Abstract: A catalyst system for olefin polymerization contains a main catalyst and a cocatalyst. The cocatalyst contains a twelve-membered ring compound represented by formula (M). The catalyst system is suitable for preparing polypropylene products having high stereoregularity and low ash, and can regulate the melt index of the products within a wide range by adjusting the amount of hydrogenation. It is also suitable for copolymerization systems to improve the copolymerization yield.

Abstract: A halogen-containing compound represented by a formula I and a use thereof as a ligand of an ethylene oligomerization catalyst composition, an ethylene oligomerization catalyst composition comprising the halogen-containing compound, and an ethylene oligomerization method, ethylene trimerization method and ethylene tetramerization method using the catalyst composition are provided. Serving as the ligand of the ethylene oligomerization catalyst, the halogen-containing polymer may effectively improve the catalytic performance of a catalyst system, especially by displaying a significantly improved catalytic performance in an ethylene oligomerization reaction. The maximum catalyst activity may exceed 4×108 g·mol(Cr)?1·h?1, and the total selectivity of 1-hexene and 1-octene exceeds 92 wt %. In a C6 product, the content of 1-hexene may reach about 97%, and in a C8 product, the content of 1-octene may reach more than 98%.

Abstract: The present disclosure relates to the technical field of oilfield chemicals, and discloses an acrylamide copolymer, wherein the acrylamide copolymer comprises a structural unit A, a structural unit B and a structural unit C, wherein the structural unit A has a structure shown in Formula (1), the structural unit B has a structure shown in Formula (2), and the structural unit C has a structure shown in Formula (3) and/or Formula (4); wherein R1 is methyl or H, R2 is —OH, —NH2, —COOH or C2-C12 alkyl, n is an integer between 0 and 6, and a, b and c are each independently selected from integers between 0 and 2.

Abstract: A method and system for separating light hydrocarbons are disclosed, wherein the method comprises compression, cooling, absorption, desorption, rectification, cracking, and recycling cracked gas to the compression step.

Abstract: The invention relates to a spider-silk-like polymer fiber in the technical field of chemical bionics, a preparation method therefor and the use thereof. The spider-silk-like polymer fiber comprises a matrix polymer and a particle additive dispersed therein, wherein the particles have an average particle size of 0.1-1000 microns, and the polymer fiber has a spider-silk-like microstructure comprising a fiber body and spaced spindle knot structural units on the fiber body, wherein the spindle knot structural units comprise the particles, and the radial height of the spindle knot structural units is greater than the diameter of the fiber body. The preparation method of the polymer fiber of the invention does not require greatly modifying the existing spinning processes, and the equipment does not need to be changed, the process is simple, and the cost is low.

Abstract: A supported catalyst and preparation method thereof, the catalyst comprising an organic polymer material carrier and Raney alloy particles supported on the organic polymer material carrier, wherein substantially all of the Raney alloy particles are partially embedded in the organic polymer material carrier. The catalyst can be used in hydrogenation, dehydrogenation, amination, dehalogenation or desulfuration reactions.

Abstract: A polyester composition includes a first polyester selected from one or more of aliphatic-aromatic copolyesters, which is a copolymer comprising repeating units A as shown in formula (I) and repeating units B as shown in formula (II), in which m is an integer of 2 to 10 and n is an integer of 2 to 8; p is an integer of 2 to 10; and m, n and p are the same or different from each other. Optionally, the polyester composition has a second polyester. The polyester composition includes at least two polyesters. The polyester composition can be used in shape memory materials, 3D print wires, heat shrinkable sleeves, functional layers, medical limb immobilization braces, heat shrinkable thin films, nonwoven fabrics, elastic fibers, etc.

