110 results about "Ethylene polymerization" patented technology

The invention discloses a method for producing multimodal polyethylene through series connection of multiple reactors, and belongs to the field of olefin polymerization. The low-molecular-weight or medium-molecular-weight ethylene polymer is produced through polymerization in the first reactor, the obtained product enters the intermediate treatment unit to remove hydrogen, and then part of the product is shunted to enter the second reactor to be mixed with the ultra-high-molecular-weight ethylene polymer produced through ethylene polymerization in the second reactor; all polymers of the second reactor are returned to the intermediate treatment unit, and the rest products after hydrogen removal enter a third reactor and are mixed with high-molecular-weight ethylene polymers generated by copolymerization of ethylene and comonomers in the third reactor to generate multimodal polyethylene. The multimodal polyethylene produced by the method is wide in molecular weight distribution, and the molecular weight of ultra-high molecular weight polyethylene is flexible to regulate and control. According to the invention, material circulation between the third reactor and the second reactor is adopted, molecular chain-level mixing among the components is achieved, the compatibility is good, and the mechanical property is more excellent.

The application discloses an ethylene and alpha-olefin copolymerization evaluation test device, which comprises an olefin mixed gas distribution device, a polymerization reactor, a temperature control unit, a pressure control unit and a stirring device. The polymerization reactor is connected with the olefin mixed gas distribution device, the temperature control unit is connected with the polymerization reactor, and the pressure control unit is connected with the polymerization reactor. The stirring device comprises a stirring shaft and a stirring paddle. The stirring shaft is a hollow structure with a gas flow pipeline inside. One end of the stirring shaft penetrates through a cover of the polymerization reactor and is provided with a gas inlet. The other end of the stirring shaft is connected with the stirring paddle. The stirring paddle is arranged at the bottom of the polymerization reactor. At least one gas outlet is arranged on the stirring paddle. The ethylene and alpha-olefin copolymerization evaluation test device can increase the contact amount of ethylene and alpha-olefin with a catalyst. The ethylene and alpha-olefin copolymerization evaluation test device can be used for evaluating ethylene polymerization, and the catalyst activity can be accurately evaluated.

The invention discloses a catalyst component for olefin polymerization, a catalyst, a preparation method and application, and relates to the technical field of olefin polymerization catalysts. The catalyst component comprises reaction products of the following components: a magnesium-containing compound solution, an organic anhydride compound, a titanium compound, an acetate compound, a first alcohol compound and an aromatic ester compound, in the catalyst component, the molar ratio of the magnesium element to the organic anhydride compound to the titanium compound to the acetate compound to the first alcohol compound to the aromatic ester compound is 1: (0.01-1): (2-30): (0.01-10.0): (0.05-10.0): (0.01-5.0). The catalyst component prepared by the preparation method provided by the invention is concentrated in particle size distribution, the catalyst containing the catalyst component has higher polymerization activity, the hydrogen regulation sensitivity under the condition of high hydrogen-ethyl ratio is greatly improved, the hydrogen regulation sensitivity under the condition of low hydrogen-ethyl ratio is moderate, and the catalyst component is suitable for industrial production. The catalyst can catalyze ethylene polymerization to obtain powder particles with high bulk density, the content of fine powder with the size smaller than 75 microns in the polymerized powder is greatly reduced, and almost no fine powder exists.

The present disclosure provides a process. In an embodiment, the process includes introducing an antifoulant into an ethylene feed of a reactor system. The reactor system includes the ethylene feed, a hyper-compressor, a preheater and a polymerization reactor. The ethylene feed is located upstream of the hyper-compressor. The antifoulant consists of an inhibitor, molecular oxygen, and optionally a solvent. As the ethylene feed is located upstream of the hyper-compressor, the process includes introducing the antifoulant into the ethylene feed upstream of the hyper-compressor. The process further includes adding a free radical initiator to the polymerization reactor. The process further includes polymerizing the ethylene in the polymerization reactor under high pressure free-radical polymerization conditions, and forming an ethylene-based polymer.

