's relationship with recoverable strain. In a first approximation, molecular orientation can be understood in terms of deformation of a rubberlike network with temporary junction points. The total internal stress in an oriented glassy polymer may be significantly larger than the entropic stress. Experimental methods based on retractive force measurements, able to distinguish between internal stresses of different nature, are described. In uni- and biaxially drawn films of polyethylene terephtalate preferred planar orientation of (100) planes has been studied by means of X-ray diffraction and measurement of the three principal refractive indices. The intrinsic birefringence of completely oriented PET films has been estimated from these measurements with the aid of the Lorentz-Lorenz theory. The effect of draw ratio and temperature on the rate of crystallization and its consequences (increase of stretching stress and density, decrease of shrinkage) has also been studied. Finally, the effect of molecular orientation on various mechanical properties: modulus, tensile strength, impact resistance, creep compliance, is discussed for both amorphous and semicrystalline polymers, with special emphasis on the predominant influence of amorphous phase orientation.

Hydrophilic polyurethanes and their application as soil-release, anti-soil redeposition, and anti-static agents for textile substrates

Abstract: Novel linear hydrophilic polyurethane polymers are presented. The polymers provide outstanding soil-release, anti-soil redeposition and anti-static properties when applied to natural and synthetic textile substrates, especially textile substrates containing polyester fibers. These polyurethanes are particularly useful in detergent compositions.

Structure of nosiheptide, a polythiazole-containing antibiotic

Abstract: NOSIHEPTIDE is a metabolite with a strong antibiotic action which has been isolated from Streptomyces actuosus (F. Benazet et al., unpublished). Studies of its antibiotic spectrum and cross-resistance suggested that it belonged to the thiostrepton family1; chemical analyses and further chemical degradation confirmed this view. From analytical and spectroscopic data (NMR 1H, 13C and 15N) the general formula C51H43N13O12S6 was assigned (A. Brun, H. Depaire, G. Lukacs and J. P. Thomas, unpublished). Unfortunately no M+ peak can be extracted from its mass spectrum (electron impact). Some parts of the molecule have been identified after degradation by different techniques, namely one L-threonine, one hydroxypyridine, five thiazoles and one indole ring (A. Brun, H. Depaire, G. Lukacs, and J. P. Thomas, unpublished). Nothing could be deduced about the sixth sulphur atom. At least twenty antibiotics are known to contain thiazole rings (for instance bleomycins2, bacitracin A2, and althiomycin3), but among those containing five thiazole rings only two molecular structures are known: thiostrepton, by X-ray analysis4 and 13C NMR spectroscopy, and siomycin A, by comparing its NMR spectrum with that of thiostrepton5. To obtain the complete structure of nosiheptide, we undertook an X-ray analysis.

Rapidly curable, storage-stable organosilicon compositions

Abstract: An organosilicon composition is disclosed which is storage-stable in the absence of moisture and is rapidly curable into elastomers with self-adherent properties in the presence of water at room temperature. Such compositions are prepared by mixing: (a) at least one α,ω-di(hydroxy) diorganopolysiloxane polymer, (b) at least one organosilicon resin, (c) at least one alkoxylated organosilicon compound, and (d) at least one organic titanium derivative.

Action of the palmitic ester of pipotiazine on dopamine metabolism in the nigro-striatal, meso-limbic and meso-cortical systems

Abstract: The effects of a single injection of the palmitic ester of pipotiazine on dopamine synthesis were examined in slices of the striatum, the olfactory tubercule + nucleus accumbens and the frontal and anterior cingulate parts of the cerebral cortex in the rat. In the two first structures, dopamine synthesis was determined by measuring the rate of formation of 3H−H2O during the conversion of l-3,5-3H-tyrosine into 3H-Dopa. Newly synthesized 3H-dopamine and 3H-noradrenaline were measured in the cerebral cortex. In some experiments, the specific activity of tyrosine in the tissues was determined in order to calculate the conversion index of tyrosine into dopamine.

Process for the preparation of water-soluble acrylic polymers by photopolymerization

Abstract: Water-soluble acrylic polymers are prepared by a sequential photopolymerization process. A monomer solution is deposited on a support which is subsequently irradiated to effect polymerization. Photopolymerization promoters are incorporated in the monomer solution to facilitate polymerization.

Telomerization process using sulfonated triarylphosphine and transition metal

Abstract: A process for the telomerization of dienes with a telomerizing compound containing a mobile hydrogen atom is disclosed wherein the reaction between the diene and the telomerizing agent is effected in the presence of a catalytic system comprising a water-soluble sulfonated triaryl phosphine compound, preferably a water-soluble salt of a mono-, di-, or trisulfonated triphenyl phosphine and a transition metal compound, preferably palladium or a palladium-containing compound. Water is added either before or after the reaction is completed and the reaction products can easily be separated from the aqueous catalyst solution.

