Abstract: A process for synthesizing an azo compound by oxidation of a hydrogen compound in the presence of a catalyst and a compound of formula (I) is described in which R1, R2 and R3 (R1)(R2)C(PO3(R3)2)2??(I) are as defined. The use of a compound of formula (I) as complexing agent for a catalyst is also described.

Abstract: The present invention relates to an improved process for preparing hydrazine hydrate from the azine of methyl ethyl ketone obtained from methyl ethyl ketone by oxidizing ammonia with hydrogen peroxide in the presence of an activator, characterized in that it comprises a step of recycling the methyl ethyl ketone oxime purge.

Abstract: The present invention relates to an improved process for preparing hydrazine hydrate from the azine of methyl ethyl ketone obtained from methyl ethyl ketone by oxidizing ammonia with hydrogen peroxide in the presence of an activator, characterized in that it comprises a step of recycling the pyrazoline-class heterocycles purge.

Abstract: A process for synthesizing an azo compound by oxidation of a hydrogen compound in the presence of a catalyst and a compound of formula (I) is described in which R1, R2 and R3 (R1)(R2)C(PO3(R3)2)2??(I) are as defined. The use of a compound of formula (I) as complexing agent for a catalyst is also described.

Abstract: A process is provided for synthesizing an azo compound, such as AIBN, by oxidation of a hydrazo compound using hydrogen peroxide. This process comprises a step of adding to the reaction medium a particular reducing agent, such as hydrazine.

Abstract: A process is provided for synthesizing an azo compound, such as AIBN, by oxidation of a hydrazo compound using hydrogen peroxide. This process comprises a step of adding to the reaction medium a particular reducing agent, such as hydrazine.

Abstract: The present invention concerns a method for production of foams of thermoplastic polymer such as polyethylene, polypropylene, polystyrene, polyvinyl chloride. More specifically its goal is a method for production of thermoplastic foams comprising a premixing step of at least a thermoplastic polymer in the form of a divided solid with at least an ester of azocarboxylic acid.

Abstract: The invention relates to novolac alkylphenol resins having a low level of free alkylphenol, a method for the production thereof, and the use thereof as tackifying resins and reinforcing resins for rubbers. The resins may be used advantageously in the production of tires.

Abstract: The invention relates to novolac alkylphenol resins having a low level of free alkylphenol, a method for the production thereof, and the use thereof as tackifying resins and reinforcing resins for rubbers. The resins may be used advantageously in the production of tires.

Abstract: The present invention concerns a method of manufacturing a graded index plastic optical fiber having an index that varies continuously between the center and the periphery of the fiber, from at least one polymer P and at least one reactive diluent D1 to allow the refractive index of said fiber to be varied.

Abstract: The present invention concerns a method of manufacturing a graded index plastic optical fiber having an index that varies continuously between the center and the periphery of the fiber, from at least one polymer P and at least one reactive diluent D1 to allow the refractive index of said fiber to be varied.

Abstract: The present invention concerns a method of manufacturing a plastic optical fiber from at least one polymer P, said method being characterized in that said polymer P is a copolymer comprising at least two repeating units P1 and P2 with the following general formulae, i and j corresponding to a repeat number of units: said copolymer P being transparent, amorphous in nature and having a motif P2 content in the range from substantially 30 mole % to 70 mole % when X?F or Cl in P1.

Abstract: The invention comprises a vinylene carbonate (VCA) copolymer having as comonomer chlorotrifluoroethylene (CTFE) or tetrafluoroethylene (TFE). This copolymer is transparent, making possible the preparation of objects acting as guide or conductor for light with wavelengths of visible or near infrared type. Furthermore, it exhibits a glass transition temperature of greater than 60° C. which is appropriate for the preparation of optical fibers.

Abstract: The present invention comprises a transparent and partially fluorinated polymer which comprises three repeat units resulting from industrial monomers which are simple to access and which has a glass transition temperature of greater than 25° C., which polymer makes possible the preparation of articles, in particular of articles acting as guide or conductor for light in the region of the wavelengths of visible or near infrared type. This polymer is of use in the manufacture of optical fiber.

Abstract: The invention relates to a composition including (i) at least one polyamide and at least one copolymer (A) of ethylene with at least one comonomer chosen from unsaturated carboxylic acids, esters of unsaturated carboxylic acids or vinyl esters of saturated carboxylic acids and (ii) being in powder form. These compositions are subsequently deposited on metal substrates and then a highly corrosion-resistant coating is obtained by melting.

Abstract: In order to manufacture pentafluoroethane (F125) and/or 1,1,1,2,3,3,3-haptafluoropropane (F227ea), a trifluoromethane gas stream is subjected to pyrolysis and then the mixture of gases which result from this pyrolysis is brought into contact with a fluorination catalyst.

Abstract: To avoid the formation of acidity in an F125 containing olefins, a radical scavenger and/or an acidity scavenger is added to it.

Abstract: The invention relates to a mixture in powder form and comprising (i) at least one polyamide and (ii) at least one polymer (A) containing hydroxyl functional groups and compatible with the polyamide. The polymer (A) may be an ethylene/vinyl alcohol copolymer. The mixture may be used to coat metal substrates.

Abstract: In order to remove olefinic impurities present in a hydrofluorocarbon such as pentafluoroethane (R-125), the impure hydrofluorocarbon is treated with oxygen in the absence of catalyst or of active charcoal.The process is well suited to the purification of fluoroethanes and, more particularly, to that of pentafluoroethane.

Abstract: Polyetheresteramides, characterized in that they comprise both of the following repeating entities: ##STR1## in which X represents the residue of a polyamide-diacid oligomer with an Mn of between 300 and 8000, Y represents the residue of a polyetherdiol with an Mn of between 200 and 5000, and Z represents the residue of a polyetherdiamine with an Mn of between 200 and 5000, wherein the proportion by mass of the entities Z resulting from the condensation of the polyetherdiamine with respect to the total amount of the entities resulting from the polyetherdiol and polyetherdiamine, i.e. Z/(Z+Y), is between 1 and 50%. The polyetheresteramides according to the invention can be used as is and are suitable for the production of mouldings, extrudates, films, sheaths, or composite materials such as multi-layer film. They can also be mixed with other polymers and in particular with polyamides.