The present application relates to a kind of diimine ligand with the general structure shown in formula L, the post-transition metal catalyst prepared by its coordination and its preparation method and application, wherein R1-R6 are independently selected from H, C1-C6 alkyl, C1-C6 alkoxy, C6-C 12 Aryl or halogen. The present application constructs diimine post-transition metal catalyst with different chemical environment of bimetallic active site and rigid parent ring skeleton structure, not only improves catalytic activity and thermal stability, but also can be used for preparing bimodal UHMWPE by ethylene polymerization.

This invention relates to the field of catalyst synthesis technology, and more particularly to an alkoxytitanium non-metallocene catalyst for preparing polyethylene wax and its preparation method. The alkoxytitanium catalyst prepared by this invention can directly carry out ethylene polymerization. The polymerization process is simple, requires only a small amount of alkyl aluminum halides for impurity removal, and exhibits high catalytic activity. It requires no additional organoboron compounds or methylchlorooxyalkane, nor does it require chain transfer agents to adjust molecular weight. It has a novel structure, outstanding catalytic activity, and a simple synthesis process with diverse ligand designs. By designing different types of ligands, the molecular weight and activity of the polymer can be effectively improved, achieving precise control over catalyst activity and selectivity, thereby obtaining olefin polymers with specific structures and properties. This characteristic provides broad prospects for the preparation of polymer materials with specific properties and applications.

The present invention provides a catalyst composition and a preparation method therefor, and a preparation method for high melt strength polyethylene. The catalyst composition comprises a main catalyst and a co-catalyst; the co-catalyst comprises an alkylaluminum compound and a pyridine compound; and the main catalyst is prepared by reacting a magnesium compound, a silicon compound and a titanium compound in a molar ratio of 1:0.1-10:0.05-3. When catalyzing ethylene polymerization, the catalyst composition of the present invention can significantly improve the melt strength of a polymerization product.

This invention discloses an asymmetric (α-diimine) nickel-olefin catalyst based on ethylene acenaphthene as its framework, its preparation method, and its applications. The structural formula of the catalyst is shown in Formula (I), where X is chlorine or bromine. The catalyst has a simple preparation process and exhibits results contrary to conventional experimental observations when catalyzing ethylene polymerization: larger substituents lead to higher crystallinity in the polymerization product. Furthermore, this type of catalyst also exhibits good thermal stability and polymerization activity, showing promising prospects for industrial applications. Formula (I)

The application relates to the technical field of olefin polymerization, and discloses an ether metal complex and a preparation method and application thereof. The structural formula of the ether metal complex is shown in formula (I): wherein R1, R2, R3 and R4 are each independently selected from one of hydrogen, C1-C10 alkyl and halogen; X is each selected from O or S; and M is selected from IVB group metal. The ether metal complex is applied to ethylene polymerization as a catalyst, has high reactivity, good thermal stability, shows extremely strong control performance on the molecular weight of polyethylene wax, and highly linear low-molecular-weight polyethylene is obtained. Formula (I)

The invention discloses an optimization method, device and equipment for polyethylene polymerization parameters and a storage medium, and belongs to the technical field of material design. The optimization method comprises the following steps: acquiring a plurality of polyethylene polymerization parameter groups and polyethylene performance index requirements; determining a polyethylene performance index prediction model corresponding to the polyethylene performance index demand; determining a plurality of predicted polyethylene performance index values based on the polyethylene performance index prediction model and a preset polyethylene polymerization constraint condition; determining a total performance index loss value according to each predicted polyethylene performance index value and a polyethylene performance index demand; generating a new polyethylene polymerization parameter group according to the total performance index loss value; according to the new polyethylene polymerization parameter group, updating the plurality of polyethylene polymerization parameter groups to obtain an updated polyethylene polymerization parameter group; and determining the polyethylene polymerization parameter group with the minimum loss value as a target polyethylene polymerization parameter group. The optimization efficiency of the polyethylene polymerization parameters can be improved.