Novel catalyst for oxidizing olefins in α,β-unsaturated aldehydes and preparation thereof

Abstract: A novel catalyst composition is disclosed which comprises a catalytically-active metal oxide component containing the oxides of cobalt, molybdenum, bismuth, and iron corresponding to the empirical formula: Co.sub.a Mo.sub.12 Fe.sub.b Bi.sub.c O.sub.x wherein: A is a value of between about 8 and about 10, B is a value of between about 0.5 and about 2, C is a value of between about 0.5 and about 2, And x equals the sum of 1.5c+1.5b+a+36 and including a crystalline phase having the empirical formula Bi 2 Mo 2 Fe 2 O 12 . The catalyst composition is prepared by subjecting a conventionally prepared precursor composition to a two-step calcination, comprising two calcining procedures at a temperature of 450°-500° C. and an intermediate cooling to ambient temperature. The novel catalysts exhibit a high activity and selectivity in a process for preparing α,β-unsaturated aldehydes by oxidizing olefins.

Characterisation of poly(vinylchloride)

Abstract: - 0.5 10-3 Long branch and 5 10-3 chloromethyl group per monomer unit (m.u.) possibly originating from head-to -head monomer placement are found in industrial PVC (fewer in low-temperature polymerized products). Tertiary chlorine atoms, if any, correspond to long branches; internal double bonds (0.05 10-3 per m.u. and over) can start polydiene sequences. 1H and 13C NMR spectroscopy shows that syndiotactic placement is slightly favored over isotactic, depending only on polymerization temperature (PT). The number of aggregates in solution is very sensitive to PT, increasing with syndiotacticity, and heating up gives molecular solutions. Crystallizability increases with syndiotacticity, and two types of crystals exist; crystallinity is higher in virgin powder, and fusion range covers 120° to 220°. Annealing over 110° develops a lower order detectable by DSC. A zone of higher density disappearing at 210° is seen at the center of virgin PVC “one micron granules”. The temperature of pseudofusion in plasticizers depends on heat treatment, and the kinetics of impregnation reveals morphological heterogeneities.

Process for crystallizing an adduct of 2,2-di(4-hydroxyphenyl) propane and phenol

Abstract: 2,2-di(4-hydroxyphenyl) propane, ie, diphenylolpropane, is purified by preparing a liquid mixture of raw diphenylolpropane, phenol and water and applying reduced pressure thereto corresponding to the vapor pressure of the mixture while simultaneously cooling same whereby an adduct of pure diphenylolpropane and phenol is crystallized

Water-soluble polyurethanes and compositions and application thereof to substrates

Abstract: Water-soluble polyurethanes are obtained by reacting sulfonated anionic polyesters containing about 0.8 to 2% sulfur with at least one diisocyanate to form film-forming polyurethanes which are directly soluble in water. The polyurethanes of the invention are advantageously applied in aqueous solution form as sizing for textiles and for bonding leathers.

Molding process for the fabrication of hollow shaped articles

Abstract: Hollow shaped articles are extruded, advantageously continuously extruded, from molten thermoplastics by controlled cooling of the molten charge prior to entry into an extrusion die.

Treatment of pulp mill effluents

Abstract: Pulp mill effluents, particularly soda-containing treatment liquors, are subjected to a separatory treatment comprising a pre-treatment with flocculating agent in a sub-critical amount incapable of effecting flocculation, followed by an ultrafiltration of the pre-treated effluent.

Adhesive-coating composition for organic or mineral filaments

Abstract: The present invention relates to an adhesive-coating composition for increasing the adhesion of heat-stable, high-modulus, modal, polyester-based yarns and glass fibres towards compounded rubbers based on natural rubber and on synthetic rubber, said composition comprising a solution of a precondensed resorcinol/formaldehyde resin, a latex based on vinylpyridine and polychloroprene latex, 28% strength ammonium hydroxide and a dicarboxylated butadiene/styrene resin. Yarns and fibres coated with the adhesive-coating composition of the invention are useful in the manufacture of tires, conveyors, conveyor belts, hoses and the like.

Process of hydrocyanation of unsaturated organic compounds containing at least one ethylenic double bond

Abstract: A process of hydrocyanation of unsaturated organic compounds, which contain at least one ethylenic double bond, comprising reacting these compounds with hydrogen cyanide in the presence of an aqueous solution of a sulfonated triarylphosphine compound preferably a water soluble salt of a mono- di- or trisulfonated triphenylphosphine which contains a transition metal compound, preferably a nickel compound. When the reaction is completed the resulting hydrocyanated compound and the catalytic solution can easily be separated and the latter be reused.