Abstract: The present invention discloses a Ziegler-Natta catalyst system for olefin polymerization, comprising at least one compound represented by formula (I) as (i) an internal electron donor, (ii) an external electron donor, or (iii) the both, wherein M1, M2, M3, M4, M5, M6, M1?, M2?, M3?, M4?, M5? and M6? are each independently selected from the group consisting of hydrogen, hydroxy, amino, aldehyde group, carboxy, acyl, halogen atoms, —R1 and —OR2, wherein R1 and R2 are each independently a C1-C10 hydrocarbyl, which is unsubstituted or substituted by a substituent selected from the group consisting of hydroxy, amino, aldehyde group, carboxy, acyl, halogen atoms, C1-C10 alkoxy and heteroatoms; and wherein, when among M1-M6 and M1?-M6?, any two adjacent groups on the same phenyl ring are each independently selected from the group consisting of R1 and —OR2, the two adjacent groups may optionally be linked to form a ring, with a proviso that M1, M2, M3, M4, M5, M6, M1?, M2?, M3?, M4?, M5? and M6? are not simultaneous

Abstract: The magnesium alkoxide particle contains the reaction product of the following components: 1) a magnesium powder; 2) a mixed alcohol; 3) a halogenating agent; and 4) a titanate compound. The magnesium alkoxide particle is used for preparing a catalyst for olefin polymerization.

Abstract: Disclosed is a catalyst component for olefin polymerization. The catalyst component comprises magnesium, titanium, halogen and an internal electron donor. The internal electron donor includes an imine compound with a ketone group as shown in Formula I. Disclosed further is a method of preparing the catalyst component, and a catalyst for olefin polymerization containing the catalyst component. When the catalyst is used in olefin polymerization reaction especially propene polymerization reaction, the catalyst has a high activity and a long term activity and good hydrogen response, and the obtained polymer has characteristics of an adjustable isotactic index and a relatively wide molecular weight distribution.

Abstract: A halogen-containing compound as shown in a formula I can be used as a ligand for an ethylene oligomerization catalyst composition. The ethylene oligomerization catalyst composition containing the halogen-containing compound can be used to catalyze ethylene oligomerization, trimerization and tetramerization reactions. As a ligand of a catalyst for ethylene oligomerization, a fluoropolymer can effectively improve the catalytic performance of a catalyst system, and particularly exhibits improved activity and selectivity in an ethylene oligomerization reaction.

Abstract: Disclosed is a composite catalyst, comprising carbon in a continuous phase and Raney alloy particles in a dispersed phase. The Raney alloy particles are dispersed evenly or unevenly in the carbon in a continuous phase, and the carbon in a continuous phase is obtained by carbonizing at least one carbonizable organic substance. The catalyst has good particle strength, high catalytic activity, and good selectivity.

Abstract: A heat transfer tube includes a twisted baffle arranged in an inner wall of the tube. The twisted baffle extends spirally along an axial direction of the heat transfer tube. The twisted baffle is provided with a non-through gap extending along an axial direction of the heat transfer tube from an end to the other end of the twisted baffle. A cracking furnace uses the heat transfer tube. The heat transfer tube and cracking furnace have good heat transfer effects and small pressure loss.

Abstract: Disclosed is a catalyst pre-contact method for the continuous polymerization of an olefin, wherein a primary catalyst, a co-catalyst and, optionally, an external electron donor are mixed and then undergo a pre-contact reaction, with the pre-contact reaction temperature being ?30° C. to 35° C. and adjustable, and the pre-contact reaction time being 0.5 min to 10 min and adjustable, and the pre-contacted catalyst is brought into a catalyst prepolymerization system and then into a catalyst polymerization system, or is directly brought into the catalyst polymerization system. Further disclosed is a catalyst pre-contact device for the continuous polymerization of an olefin, which can adjust the pre-contact time and pre-contact temperature of the catalyst so that the performance of the catalyst achieves a better level according to the process.

