Ziegler-Natta (pro)catalyst systems made with an external electron donor compound, methods of synthesis of same, methods of olefin polymerization using same, and polyolefin polymers made thereby. The external electron donor compound is an azaheterocycle.

Ziegler-Natta (pro)catalyst systems made with an external electron donor compound, methods of synthesis of same, methods of olefin polymerization using same, and polyolefin polymers made thereby. The external electron donor compound is an azaheterocycle.

Ziegler-Natta (pro)catalyst systems made with an external electron donor compound, methods of synthesis of same, methods of olefin polymerization using same, and polyolefin polymers made thereby. The external electron donor compound is a (multi-alkoxy)silane.

Ziegler-Natta (pro)catalyst systems made with an external electron donor compound, methods of synthesis of same, methods of olefin polymerization using same, and polyolefin polymers made thereby. The external electron donor compound is a (multi-alkoxy)silane.

A copolymer including ethylene units and units of one or more C.sub.3-10 alpha-olefins. The copolymer has a number average molecular weight of less than 5,000 g/mol, as measured by GPC. The ethylene content of the copolymer is less than 80 mol %. At least 70% of molecules of the copolymer have an unsaturated group, and at least 70% of said unsaturated groups are located in a terminal vinylidene group or a tri-substituted isomer of a terminal vinylidene group. The copolymer has a crossover temperature of −20° C. or lower and/or a certain ethylene run length. Also disclosed are a method for making the copolymer and polyolefins plasticized with 1-40 wt % of the copolymer.

A copolymer including ethylene units and units of one or more C.sub.3-10 alpha-olefins. The copolymer has a number average molecular weight of less than 5,000 g/mol, as measured by GPC. The ethylene content of the copolymer is less than 80 mol %. At least 70% of molecules of the copolymer have an unsaturated group, and at least 70% of said unsaturated groups are located in a terminal vinylidene group or a tri-substituted isomer of a terminal vinylidene group. The copolymer has a crossover temperature of −20° C. or lower and/or a certain ethylene run length. Also disclosed are a method for making the copolymer and polyolefins plasticized with 1-40 wt % of the copolymer.

A magnesium alkoxide catalyst support and the preparation method and use thereof are provided. The method for preparing the magnesium alkoxide catalyst support comprises the following steps: mixing a metallic magnesium, a monohydric alcohol, a halogenating agent and a surfactant at 0° C. to 90° C. under an inert gas atmosphere, and then washing the resultant with an inert solvent to obtain the magnesium alkoxide catalyst support. A magnesium alkoxide catalyst support obtained by the above method is also provided, which can be used to catalyze olefin polymerization. The magnesium alkoxide catalyst support obtained by the above method according to the invention has excellent particle morphology and controllable size, and is suitable for preparing a catalyst for olefin polymerization.

A copolymer including ethylene units and units of one or more C.sub.3-10 alpha-olefins. The copolymer has a number average molecular weight of less than 5,000 g/mol, as measured by GPC. The ethylene unit content of the copolymer is less than 80 mol %. 70 mol % or greater of the copolymer has a carbon-carbon double bond in a terminal monomer unit, and at least 70 mol % of the terminal unsaturation is vinylidene, one or more tri-substituted isomers of the vinylidene or any combination thereof. The copolymer has a crossover temperature of −20° C. or lower and/or a certain average ethylene run length. Also disclosed are a method for making the copolymer and polyolefins plasticized with 1-40 wt. % of the copolymer. The copolymers may low metal (ash) and/or fluorine contents.

Polyolefin powder is transferred from a gas-phase polymerization reactor to a solid-gas separator having a relatively low pressure, while an amount of monomer gas discharged from the gas-phase polymerization reactor is kept low.

A polyolefin production apparatus includes a gas-phase polymerization reactor 10 that polymerizes an olefin monomer to produce polyolefin powder, a solid-gas separator 20, a circulation pipe LC having both ends connected to the solid-gas separator, and provided with a first compressor CP1, a hopper 30, a first powder-conveying pipe L1 connecting the gas-phase polymerization reactor and the hopper, and provided with a first valve V1 halfway, and a second powder-conveying pipe L2 connecting an outlet of the hopper and the circulation pipe, and provided with a second valve V2 halfway.

Polyolefin powder is transferred from a gas-phase polymerization reactor to a solid-gas separator having a relatively low pressure, while an amount of monomer gas discharged from the gas-phase polymerization reactor is kept low.

A polyolefin production apparatus includes a gas-phase polymerization reactor 10 that polymerizes an olefin monomer to produce polyolefin powder, a solid-gas separator 20, a circulation pipe LC having both ends connected to the solid-gas separator, and provided with a first compressor CP1, a hopper 30, a first powder-conveying pipe L1 connecting the gas-phase polymerization reactor and the hopper, and provided with a first valve V1 halfway, and a second powder-conveying pipe L2 connecting an outlet of the hopper and the circulation pipe, and provided with a second valve V2 halfway.