Abstract: Methods and systems are provided for a dry silicone gel. The dry silicone gel comprises a base polymer having a vinyl-silicone group, a crosslinker, and a chain extender. The dry silicone gel may be made by reacting (a) a first set of components comprising a base polymer having a vinyl-silicone group and an addition cure catalyst with (b) a second set of components comprising a crosslinker, a chain extender, and additional base polymer. In certain circumstances, the base polymer and additional base polymer are vinyl-terminated polydimethylsiloxane.

Abstract: Methods and systems are provided for a dry silicone gel in a closure or interconnect system. The dry silicone gel may be made by reacting a crosslinker, a chain extender, and a vinyl-terminated polydimethylsiloxane. The reaction may be conducted in the presence of a catalyst. In certain embodiments, the dry silicone gel may comprise: (1) a hardness between 100 g and 300 g, (2) a stress relaxation between 30% and 60% when subjected to a deformation of 50% of the original size of the gel, (3) a compression set between 4% and 20% after 50% strain has been applied to the gel for 1000 hours at 70° C., and/or (4) less than 10% oil bleed out under compression of 1.2 atm after 60 days at 60° C.

Abstract: Methods and systems are provided for a dry silicone gel in a closure or interconnect system. The dry silicone gel may be made by reacting a crosslinker, a chain extender, and a vinyl-terminated polydimethylsiloxane. The reaction may be conducted in the presence of a catalyst. In certain embodiments, the dry silicone gel may comprise: (1) a hardness between 100 g and 300 g, (2) a stress relaxation between 30% and 60% when subjected to a deformation of 50% of the original size of the gel, (3) a compression set between 4% and 20% after 50% strain has been applied to the gel for 1000 hours at 70° C., and/or (4) less than 10% oil bleed out under compression of 1.2 atm after 60 days at 60° C.

Abstract: Methods and systems are provided for a dry silicone gel. The dry silicone gel comprises a base polymer having a vinyl-silicone group, a crosslinker, and a chain extender. The dry silicone gel may be made by reacting (a) a first set of components comprising a base polymer having a vinyl-silicone group and an addition cure catalyst with (b) a second set of components comprising a crosslinker, a chain extender, and additional base polymer. In certain circumstances, the base polymer and additional base polymer are vinyl-terminated polydimethylsiloxane.

Abstract: A composition is disclosed that includes at least one polyolefin, at least one organic peroxide, and an antioxidant mixture of a composition of at least one polyolefin, at least one organic peroxide, and an antioxidant mixture. The antioxidant mixture has at least one fast radical scavenger selected from the group consisting of low hindered phenols, low hindered thiophenols, low hindered thiobisphenols, aliphatic amines, aromatic amines, NOR HALS, hydroxylamines, and mixtures thereof, and at least one long term stabilizer selected from the group consisting of low hindered phenols, highly hindered phenols, thiosynergists, aliphatic amines, aromatic amines, HALS, hydroxylamines, and mixtures thereof. The preferred polyolefin is a homopolymer of ethylene or a copolymer of ethylene and the compositions are useful in insulating media for medium and high voltage wire and cable applications.

Abstract: A catalyst carrier including a surface layer of oxygen-donating oxide, particularly cerine, is disclosed. A catalytic phase deposited on said carrier generally includes platinum and rhodium, thus forming a catalytic system for exhaust pipes, said catalytic phase being readily recoverable by simple leaching.

Abstract: Silicon carbide foam useful as a catalyst support has a BET specific surface area of at least 5 m2/g, and a compression strength exceeding 0.2 MPa. The foam is prepared by impreganting an organic foam with a suspension of silicon in a resin containing a cross-linking agent, incompletely cross-linking the resin, carbonizing the foam and resin, and carburizing the silicon.

Abstract: An organohalide-flame retardant polymer containing as a stabilizer blend: a) an acid scavenger, for example a hydrotalcite or an amorphous basic aluminum magnesium carbonate; b) a heat stabilizer comprising an organotin compound; and c) a polyhydroxyaliphatic costabilizer.