The invention relates to a preparation method of branched polyethylene and the branched polyethylene obtained by the method. According to the invention, the polyethylene preparation method with two ethylene polymerization steps connected in series is adopted, and different specific catalysts are used in different steps, so that the molecular weight and molecular weight distribution of polyethylene can be regulated and controlled without a complicated catalyst structure and harsh reaction conditions; the molecular weight distribution of polyethylene is improved, and the processability of polyethylene is improved.

The application discloses a supported nickel catalyst and a method for catalyzing ethylene polymerization, and belongs to the technical field of ethylene polymerization. The supported nickel catalyst is prepared by mixing and reacting alkyl magnesium, chlorinated alkyl aluminum and a nickel complex shown in formula 1; wherein R and R' are independently selected from C1-C 10 alkyl, C6-C 18 aryl, C6-C 18 heteroaryl, C1-C 30 alkoxy, C2-C 30 alkylamino, C6-C 30 aryloxy, C6-C 30 arlamino, C 10 -C 30 aralkyl, C3-C 30 siloxy, halogen, nitro, one or more of which. The supported nickel catalyst has excellent stability and high catalytic activity, and can be mass-produced and applied. The supported nickel catalyst can be used for catalyzing ethylene polymerization to obtain ultrahigh molecular weight polyethylene which is low in branching degree, narrow in molecular weight distribution, good in mechanical property, easy to process and free of sticky kettle phenomenon.

Metallocene solutions containing trimethylaluminum, a C4-C8 alkane solvent, and a metallocene compound in an amount from 0.2 to 8 mg per mL of the metallocene solution are described. Catalyst compositions incorporating these metallocene solutions plus an activator-support and an organoaluminum compound can be utilized in polymerization processes to produce polyethylene products.

The invention discloses an alkoxy magnesium carrier for olefin polymerization, a preparation method, a catalyst and an olefin polymerization method. The alkoxy magnesium carrier is prepared from the following raw materials: magnesium powder, mixed alcohol, a halogenating agent, a compound A with a structure as shown in a formula (I) and an inert solvent. The alkoxy magnesium carrier, the titanium-containing compound, the internal electron donor compound and the aluminum-containing compound can be used for preparing the Ziegler-Natta catalyst for olefin polymerization. The alkoxy magnesium carrier is excellent in morphology, controllable in particle size and narrow in particle size distribution, the alkoxy magnesium carrier is not prone to breakage when used for preparing an alkoxy magnesium carrier type catalyst for ethylene polymerization, and the prepared catalyst has the advantages of being high in activity, excellent in hydrogen regulation performance and the like.

The invention relates to the technical field of polyolefin catalysts, and particularly discloses a phenoxy imine compound, a preparation method and application thereof, an olefin polymer and a preparation method thereof. The phenoxy imine compound has the following structural formula, in the structural formula, R1 is selected from tertiary butyl, isopropyl, tertiary butyl, cycloalkyl or adamantyl; r2 is selected from cyclopentyl or cyclohexyl; ad is adamantyl; m is selected from Ti or Zr; and X is selected from Cl, Br or-NMe2. The phenoxy imine compound is applied to catalysis of ethylene polymerization and ethylene and alpha-olefin copolymerization reaction, shows high reaction activity, thermal stability and extremely strong regulation and control performance on polyolefin molecular weight, and has wide industrial application prospects.

