Disclosed are a heat-expandable polyvinylidene chloride microsphere and its preparation method. The preparation method comprises: by weight, dissolving 250 to 550 parts of an aqueous-phase polymerization inhibitor, 20 to 100 parts of a dispersant, and 3 to 15 parts of a co-dispersing monomer in deionized water, adjusting a pH value of the solution and cooling the solution to obtain an aqueous phase for later use; dissolving 5 to 15 parts of a cross-linking agent and 20 to 45 parts of an initiator in 1000 to 2000 parts of a mixed monomer, and cooling the solution to obtain an oil phase for later use; mixing and homogenizing the aqueous phase and the oil phase with stirring to obtain a homogenized mixed solution; adding 300 to 550 parts of a foaming agent to the homogenized mixed solution and homogenizing the resulting solution with stirring to obtain a homogenized mixed solution containing the foaming agent; reacting the homogenized mixed solution containing the foaming agent with stirring; at the end of the reaction, cooling to room temperature, filtering the resulting suspension to obtain filtrate, centrifuging and dehydrating the filtrate, and drying to obtain the heat-expandable polyvinylidene chloride microsphere product. This disclosure has the advantages of simple process and environmental friendliness, and the obtained product has good performance.

The present invention relates to a method for producing a carbon fiber. In the method for producing the carbon fiber, a high pure acrylonitrile monomer with specific contents of impurities and a comonomer are used to produce an acrylonitrile copolymer, and the acrylonitrile copolymer is subjected to a spinning operation, a stretching operation, an oxidation treatment and a carbonization treatment in sequence, for obtaining the carbon fiber. The acrylonitrile copolymer with an appropriate falling-ball viscosity and an appropriate weight-average molecular weight is beneficial to the spinning operation, thereby reducing an inner pore diameter and enhancing strength of the resulted carbon fiber.

The present invention relates to a method for producing a carbon fiber. In the method for producing the carbon fiber, a high pure acrylonitrile monomer with specific contents of impurities and a comonomer are used to produce an acrylonitrile copolymer, and the acrylonitrile copolymer is subjected to a spinning operation, a stretching operation, an oxidation treatment and a carbonization treatment in sequence, for obtaining the carbon fiber. The acrylonitrile copolymer with an appropriate falling-ball viscosity and an appropriate weight-average molecular weight is beneficial to the spinning operation, thereby reducing an inner pore diameter and enhancing strength of the resulted carbon fiber.

The invention relates to an acrylonitrile copolymer binder and application thereof in lithium ion battery, belonging to the field of lithium ion battery. The technical problem to be solved by the invention is to provide an acrylonitrile copolymer binder comprising the following structural units in percentage by weight: 78-95% of acrylonitrile unit, 1-10% of acrylic ester unit and 2-15% of acrylamide unit. For the binder of the invention, acrylonitrile monomer is taken as the main body, and acrylic ester monomer, acrylamide monomer or acrylate salt monomer with strong polarity is added to acrylonitrile for copolymerization to enable the flexibility of a polymer membrane, the affinity of an electrolyte and the proper swelling degree in the electrolyte while keeping strong adhesion or intermolecular force of acrylonitrile polymer molecules, so as to fit the periodic volume changes of electrode active materials along with lithium ion intercalation/deintercalation in charging and discharging processes, thereby improving the energy density and cycle performance of the lithium ion battery.

The invention relates to an acrylonitrile copolymer binder and application thereof in lithium ion battery, belonging to the field of lithium ion battery. The technical problem to be solved by the invention is to provide an acrylonitrile copolymer binder comprising the following structural units in percentage by weight: 78-95% of acrylonitrile unit, 1-10% of acrylic ester unit and 2-15% of acrylamide unit. For the binder of the invention, acrylonitrile monomer is taken as the main body, and acrylic ester monomer, acrylamide monomer or acrylate salt monomer with strong polarity is added to acrylonitrile for copolymerization to enable the flexibility of a polymer membrane, the affinity of an electrolyte and the proper swelling degree in the electrolyte while keeping strong adhesion or intermolecular force of acrylonitrile polymer molecules, so as to fit the periodic volume changes of electrode active materials along with lithium ion intercalation/deintercalation in charging and discharging processes, thereby improving the energy density and cycle performance of the lithium ion battery.

Free-standing non-fouling polymers and polymeric compositions, monomers and macromonomers for making the polymers and polymeric compositions, objects made from the polymers and polymeric compositions, and methods for making and using the polymers and polymeric compositions

Free-standing non-fouling polymers and polymeric compositions, monomers and macromonomers for making the polymers and polymeric compositions, objects made from the polymers and polymeric compositions, and methods for making and using the polymers and polymeric compositions

Free-standing non-fouling polymers and polymeric compositions, monomers and macromonomers for making the polymers and polymeric compositions, objects made from the polymers and polymeric compositions, and methods for making and using the polymers and polymeric compositions

A method for manufacturing a powdery paper-strengthening agent including a branched (meth)acrylamide-based polymer (A) which includes a step of obtaining (A) component by polymerizing (meth)acrylamide (a1), anionic vinyl monomer (a2), cationic vinyl monomer (a3) and crosslinkable vinyl monomer (a4) in a solvent in a presence of a polymerization initiator, a step of dropping or putting the above (A) component into an organic solvent to form a precipitate, and a step of drying and pulverizing (A) component obtained as the precipitate.

Provided is an aqueous binder composition for a secondary battery electrode, comprising a copolymer and a dispersion medium, wherein the copolymer comprises a structural unit (a) derived from a carboxylic acid group-containing monomer, a structural unit (b) derived from an amide group-containing monomer, a structural unit (c) derived from a nitrile group-containing monomer, and at least one anionic reactive emulsifier, with an improved binding capability. In addition, battery cells comprising the cathode prepared using the binder composition disclosed herein exhibits exceptional electrochemical performance.