Abstract: The invention relates to a silicon carbide or metal carbide foam to be used as a catalyst or catalyst support for the chemical or petrochemical industry or for silencers, as well as the process for producing the same. The foam is in the form of a three-dimensional network of interconnected cages, whose edge length is between 50 and 500 micrometres, whose density is between 0.03 and 0.1 g/cm3 and whose BET surface is between 20 and 100 m2/g. The carbide foam contains no more than 0.1% by weight residual metal and the size of the carbide crystallites is between 40 and 400 Angstroms. The production process consists of starting with a carbon foam, increasing its specific surface by an activation treatment using carbon dioxide and then contacting the thus activated foam with a volatile compound of the metal, whose carbide it is wished to obtain.

Abstract: SiC foam-based catalyst carrier in the form of a moulded part having walls reinforced with a SiC skin having mechanical characteristics higher than those of the foam, this skin allowing the carrier to be handled and used without damage.

Abstract: A catalyst for chemical and petrochemical reactions and a process for its production. The catalyst comprises an oxide of one of the transition metals, rare earth elements, or actinide elements, e.g., molybdenum, having on its surface carbides and oxycarbides, the core being the metal or the metal oxide. In the process for catalyst production, the reaction gas mixture containing carbon products is passed onto the oxide, leading to a progressive carburization of the surface of the oxide and to a progressive increase in the efficiency of the catalyst.

Abstract: The invention concerns a process for preparing a silicon carbide foam consisting of attacking a polyurethane foam with an alkaline solution, impregnating it, after rinsing and drying, with a suspension of silicon powder in an organic resin, heating progressively to polymerise the resin, carbonising the polyurethane foam and resin, and finally carburising the silicon contained in the resin suspension by means of the carbon originating from the carbonisation of the foam and resin.The foams obtained are characterised by a high microporosity and a mesoporosity which is variable according to the carburising temperature.The invention finds an application in the manufacture of catalyst carriers for exhaust chambers and filters for diesel engines.

Abstract: A process for preparing a silicon carbide foam by impregnating a polyurethane foam with a suspension of silicon powder in an organic resin, heating progressively to polymerize the resin, heating further to carbonize the polyurethane foam and resin, and finally further heating to carburize the silicon contained in the resin suspension by means of carbon obtained from the carbonization of the foam and resin. The foam obtained is characterized by high macroporosity and a mesoporosity which is variable according to the carburizing temperature.

Abstract: A process for the production of a metal carbide having a BET specific surface area of 10 to 200 m.sup.2 /g, in which a reaction mixture including carbon having a specific surface area of at least 200 m.sup.2 /g and a compound of the metal to be reacted with the carbon which is volatile at 900.degree. C. to 1400.degree. C. is introduced into a reactor, the reactor is scavenged by a flow of inert gas and the reaction mixture is heated under the flow of inert gas at 900.degree. to 1400.degree. C. for a time sufficient to volatilize the metal, reduce the volatilized metal compound to the metal with and carburize the metal by reaction with carbon, forming the metal carbide. The metal carbide formed is cooled under the flow of inert gas.

Abstract: Thermally stable ceric oxide-based compositions, well suited as catalysts/catalyst supports for a wide variety of reactions, notably for the catalytic conversion of exhaust gases emanating from internal combustion engines, comprise particulates of immixture of a major amount of ceric oxide with at least one other metal oxide of magnesium, gallium, boron, scandium, or mixture thereof, and having a specific surface greater than 10 m.sup.2 /g after calcination at 800.degree. C.

Abstract: Methods and systems are provided for a dry silicone gel. The dry silicone gel comprises a base polymer having a vinyl-silicone group, a crosslinker, and a chain extender. The dry silicone gel may be made by reacting (a) a first set of components comprising a base polymer having a vinyl-silicone group and an addition cure catalyst with (b) a second set of components comprising a crosslinker, a chain extender, and additional base polymer. In certain circumstances, the base polymer and additional base polymer are vinyl-terminated polydimethylsiloxane.

Abstract: Methods and systems are provided for a dry silicone gel. The dry silicone gel comprises a base polymer having a vinylsilicone group, a crosslinker, and a chain extender. The dry silicone gel may be made by reacting (a) a first set of components comprising a base polymer having a vinylsilicone group and an addition cure catalyst with (b) a second set of components comprising a crosslinker, a chain extender, and additional base polymer. In certain circumstances, the base polymer and additional base polymer are vinyl-terminated polydimethylsiloxane.