The present application relates to the field of ethylene modified polyvinyl alcohol preparation, in particular to a method for preparing ethylene modified polyvinyl alcohol. The method comprises: (1) polymerizing ethylene ester monomer and ethylene in the presence of solvent and initiator to obtain a polymerization liquid; (2) sequentially performing alcoholysis treatment and separation treatment on the polymerization liquid to obtain ethylene modified polyvinyl alcohol; wherein the polymerization reaction system used in the polymerization reaction comprises: sequentially connected oxygen removal device and reaction device; the oxygen removal device comprises an oxygen remover tank body, a liquid monomer feeding port and a bubbling gas feeding port arranged at the top of the oxygen remover tank body; the reaction device comprises a reactor tank body, a deoxygenated liquid monomer feeding port and a gas phase monomer feeding port arranged at the top of the reactor tank body, and a heat exchanger arranged in the reactor tank body. The problems of low heat removal efficiency and high safety risk in the polymerization process of ethylene ester monomer and ethylene can be solved.

The present application provides a method for preparing polyethylene wax by using metallocene catalyst, which comprises polymerizing ethylene in the presence of metallocene catalyst to prepare polyethylene wax; the metallocene catalyst comprises metallocene compound and activator selected from alkyl aluminum and / or borate. The polyethylene wax prepared by the method of the present application has a viscosity average molecular weight of 1000-10000 and a molecular weight distribution of 1.5-3; the polyethylene wax has a relatively narrow molecular weight distribution, and the preparation method is simple and economical, and has a good industrial application prospect.

The utility model provides a tower type reaction system for producing PAO or POE through ethylene polymerization. The reaction system comprises a tower type reactor, wherein a baffling assembly and a strengthening unit are sequentially arranged in the tower type reactor, the baffling assembly comprises a plurality of arc-shaped baffle plates and buckles used for fixedly connecting the arc-shaped baffle plates with the tower type reactor, and the arc-shaped baffle plates are distributed in the tower type reactor in a staggered manner; the distance between the arc-shaped baffle plate positioned at the bottom in the plurality of arc-shaped baffle plates and the strengthening unit is 0.8-1.2 times of the tower diameter of the tower reactor; the top of the tower reactor is also provided with a product outlet, the bottom of the tower reactor is provided with a feed port and a circulating feed port, the bottom of the tower reactor is also provided with a circulating discharge port, and the feed port and the circulating feed port are both communicated into the strengthening unit. According to the utility model, the polymerization degree of polymerization reaction is controlled by using the tower type reactor and the arc-shaped baffle plate.

This invention discloses a phenyl-modified, biasymmetric (α-diimine) nickel olefin catalyst based on acenaphthoquinone as its framework, its preparation method, and its applications. The catalyst's structural formula is shown in Formula (I), where X is chlorine or bromine. The catalyst has a simple preparation process and, when used as a co-catalyst for ethylene polymerization, exhibits results contrary to conventional experimental observations: larger substituents lead to lower molecular weight, better flowability, and dispersibility in the polymerized product, showing broad application prospects in the elastomer field. Furthermore, this type of catalyst also exhibits good thermal stability and polymerization activity, demonstrating promising industrial application prospects. Formula (I).

The invention discloses a method and a system for optimizing a stirring flow field of a vinyl chloride polymerization reaction kettle, and relates to the technical field of vinyl chloride polymerization production optimization. Comprising the following steps: collecting physical attribute parameters of a reaction kettle structure, a stirring assembly and a medium, and inputting the parameters into a chloroethylene polymerization flow field CFD simulation platform; constructing a turbulence multiphase polymerization viscosity coupling model to associate viscosity and turbulence intensity, constructing a stirring flow field heat and mass transfer association model to describe stirring parameters and a heat and mass transfer rule, and introducing a multiphase flow interface tracking optimization algorithm to capture three-phase interface evolution; and collaboratively inputting the model and algorithm output data into a platform for multi-physics field coupling simulation, adjusting parameters for repeated simulation, and comparing flow field uniformity with heat and mass transfer efficiency data to determine optimal parameters. The system is matched with the method, and collaborative operation of parameter collection, model construction, simulation calculation and parameter optimization is achieved. The flow field simulation precision and the parameter optimization systematicness are improved, and the polymerization reaction stability and the product quality are guaranteed.

