Abstract: The invention relates to scorch prevention and, more specifically, to a composition which comprises a nitroxide and at least one organic peroxide and which can be used to delay scorching prior to crosslinking of thermoplastic compositions and/or elastomers. The invention also relates to a crosslinkable composition and to a crosslinking method.

Abstract: The present invention relates to a process for manufacturing acrolein by gas-phase dehydration of glycerol in the presence of strongly acidic solid catalysts with a Hammett acidity H0 of between ?9 and ?18 and preferably between ?10 and ?16.

Abstract: The present invention relates to a process for manufacturing acrolein by gas-phase dehydration of glycerol in the presence of strongly acidic solid catalysts with a Hammett acidity H0 of between ?9 and ?18 and preferably between ?10 and ?16.

Abstract: The invention relates to scorch prevention and, more specifically, to a composition which comprises a nitroxide and at least one organic peroxide and which can be used to delay scorching prior to crosslinking of thermoplastic compositions and/or elastomers. The invention also relates to a crosslinkable composition and to a crosslinking method.

Abstract: The present invention relates to the prevention of scorching before crosslinking of a thermoplastic and/or elastomeric composition with peroxides or azo compounds. This is achieved by using a family of specific nitroxides as additive.

Abstract: The present invention relates to the prevention of scorching before crosslinking of a thermoplastic and/or elastomeric composition with peroxides or azo compounds. This is achieved by using a nitroxide in combination with at least one crosslinking promoter (promoter) chosen from group (P) consisting of compounds containing at least one double bond, which may be difunctional or polyfunctional.

Abstract: The present invention relates to the prevention of scorching before crosslinking of a thermoplastic and/or elastomeric composition with peroxides or azo compounds. This is achieved by using a family of specific nitroxides as additive.

Abstract: The present invention relates to the prevention of scorching before crosslinking of a thermoplastic and/or elastomeric composition with peroxides or azo compounds. This is achieved by using a nitroxide in combination with at least one crosslinking promoter (promoter) chosen from group (P) consisting of compounds containing at least one double bond, which may be difunctional or polyfunctional.

Abstract: The present invention relates to the prevention of scorching before crosslinking of a thermoplastic and/or elastomeric composition with peroxides or azo compounds. This is achieved by using a family of specific nitroxides as additive.

Abstract: The invention concerns a method of polymerization in aqueous suspension of vinyl chloride alone or mixed with another vinyl monomer, wherein the initiator comprises at least a compound selected from dialkyl peroxydicarbonates, peroxy-tert-alkanoates and diacyl peroxides, and it consists in using, as short-stopper of the polymerization, a stable free nitroxyl radical. The resulting resins have good whiteness.

Abstract: The present invention relates to a process for obtaining isophorone from acetone, characterized in that the operation is carried out (i) in liquid phase in the presence of a magnesium aluminum double oxide of formula Mg.sub.1-x Al.sub.x O.sub.1+x or (ii) either in gaseous or liquid phase in the presence of a catalyst of general formula (I):?(Mg.sup.2+).sub.1-x (Al.sup.3+).sub.x (OH.sup.-).sub.2 !.sup.x+ ?(OH.sup.-).sub.x !.sup.x- (H.sub.2 O).sub.n (I)with 0.20.ltoreq.x.ltoreq.0.33 and n<1.

Abstract: The aldolization is characterized by the use of a solid basic catalyst which has the following general formula?(Mg.sup.2+).sub.1-x (Al.sup.3+).sub.x (OH.sup.-).sub.2 !.sup.+x ?(OH.sup.-).sub.x (H.sub.2 O).sub.n !.sup.-x (II)wherein 0.20.ltoreq.x.ltoreq.0.33 and n has a value of less than 1. This catalyst has a defined crystal structure similar to that of hydrotalcite or, alternatively, of meixnerite. Also disclosed are processes for the preparation of the catalyst.

