摘要:
The invention is a new process to produce polyparaphenylene vinylene or polyparathienylene vinylene polymers using a sulfonium-based polyelectric precursor. This precursor is treated directly with acid to obtain the polymers required. These polymers have high molecular weights and are particularly advantageous in the plastics transformation field.
摘要:
It has an inlet and an outlet, a bag made from a flexible, deformable material insulating the inlet from the outlet, a liquid contained in the bag on the outlet side, a transfer tube with openings on its side wall and closed by an end plug. Diffusers are positioned on the transfer tube with a given spacing, so as to leave a passage for a gas between two successive diffusers, each diffuser comprising a frame externally surrounded by an elastomer ring.
摘要:
Composite product, useful notably as a catalyst, comprising a coordination complex of a metal, notably of a transition metal, fixed to a support, wherein this support is formed of a solid mineral material, insoluble in organic solvets, and is covered at least partly by a polysiloxane, on which the coordinates of these complexes are grafted. This catalyst is stable in gaseous as well as in liquid media, and is useful for the hydrogenation of olefins in homogeneous and heterogeneous phases as well.
摘要:
A supported Lewis acid catalyst system for catalyzing hydrocarbon conversion reactions including cationic polymerization, alkylation, isomerization and cracking reactions is disclosed, wherein the catalyst system comprises an inorganic oxide support having immobilized thereon a least one strong Lewis acid comprising at least one metal salt of a strong Bronsted acid wherein the metal is selected from the group consisting of aluminum, boron gallium, antimony, tantalum, niobium, yttrium, cobalt, nickel, iron, tin, zinc, magnesium barium strontium, calcium, tungsten, molybdenum and the metals of the lanthanide series and wherein the strong Bronsted acid is selected from the group consisting of mineral and organic acids stronger than 100% sulfuric acid.
摘要:
Control device for a watch movement having a part rotatably movable around an axis A. The device is associated with a watch case (11) and has a lock (25) actuatable from outside the watch. The lock is movably mounted in translation to the periphery of the watch case (11). The device also has a movably mounted plate (30) which is rotatable around an axis D inside the watch case and is kinematically connected to the lock. An arm (34) is pivotable around and axis B, whose first end is placed on the plate in such a way that it is freely rotatable around an axis C non-merging with the axis D and whose other end is fixed to the part for driving the movement.
摘要:
A process for the polymerization of chloroprene or of a mixture of chloroprene and of up to 20% by weight of a copolymerizable monomer, in aqueous emulsion in the presence of radical initiators, at a temperature of between 5° C. and 70° C., characterized in that the polymerization is carried out in the presence of one or more copolymerizable surfactants in agreement with the formula described below (I) R3—Z—CO—C(R1)═C(R2)—COOM (I) where: R3 is a saturated or unsaturated, linear or branched and aliphatic or aromatic Cn hydrocarbonaceous chain with n from 10 to 20; R1 and R2, which are identical or different, are chosen from H or a C1-C3 alkyl radical; Z is chosen from —O— and —NH—; M is chosen from alkali metals or NH4.
摘要:
A supported Lewis acid catalyst system for catalyzing hydrocarbon conversion reactions including cationic polymerization, alkylation, isomerization and cracking reactions is disclosed, wherein the catalyst system comprises an inorganic oxide support having immobilized thereon a least one strong Lewis acid comprising at least one metal salt of a strong Bronsted acid wherein the metal is selected from the group consisting of aluminum, boron gallium, antimony, tantalum, niobium, yttrium, cobalt, nickel, iron, tin, zinc, magnesium barium strontium, calcium, tungsten, molybdenum and the metals of the lanthanide series and wherein the strong Bronsted acid is selected from the group consisting of mineral and organic acids stronger than 100% sulfuric acid.
摘要:
Control device for a watch movement having a part rotatably movable around an axis A. The device is associated with a watch case (11) and has a lock (25) actuatable from outside the watch. The lock is movably mounted in translation to the periphery of the watch case (11). The device also has a movably mounted plate (30) which is rotatable around an axis D inside the watch case and is cinematically connected to the lock. An arm (34) is pivotable around and axis B, whose first end is placed on the plate in such a way that it is freely rotatable around an axis C non-merging with the axis D and whose other end is fixed to the part for driving the movement.
摘要:
A supported Lewis acid catalyst, which comprises an inorganic oxide substrate having immobilized thereon at least one Lewis acid and a modifying agent containing at least one functional moiety capable of reacting with surface hydroxyl groups originally present on said substrate and which is effective as a catalyst for hydrocarbon conversion reactions including cationic polymerization, alkylation, isomerization and cracking reactions is disclosed.
摘要:
A supported Lewis acid catalyst, which comprises an inorganic oxide substrate having immobilized thereon at least one Lewis acid and a modifying agent containing at least one functional moiety capable of reacting with surface hydroxyl groups originally present on said substrate and which is effective as a catalyst for hydrocarbon conversion reactions including cationic polymerization, alkylation, isomerization and cracking reactions is disclosed.