The application provides a macromolecular alpha-diimine nickel and palladium catalyst, and a preparation method and application thereof.The macromolecular alpha-diimine nickel and palladium catalyst provided by the application has a structure shown in formula I or II, contains a double bond on a skeleton, and is special in structure; when the catalyst is used to catalyze ethylene polymerization, it is found that the catalytic activity is high, and can reach 2.5*10 7 g mol ‑1 h ‑1 Above; and the molecular weight and the branching degree of the prepared polymer can be greatly adjusted, and branched polyolefin with a molecular weight of 0.3-38.0*103 and a branching degree of 48-111 / 1000C can be prepared.

The Ziegler-Natta catalyst for ethylene polymerization includes not only a Ziegler-Natta main catalyst for ethylene polymerization including an internal electron donor satisfying a specific formula, but also at least one external electron donor satisfying a specific formula to increase the number of active sites of a titanium compound, the polyethylene prepared thereby using the Ziegler-Natta catalyst for ethylene polymerization has a high MFR ratio and thus has good processability, thereby ensuring an improvement in polyethylene resin productivity.

The invention discloses a method for producing a low-entanglement UHMWPE supported Ziegler-Natta catalyst and the catalyst, and relates to the technical field of catalyst production, and the method comprises the following steps: S1, preparing a carrier macroporous SiO2; s2, preparing a supported catalyst; s3, ethylene polymerization; aiming at the problem of product entanglement of a Ziegler-Natta catalyst, a silica gel supported catalyst using large-aperture SiO2 as a carrier is developed, the carrier has an extremely high pore size, uniform distribution of MgCl2 on the SiO2 carrier can still be realized under a relatively high MgCl2 loading capacity, Ti active sites are fixed by the highly distributed MgCl2 through Mg-Cl-Ti chemical bonds, and the activity of the catalyst is improved. And the dispersion degree of Ti is improved through uniformly distributed MgCl2, so that the adjacent entanglement phenomenon is reduced, and the preparation of the low-entanglement UHMWPE under the industrial polymerization condition is realized.

The invention belongs to the technical field of chemical catalysis, and provides a preparation method and application of a modified MCM-22 molecular sieve catalyst. Unroasted MCM-22 (P) is used as a raw material, organic alkali (such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide or tetrabutylammonium hydroxide) is adopted for modification treatment, and then ion exchange and roasting are performed to obtain the hydrogen type modified molecular sieve. Organic alkali has the synergistic effect of alkali treatment and structure guiding, and the crystal phase purity and framework integrity are maintained while controllable desilicication is achieved. The catalyst is used for alkylation removal reaction of thiophenic sulfur in styrene, the selectivity of mono-substituted alkylation products is remarkably improved, and side reaction of styrene polymerization is effectively inhibited. The preparation method is simple, the catalytic performance is excellent, and the catalyst has a good industrial application prospect.

The invention discloses a high-strength tarpaulin and a preparation method thereof, and aims to solve the problems that the tensile strength and tear strength of the traditional tarpaulin are difficult to meet the requirements in a high-strength application scene, and in addition, the binding force between a coating and base cloth is relatively weak due to the fact that a simple direct coating mode is mostly adopted in a compounding process of the traditional tarpaulin. According to the technical scheme, the preparation method of the high-strength tarpaulin is characterized by comprising the following steps of bottom layer fiber preparation, base cloth spinning, base cloth surface treatment, coating raw material preparation, tarpaulin coating coating and ethylene polymerization to form ultra-high molecular weight polyethylene fibers with the high-strength characteristic, and the bottom layer fibers are endowed with excellent tensile strength and tearing strength; meanwhile, the base cloth is blended with the polyester fibers according to a reasonable volume ratio, the roughness of the surface of the base cloth is increased, the TPU, the nano silicon dioxide and the glass beads are coordinated and matched, the internal structure of the coating is optimized, the comprehensive performance of the coating is improved, and the tarpaulin can keep good use performance in various severe environments.

