Abstract: The present invention relates to a process for preparing CNTs by bringing a carbon source into contact with a multivalent metal and/or metal-oxide-based catalyst deposited on an inorganic substrate having a BET specific surface area of greater than 50 m2/g. The CNTs obtained may be used as agents for improving the mechanical and electrical conductivity properties in polymeric compositions.

Abstract: The invention relates to a method for synthesis of carbon nanotubes of the highest carbon purity by the process of vapour phase chemical deposition. The nanotubes produced can be used to advantage in all know applications of carbon nanotubes.

Abstract: The invention relates to a method for filling a receptacle (200) with carbon nanotubes from another receptacle (106) whereby the CNTs are passed from one receptacle to the other by means of a coupling (300) comprising a double-valve device (30), each valve being coupled to one of the receptacles, the valves (31, 32) closing independently and tightly and being openable only when they are coupled to one another.

Abstract: The invention relates to a method for synthesis of carbon nanotubes of the highest carbon purity by the process of vapour phase chemical deposition. The nanotubes produced can be used to advantage in all know applications of carbon nanotubes.

Abstract: A subject of the present invention is a process for producing carbon nanotubes, the process comprising: a) the synthesis of alcohol(s) by fermentation of at least one vegetable matter and optionally the purification of the product obtained; b) the dehydration of the alcohol or alcohols obtained in a) in order to produce, in a first reactor, a mixture of alkene(s) and water and optionally the purification of the product obtained; c) the introduction, in particular the introduction into a fluidized bed, in a second reactor, of a powdery catalyst at a temperature ranging from 450 to 850° C.

Abstract: The present invention relates to a process for preparing CNTs by bringing a carbon source into contact with a multivalent metal and/or metal-oxide-based catalyst deposited on an inorganic substrate having a BET specific surface area of greater than 50 m2/g. The CNTs obtained may be used as agents for improving the mechanical and electrical conductivity properties in polymeric compositions.

Abstract: The impact-resistant thermoplastic compositions comprising (A) a rigid thermoplastic methacrylic polymer or copolymer matrix P containing mostly methyl methacrylate units, (B) at least one impact-modifying additive and (C) at least one elastomer copolymer which contains grafting sites, at least on pendant chains, and is obtained from at least one vinylaromatic monomer (C1) and from at one monomer chosen from the monomers (C2): C1-C15 linear or branched alkyl acrylates, C1-C4 alkoxyalkyl acrylates and aralkyl acrylates, dienes (C3) and ethylenically unsaturated monomers (C4) having one or more pendant initiating functional groups, the said copolymer (C) being grafted by thermoplastic polymer groups P and being dispersed in the matrix (A) in the form of nodules, which can be called “particles”, from 10 nm to 500 nm in size and able to have a droplet, capsule-type monoinclusion and/or salami-type multi-inclusion morphology.

Abstract: The invention concerns thermoplastic impact-resistant compositions comprising (A) a thermoplastic methacrylic polymer of copolymer (P) including for the major part methyl methacrylate units, (B) at least an impact resistance enhancing additive and at least a grafted elastomeric polymer (C) bearing thermoplastic methacrylic (co)polymer groups (P) grafted at least in pendant position on an elastomeric copolymer (C°), said elastomeric copolymer (C°) being obtained from (i) at least a vinylaromatic monomer (C1), (ii) at least a monomer (C2) selected among the C1-C15 linear or branched alkyl acrylates, alkoxyalkyl acrylates wherein the alkyl group(s) have 1 to 4 carbon atoms and aralkyl acrylates wherein the alkyl group(s) has/have 1 to 15 carbon atoms and/or at least a diene monomer (C3) and (iii) optionally at least an ethylenically unsaturated monomer (C4) with pendant initiator function(s), said monomer(s) (C4) being necessary in the absence of monomer (C3), said grafted elastomeric copolymer (C) being

Abstract: Imidation-modified MMA (co)polymers, characteristically having a Tg from 20.degree. to 30.degree. C. higher than the Tg of the corresponding unmodified MMA (co)polymer, are produced by reacting an amine, e.g., methylamine or cyclohexylamine, with a suspension, in a hydrophobic nonsolvent reaction medium, of beads of such MMA polymer/copolymer.

Abstract: In a first step of this process an elastomer latex is prepared in aqueous emulsion in the presence of at least one ionic surfactant and at least one ethylenically unsaturated monomer; then in a second step at least one vinyl monomer, which is insoluble in water or sparingly soluble in water, is added to the latex thus obtained and the ionic charges introduced by the said latex are neutralised by adding to the mixture of latex and monomer at least one transfer agent carrying ionic charges opposite to those of the surfactant used in the first step, in order to effect the transfer of particles of the latex into the vinyl monomer; then in a third step the aqueous phase is separated from the organic phase comprising the latex and the vinyl monomer; and in a fourth step the bulk polymerisation of the organic phase is carried out in such a way as to obtain the cast sheet after cooling and release from the mould.

Abstract: (Meth)acrylic/glutarimide copolymers, well suited, e.g., for optical applications, having enhanced glass transition temperatures (Tg), are prepared by salifying the acid functions of (meth)acrylic ester/(meth)acrylic acid copolymers, and then imidifying such "intermediate" salified copolymers into the subject (meth)acrylic/glutarimide polymers.

Abstract: The application discloses a functionalized multiblock macromonomer of formula: ##STR1## or of formula: ##STR2## in which formulae: each of the blocks A, B and C represents a sequence of a monomer chosen from the acrylic, vinylaromatic, methacrylic, diene, vinylpyridine, vinylpyrrolidone, alkylene oxide, lactam, lactone and maleimide monomer classes, on condition that at least one of the blocks A and C is chosen from a different class to that of block B and that at least one of the blocks A, B or C is a (meth)acrylic sequence,m, n and p are integers representing the number of monomer units in the sequence under consideration, such that 3.ltoreq.n.ltoreq.1000, 0.ltoreq.m.ltoreq.1000 and 0.ltoreq.p.ltoreq.1000, on condition that m and p are not 0 at the same time, andF is a group terminated by O.sup.-, by OH, by an .alpha.,.beta.-ethylenic unsaturation, or by an oxirane groups.

Abstract: Imidation-modified MMA (co)polymers, characteristically having a Tg from 20.degree. to 30.degree. C. higher than the Tg of the corresponding unmodified MMA (co)polymer, are produced by reacting an amine, e.g., methylamine or cyclohexylamine, with a suspension, in a hydrophobic nonsolvent reaction medium, of beads of such MMA polymer/copolymer.

Abstract: A multilayer interpolymer material of an elastomeric inner phase polymerized from (a) 50-99.9 parts of at least one among: conjugated dienes and alkyl and aralkyl acrylates, (b) 0-49.9 parts of at least one copolymerizable monomer, (c) 0.05-8 parts of at least one crosslinking monomer, and (d) 0.05-6 parts of at least one grafting monomer, and a nonelastomeric outer phase, polymerized from (a) 50-99.9 parts by weight of at least one among: alkyl methacrylates, vinyl aromatic hydrocarbons and unsaturated nitriles, (b) 0.1-50 parts of at least one copolymerizable monomer, and (c) 0-5 parts of at least one chain-limiting agent, the parts being given by weight, it being possible for the said polymer to comprise a nonelastomeric or else elastomeric core phase without grafting and crosslinking monomers. Two populations of particles of mean diameter of approximately 40-150 nm and approximately 160-500 nm respectively are mixed in given ratios. This improves the impact strength of the resultant matrices.