Abstract: The invention relates to the preparation of n-perfluorooctyl bromide. The continuous process according to the invention consists in reacting bromine with 1-hydroheptadecafluoro-n-octane in the gaseous phase, at a temperature between 450.degree. and 520.degree. C. in a Br.sub.2 /C.sub.8 F.sub.17 H mole ratio which can be from 0.2 to 5 and with a contact time between 2 and 240 seconds.The C.sub.8 F.sub.17 Br selectivity is almost complete and information of toxic sub-products like perfluoroisobutene is avoided.

Abstract: An amphoteric starch containing carboxyl and cationic groups characterized in that its carboxyl groups originate from the selective oxidation of the hemiacetal groups of the cationic starch and possibly of the hemiacetal groups of its products of acid hydrolysis. The process for producing the amphoteric starch consists in reacting a cationic starch in aqueous solution with hydrogen peroxide and hydrobromic acid or bromine, so as to oxidize selectively the hemiacetal groups of the cationic starch and, where appropriate, the hemiacetal groups of its products of acid hydrolysis, to give carboxyl groups.

Abstract: This process consists in reacting a cationic starch in aqueous solution with hydrogen peroxide and hydrobromic acid or bromine, so as to oxidize selectively the hemiacetal groups of the cationic starch and, where appropriate, the hemiacetal groups of its products of acid hydrolysis, to give carboxyl groups. The amphoteric starch containing carboxyl and cationic groups, thus obtained, is characterized in that its carboxyl groups originate from the selective oxidation of the hemiacetal groups of the cationic starch and possibly of the hemiacetal groups of its products of acid hydrolysis.

Abstract: Dielectric liquids are prepared by (a) Friedel-Crafts condensing at least one aromatic halide with at least one aromatic compound in the presence of a catalytically effective amount of ferric chloride, and thereafter deliberately avoiding any downstream destruction/neutralization and/or washing of such ferric chloride catalyst, (b) optionally, removing unreacted reactants from the medium of reaction, and (c) recovering from such medium of reaction a purified dielectric liquid; the subject process is thus environmentally improved by avoiding the generation of aqueous solutions containing contaminating amounts of objectionable organic compounds.

Abstract: The cetane numbers of directly distilled diesel fuels are significantly improved by intimately contacting same with an effective amount of hydrogen peroxide in the presence of a carboxylic acid, or with an effective amount of a percarboxylic acid either in the presence or absence of hydrogen peroxide.

Abstract: A process for the manufacture of amines by reacting at an elevated temperature an olefin selected from a monoolefin, the alcohol corresponding to its hydration, or a mixture of the monoolefin and the alcohol with ammonia or a primary or secondary amine in the presence of a catalyst and a solvent, said catalyst being ammonium sulfate of a double sulfate of ammonium and a transition metal.

Abstract: A liquid composition comprising a mixture of isomers of essentially diisocyanates having the diphenylmethane structure, the distribution by weight of isomers in the composition for each 100 parts by weight of the composition being:32 to 55% of the 4,4' isomer,30 to 45% of the 2,4' isomer,5 to 12% of the 3,4' isomer,4 to 10% of the 2,2' isomer, and2 to 5% of the 2,3' isomer;and the method of making the composition by first reacting a benzyl halide with benzene, followed by nitration, hydrogenation, and phosgenation.

Abstract: Heteropolymetallic clusters of the formula Pd.sub.2 (Fe).sub.x (CO).sub.4 [CO(NO).sub.2 ].sub.y [bis(diphenylphosphine)methane].sub.2 wherein x is 1 or 2 and y is 0 or 1; x=2 when y=1 and x=1 when y=0; to the method of making such clusters by reacting Pd.sub.2 Cl.sub.2 [bis(diphenylphosphine)methane] with MnFe(CO).sub.3 Z wherein M is an alkaline metal and Z is CO (n=2) or NO (n=1); and to the novel catalysts formed utilizing said clusters.