Abstract: A polyester composition, includes an aliphatic polyester and an aliphatic-aromatic copolyester. The aliphatic-aromatic copolyester is a copolymer having a repeating unit A and a repeating unit B. The preparation method for the polyester composition includes the steps of mixing all the components having the aliphatic polyester and the aliphatic-aromatic copolyester, and subjecting the resulting mixture to extrusion granulation.

Abstract: A method for preparing a polyolefin resin powder has the steps of a) heat dissolving a polyolefin resin in an organic solvent having a solubility parameter less than or equal to the solubility parameter of the polyolefin resin to obtain a polyolefin resin solution; b) cooling the polyolefin resin solution to precipitate a solid, thereby obtaining a solid-liquid mixture; c) optionally adding an adjuvant to the solid-liquid mixture and mixing; and d) conducting solid-liquid separation and drying to obtain a polyolefin resin powder suitable for selective laser sintering. The difference between the solubility parameters of the organic solvent and of the polyolefin resin is within 0-20% of the solubility parameter of the polyolefin resin. The polyolefin resin powder obtained according to this method has good antioxidant property, good powder flowability, moderate size, smooth surface, suitable bulk density, and suitable dispersibility and particle size distribution.

Abstract: Butyl rubber, a preparation method therefor, and an application thereof, and a composition and rubber product containing the butyl rubber. The butyl rubber comprises a structural unit derived from isobutylene, a structural unit derived from conjugated diene, and a structural unit selectively derived from aryl olefin represented by formula I, at least a part of the conjugated diene being isoprene. Also provided are an automobile tire inner liner, tube and curing bladder made of the butyl rubber. The butyl rubber has good processability and compounding properties, die swell ratio and integrated mechanical properties, and particularly high tear strength. The butyl rubber can effectively reduce power consumption in the processing and compounding process, and the prepared product has good dimensional stability and application performance.

Abstract: The invention relates to a spider-silk-like polymer fiber in the technical field of chemical bionics, a preparation method therefor and the use thereof. The spider-silk-like polymer fiber comprises a matrix polymer and a particle additive dispersed therein, wherein the particles have an average particle size of 0.1-1000 microns, and the polymer fiber has a spider-silk-like microstructure comprising a fiber body and spaced spindle knot structural units on the fiber body, wherein the spindle knot structural units comprise the particles, and the radial height of the spindle knot structural units is greater than the diameter of the fiber body. The preparation method of the polymer fiber of the invention does not require greatly modifying the existing spinning processes, and the equipment does not need to be changed, the process is simple, and the cost is low.

Abstract: A method for preparing an aliphatic polyester resin powder includes the steps of a) heat dissolving a crystalline aliphatic polyester resin in an organic solvent to obtain an aliphatic polyester resin solution; b) cooling the aliphatic polyester resin solution to precipitate a solid, thereby obtaining a solid-liquid mixture; c) optionally adding an adjuvant to the solid-liquid mixture and mixing; and d) conducting solid-liquid separation and drying to obtain an aliphatic polyester resin powder suitable for selective laser sintering. The crystalline aliphatic polyester resin powder obtained has good antioxidant property, good powder flowability, moderate size, smooth surface, suitable bulk density, and suitable dispersibility and particle size distribution. The aliphatic polyester resin powder is particularly suitable for selective laser sintering method.

Abstract: The present invention relates to a polymer/filler/metal composite fiber, including a polymer fiber comprising a metal short fiber and a filler; the metal short fiber is distributed as a dispersed phase within the polymer fiber and distributed in parallel to the axis of the polymer fiber; the filler is dispersed within the polymer fiber and distributed between the metal short fibers; the filler does not melt at the processing temperature of the polymer; said metal is a low melting point metal and selected from at least one of single component metals and metal alloys, and has a melting point which ranges from 20 to 480° C., and, at the same time, which is lower than the processing temperature of the polymer; the metal short fiber and the polymer fiber have a volume ratio of from 0.01:100 to 20:100; the filler and the polymer have a weight ratio of from 0.1:100 to 30:100.