摘要:
Bidentate catalyst systems and the methods or forming such are described herein. The catalyst systems generally are compounds having the general formula: where R, R1, R2 and R3 are optional and independently selected from hydrogen, C1 to C20 alkyl groups or C6 to C20 aryl groups, A' and A' are independently selected from coordination groups, M is a Group 4 or 5 transition metal, X is selected from halogens, alkyl groups, aromatic groups or combinations thereof and n is less than 4.
摘要:
[0035] A process for the preparation of a hydroperoxide functionalized rubber compound by the conversion of triplet state oxygen to singlet state oxygen in the presence of oxygen and a light-induced photoreductant. A dispersion of an unsaturated rubber component in a carrier solvent is introduced into a reactor containing a permeable catalyst bed comprising a light-induced photoreductant component supported on a particulate substrate component and passed through the catalyst bed. A gaseous oxidizing agent is passed through the catalyst bed in contact with the rubber-containing dispersion. The catalyst bed is irradiated with electromagnetic light radiation in the ultraviolet or visible light range at an intensity sufficient to convert triplet oxygen in the oxygenated rubber component to singlet oxygen. The oxygenated rubber component is then recovered from the reactor. The reactor can comprise a tubular outer shell and a tubular inner member having a permeable wall defining an annular space containing photoreductant-supported substrate material. The oxidizing agent is introduced into the inner member and radially dispersed outward from this member into contact with the supported photoreductant. The solvent rubber component is concurrently passed into contact with the catalyst bed.
摘要:
Disclosed is a process for preparing an olefinic polymer comprising contacting at least one olefinic C3+ monomer and a catalyst composition comprising a Ziegler-Natta catalyst, dicyclopentyl dimethoxysilane as a first electron donor, and a second electron donor selected from the group consisting of methyl trimethoxysilane, methyl triethoxysilane, dimethyl dimethoxysilane, and mixtures thereof, under reaction conditions suitable to form an olefinic polymer. The polymer prepared using this method may exhibit significantly broadened molecular weight distribution than that achieved using any of the silane compounds alone, and may also exhibit desirable melt flow characteristics and xylene solubles levels.
摘要:
Methods of extending the life of dehydrogenation catalyst are described herein. For example, one embodiment includes providing a catalytic dehydrogenation system, wherein the catalytic dehydrogenation system includes at least one reaction vessel, the at least one reaction vessel loaded with a dehydrogenation catalyst including an alkali metal enhanced iron oxide, contacting the dehydrogenation catalyst with a feedstream including an alkyl aromatic hydrocarbon to form a vinyl aromatic hydrocarbon and contacting the feedstream with a catalyst life extender, wherein the catalyst life extender includes cesium.
摘要:
A process for the production of ethylbenzene by the ethylation of benzene in the critical phase in a reaction zone containing a molecular sieve aromatic alkylation catalyst comprising cerium-promoted zeolite beta. A polyethylbenzene is supplied into the reaction zone and into contact with the cerium-promoted zeolite beta having a silica/alumina mole ratio within the range of 20-500. The reaction zone is operated at temperature and pressure conditions in which benzene is in the supercritical phase to cause ethylation of the benzene and the transalkylation of polyethylbenzene and benzene in the presence of the zeolite beta catalyst. An alkylation product is produced containing ethylbenzene as a primary product with the attendant production of heavier alkylated byproducts of no more than 60 wt.% of the ethylbenzene. The alkylation reaction zone is operated under conditions providing a composite byproduct yield of propyl benzene and butyl benzene relative to ethylbenzene, which is no more than one half of the corresponding yield byproduct for zeolite beta promoted with lanthanum. The production of ethylbenzene in the critical phase alkylation reaction zone is attended by recycle of a polyalkylated aromatic component of the reaction product back to the reaction zone.
摘要:
Disclosed is an improvement in a process of preparing cyclohexenyl and alkenyl aromatic compounds, such as styrene, that enables economical and convenient removal of nitrogen compounds. The nitrogen compounds can be stabilizers or neutralizers or derived from stabilizers or neutralizers added to prevent styrene homopolymerization. The nitrogen compounds are removed from, in the case of styrene production, the benzene fraction that results from dehydrogenation of ethylbenzene. Because of the preferential solubility of nitrogen compounds in water, a majority of such compounds can be removed by intimately contacting the benzene fraction with sufficient water, at an appropriate point in the rocess, and then removing most or all of the water with the entrained nitrogen compounds.
摘要:
A polymer blend and a method of making the same are provide. The polymer blend includes an ethylene-propylene (C2-C3) random copolymer and a modifier selected from the group consisting of a metallocene-catalyzed polyethylene-based copolymer, a metallocene-catalyzed polyethylene-based terpolymer, and a syndiotactic polypropylene homopolymer. The polymer blend may also include an organic peroxide for visbreading the polymer blend. An end use article is made from the foregoing polymer blend. The end use article may be, for example, a film, an injection molded article, a compression molded, a thermoformed article, and a fiber. The end use article is desirably a film having an Elmendorf tear strength of at least about 300 g/ply in the machine and transverse directions.
摘要:
The present invention provides a process for control of desired properties in the polymer product. The catalyst system used in the process includes a supported metallocene catalyst precursor in combination with an oxyorganoaluminum. The process can be applied to the co-polymerization of propylene and ethylene. The randomness of the ethylene incorporation of the co-polymer product is increased as the amount of ethylene in the feed is increased. The amount of ethylene in the feed is up to 6 wt% with a resulting amount of ethylene incorporated into the copolymer product up to 4 mole %.
摘要:
Disclosed is a method to safely terminate a runaway reaction within a reaction vessel, comprising: sensing an increase in pressure in the reaction vessel, opening a barrier blocking a flow path into the reactor, wherein the barrier opening is achieved via a mechanical response to the sensed increase in pressure, and injecting a kill agent into the reaction vessel via the opened flow path, thereby terminating the reaction. Also disclosed is a system for performing the method. The system functions without an external electrical source and is therefore compliant with ASME standards.