Abstract: The invention provides a continuous preparation method of 2,3,3,3-tetrafluoropropene, comprising the following steps: carrying out liquid-phase catalytic telomerization reaction on ethylene and carbon tetrachloride serving as initial raw materials in the presence of a composite catalyst to obtain a reaction product; performing two-stage membrane separation and purification on the reaction product, and then sequentially performing a primary high-temperature cracking reaction, a gas-phase chlorination reaction, a secondary high-temperature cracking reaction, a primary gas-phase catalytic fluorination reaction and a secondary gas-phase catalytic fluorination reaction to obtain a reaction product; condensing and rectifying the secondary gas-phase catalytic fluorination reaction product to obtain the 2,3,3,3-tetrafluoropropene product.

Abstract: Disclosed are a copolymerized PVDF resin for lithium battery binders and its preparation method. 300 to 600 parts of deionized water, 0.04 to 0.25 part of a pH buffer regulator, 85 to 99.5 parts of a vinylidene fluoride (VDF) monomer, 0.5 to 15 parts of a comonomer, 0.3 to 3 parts of a metallocene synergist, 0.2 to 1.0 part of an initiator, 0.08 to 0.35 part of a dispersant react at 40 to 65° C., 5.5-8.0 Mpa. At the end of the reaction, the unreacted monomers are recovered, and then the operations of washing, filtering, and drying are carried out to obtain the copolymerized PVDF resin. For the copolymerized PVDF resin for lithium battery binders, the binding of PVDF resin to a positive electrode active material and current collector is improved, and the rotational viscosity of the NMP solution and the preparation and dispersion requirements for PVDF resin slurry are reduced.

Abstract: The invention provides a continuous preparation method of 2,3,3,3-tetrafluoropropene, comprising the following steps: carrying out liquid-phase catalytic telomerization reaction on ethylene and carbon tetrachloride serving as initial raw materials in the presence of a composite catalyst to obtain a reaction product; performing two-stage membrane separation and purification on the reaction product, and then sequentially performing a primary high-temperature cracking reaction, a gas-phase chlorination reaction, a secondary high-temperature cracking reaction, a primary gas-phase catalytic fluorination reaction and a secondary gas-phase catalytic fluorination reaction to obtain a reaction product; condensing and rectifying the secondary gas-phase catalytic fluorination reaction product to obtain the 2,3,3,3-tetrafluoropropene product.