Fireproof laminations for electric and electronic devices and methods therefor

Abstract: Fireproof laminations for electric or electronic devices are comprised of a cellulosic substrate impregnated with a phenolic resin, further incorporating a fireproofing-effective quantity of encapsulated red phosphorus particulates.

Process for the preparation of hydrogenosilanes

Abstract: A process for preparing hydrogenosilanes by hydrogenating disilanes, especially halogenated disilanes, under relatively mild reaction conditions is disclosed. The hydrogenation is effected in the presence of a catalytic system containing an aprotic compound and a nickel catalyst which consists essentially of finely divided nickel and is obtained by preliminary or in situ reduction of a nickel compound.

Device for soil irrigation

Abstract: An irrigating device formed from an absorbent product, such as a polymeric pulp or hydrophilic textile contained within a filtering envelope, such as a woven, knitted or non-woven fabric. The device is placed in the ground in communication with a source of water which may be above or below ground. The irrigation device provides for a uniform rate of irrigation of the soil in which it is placed, requires less water than conventional irrigation devices providing the same overall coverage, and is not subject to dogging or blockage, as with conventional irrigation devices. In one embodiment for preparing the irrigation device, the absorbent product is in the form of a tow of hydrophilic continuous filament and the textile filter envelope is produced in a continuous in-line operation in conjunction with the production of the tow. The irrigation device can be applied to the irrigation of soils to facilitate the growth of plants, trees, crops and the germination of seeds.

Single-stage process for the preparation of terephthalic acid

Abstract: Highly pure terephthalic acid is prepared from di-potassium terephthalate. The terephthalic acid so produced aids in the direct production of high quality polyester fiber.

Surface-active composition based on non-ionic surfactants

Abstract: SURFACE-ACTIVE COMPOSITION BASED ON NON-IONIC SURFACTANTS Abstract Surface-active composition based on non-ionic surfactants derived from ethoxylated saturated primary fatty alcohols. The composition is characterized in that it contains a solid mixture at ambient temperature of: a) at least one non-ionic surface-active com-pound A of general formula : R-(OCH2CH2)nOH in which Ris a C6 to C9 alkyl group and n is greater than 6 and may be as high as 15, b) at least one non-ionic surface-active com-pound B of general formula : R'-(OCH2CH2)mOH in which R' is a C16 to C20 alkyl group and m is 6 to 15, in which more than half the groups R and R' taken separately are linear. It can be used in detergent formulations, especially pulverulent or liquid syndet compositions for domestic and/or industrial washing and degreasing purposes.

Phthalate mixtures useful as liquid dielectrics

Abstract: Liquid dielectric compositions useful as electrical insulators are comprised of a mixture of a mixed phthalate of isobutyl alcohol and a branched higher alkanol of a diisobutyl phthalate and/or a phthalate of a branched higher alkanol, and wherein the alkyl groups of the constituents contain from 5 to 18 carbon atoms.

Method and apparatus for carrying out a reaction between streams of fluid

Abstract: The invention concerns a method and apparatus for carrying out a reaction, particularly an exothermic one, between fluids, at a certain distance from the walls, the walls being protected from excessive heating. The apparatus comprises an external casing which is cylindrical or frustoconical, an internal perforated wall which is co-axial with the casing and which bounds the reaction chamber, an axial injection pipe for part of the reagents and a tangential feed pipe for another part of the reagents, the feed pipe imparting a symmetrical helical movement to them. The method is specially applied to the combustion of many different fluids, and the apparatus enables the heat liberated to be directed in a very flexible manner.

Polymerization of organopolysiloxanes

Abstract: Organopolysiloxanes are polymerized in the presence of an alkaline catalyst and a complex oxygen, sulfur or nitrogen heterocyclic compound.

Process for preparing foams from polyisocyanates and polyepoxides

Abstract: Polymers comprising polyoxazolidone and carbodiimide recurring units of the formula: ##STR1## are prepared from polyisocyanates and polyepoxides. Non-friable, low density fire resistant foams are prepared directly from the polymers of the invention without the equisite addition of pore-forming agents.

Use of oxo‐metallic derivatives in isomerization. reactions of unsaturated alcohols

Abstract: The isomerisation of α-acetylenic alcohols to ethylenic carbonyl derivatives and the isomerisation of α-ethylenic alcohols to the corresponding allyl alcohols may be effected in good yields in a single step using oxometallic derivatives The vanadate esters are particularly efficient Mechanistic explanations are given