Pentenes are alkenes with chemical formula C₅H₁₀. Each contains one double bond within its molecular structure. There are a total of six different compounds in this class, differing from each other by whether the carbon atoms are attached linearly or in a branched structure, and whether the double bond has a cis or trans form.
A process for the preparation of polyolefins having a bi- or multimodal molecular weight distribution, the process comprising the steps of: (i) contacting an olefin monomer and a first co-reactant with a catalyst system in a first reaction zone under first polymerization conditions to produce a product comprising a first polyolefin having a first molecular weight distribution; and (ii) contacting an olefin monomer and a second co-reactant with a catalyst system in a second reaction zone under second polymerization conditions to produce a product comprising a second polyolefin having a second molecular weight distribution different from the first molecular weight distribution; wherein the first and second polyolefins are mixed together, wherein one of the co-reactants is hydrogen and the other is a comonomer selected from butene, methylpentene, hexene or octene, and wherein each catalyst system comprises (a) a metallocene catalyst component comprising a bis tetrahydroindenly compound of the general formula (IndH4)2R''MQ2 in which each Ind is the same or different and is indenyl or substituted indenyl, R'' is a bridge which comprises a C1-C4 alkylene radical, a dialkly mernamium or silicon or siloxane, or an alkylphosphine or amine radical, which bridge is substitued or unsubstituted, M is a Group IV metal or vanadium and each Q is hydrocarbyl having 1 to 20 carbon atoms or halogen; and (b) a cocatalyst which activates the catalyst component.
A butyl polymer having improved processability is described, together with a process for production thereof. The butyl polymer derived from a reaction mixture which contains: (i) a monomer mixture comprising a C4 to C7 monoolefin monomer (preferably isobutylene) and a C4 to C14 multiolefin monomer (preferably isoprene); (ii) a multiolefin cross-linking agent (preferably divinyl benzene); and (iii) a chain transfer agent (preferably diisobutylene (2,2,4-trimethyl-1-pentene)). The subject butyl polymer has an improved balance of cold flow, filler dispersion, extrusion rate and die swell.
The production of ultrafine metalcarbide powders from polymeric powder and metallic precursor powder starting materials is disclosed. In certain embodiments, the polymeric powder may comprise polypropylene, polyethylene, polystyrene, polyester, polybutylene, nylon, polymethylpentene and the like. The metal precursor powder may comprise pure metals, metal alloys, intermetallics and / or metal-containing compounds such as metal oxides and nitrides. In one embodiment, the metal precursor powder comprises a silicon-containing material, and the ultrafine powders comprise SiC. The polymeric and metal precursor powders are fed together or separately to a plasmasystem where the feed materials react to form metal carbides in the form of ultrafine particles.
In order to maximize the production of propylene when the external supply of ethylene is limited, the C4 cut from a hydrocarboncracking process is first subjected to autometathesis prior to any isobutylene removal and without any ethylene addition. This favors the reactions which produce propylene and pentenes. The ethylene and propylene produced are then removed leaving a stream of the C4's and heavier components. The C5 and heavier components are then removed leaving a mixture of 1-butene, 2-butene, isobutylene, and iso-and normal butanes. The isobutylene is next removed preferably by a catalytic distillation hydroisomerization de-isobutyleneizer. The isobutylene-free C4 stream is then mixed with the product ethylene removed from the autometathesis product together with any fresh external ethylene needed and subjected to conventional metathesis producing additional propylene.
The invention relates to a metal-organic framework supported heteropoly acid catalyst for synthesizing glutaraldehyde and a production method of the metal-organic framework supported heteropoly acid catalyst. The catalyst is prepared by a one-step synthesis method, namely a heteropoly acid component with catalytic oxidation activity is introduced into a duct of a metal-organic framework material UiO-66 in the process of synthesizing the metal-organic framework material UiO-66. The catalyst has the characteristics that the catalyst has a crystal framework structure, the active component is highly dispersed, and the heteropoly acid is over-high in load. The catalyst is applied to catalytic selective oxidation reaction of cyclopentene, so that the selectivity and the yield of the glutaraldehyde is greatly improved; the numerical value is much higher than the reported homogeneous catalysis level; and the metal-organic framework supported heteropoly acid catalyst has important industrial application value.