The invention belongs to the technical field of ethylene polymerization, and particularly relates to a method for selectively preparing 1-octene and 1-hexene from ethylene. The method comprises the following steps: in the presence of a catalyst composition, mixing ethylene with a solvent, and carrying out polymerization reaction and quenching to obtain a product containing 1-octene and 1-hexene, the temperature of the polymerization reaction is 90-110 DEG C; the catalyst composition comprises a compound as shown in a formula I; r < 1 > to R < 4 > are respectively and independently selected from hydrogen, C1-C6 alkyl and C7-C20 aryl substituted alkyl; x is halogen; m is metal chromium; according to the compound shown in the formula I, efficient preparation of 1-octene and 1-hexene is guaranteed at the specific temperature, polymer wall hanging and blocking are reduced, a device can stably operate for a long time, and good selectivity of 1-octene and 1-hexene is kept for a long time.

The invention relates to the field of catalytic polymerization of olefins, in particular to a flexible amino imine nickel-based catalyst and a preparation method and application thereof, the flexible amino imine nickel-based catalyst has a structure as shown in a formula I or a formula II, and R1 and R2 are respectively and independently selected from at least one of cyclopentyl and cyclohexyl. According to the flexible amino imine nickel-based catalyst, two kinds of amino imine serve as a framework of the catalyst, two kinds of flexible naphthenic bases are introduced to the axial positions of the catalyst respectively, and the performance of the catalyst is remarkably affected by the ligand framework structure and the naphthenic base ring size; and cyclohexyl and butyl skeletons with larger volumes are beneficial to generation of products with higher molecular weights. Compared with the traditional alpha-diimine nickel catalyst, the alpha-amino imine nickel catalyst shows that the polyethylene wax generated by the alpha-amino imine nickel catalyst has higher melting point and lower molecular weight. The catalyst has good potential application value in the ethylene polymerization preparation industry.

The present application relates to a kind of supported post-transition metal catalyst for ethylene polymerization and in situ grafting and its preparation method and application.The supported post-transition metal catalyst includes the blending component and / or reaction product of the following raw materials: carrier, post-transition metal catalyst, activator and radical initiator, and the activator is organic aluminum compound.In the loading process, radical initiator is added, and the supported post-transition metal catalyst particles are formed by spray drying, the particle size is adjustable, the particle shape is good, the particle size distribution is narrower, it is easier to control, so as to prepare smaller polyethylene particles, and then it is beneficial to improve the grafting reaction rate.The catalyst and polymerization method can directly obtain grafted polyethylene by one-step method, and do not need drying and separation, simplify the preparation process of grafted polyethylene, the amount of initiator and polar monomer is less, grafting reaction is more uniform, grafting rate is higher, and side reaction is less.Powder has good particle morphology, and the bulk density is high.

The invention relates to the technical field of catalysts for preparing olefin polymers, and discloses a catalyst, a preparation method thereof and an application of the catalyst in an ethylene polymerization reaction, a carrier is a clay sepiolite mesoporous material carrier, active components are a magnesium component and a titanium component, the average particle diameter of the carrier is 20-50 microns, and the average particle diameter of the carrier is 20-50 microns. The specific surface area is 150-600 m < 2 > / g, the pore volume is 0.5-1.5 ml / g, and the most probable pore diameters are 2-4 nm, 5-15 nm and 10-40 nm respectively. The catalyst has high catalytic activity when being used for ethylene homopolymerization or copolymerization, the bulk density of the prepared polymer is high, the melt flow ratio of the prepared polymer is small, and the molecular weight distribution of the reflected polymer is narrow.

The invention provides a remote large-steric-hindrance substituted phenanthroline framework iron complex and a ligand compound thereof, a catalyst composition containing the complex and application of the complex to catalysis of ethylene oligomerization and polymerization reactions, and the complex shows excellent catalytic activity and thermal stability in catalysis of ethylene oligomerization and polymerization reactions. The catalytic performance of the iron complexes is obviously superior to that of similar iron complexes with other phenanthroline frameworks.