The invention relates to a purification method for purifying a vinylidene fluoride polymer comprising at least one impurity, the method comprising the following steps: washing of the vinylidene fluoride polymer with a stream of supercritical fluid; and extraction of residual supercritical fluid from the vinylidene fluoride polymer.

The invention also relates to a vinylidene fluoride polymer, a fluid conveyance part comprising or consisting of said polymer; as well as the use of said fluid conveyance part.

The present invention discloses methods for removing volatile components from an ethylene polymer effluent stream from a polymerization reactor, and related polyethylene recovery and volatile removal systems. In these methods and systems, the polymer solids temperature is increased significantly prior to introduction of the polymer solids into a purge column for the final stripping of volatile components from the polymer solids.

The present invention discloses methods for removing volatile components from an ethylene polymer effluent stream from a polymerization reactor, and related polyethylene recovery and volatile removal systems. In these methods and systems, the polymer solids temperature is increased significantly prior to introduction of the polymer solids into a purge column for the final stripping of volatile components from the polymer solids.

Provided is a method for producing a latex comprising hollow resin particles each with a high void ratio and a method for producing hollow resin particles each with a higher void ratio. In the method for producing the latex: a suspension treatment of the mixture liquid which comprises a monomer, a crosslinkable monomer, an oil-soluble polymerization initiator, a fat/fatty oil, a hydrocarbon solvent, a suspension stabilizer and an aqueous medium is carried out to prepare a suspension comprising monomer drops; a polymerization reaction of the suspension is carried out to prepare a precursor composition which comprises precursor particles each having a hollow portion including the hydrocarbon solvent.

Provided is a method for producing a latex comprising hollow resin particles each with a high void ratio and a method for producing hollow resin particles each with a higher void ratio. In the method for producing the latex: a suspension treatment of the mixture liquid which comprises a monomer, a crosslinkable monomer, an oil-soluble polymerization initiator, a fat/fatty oil, a hydrocarbon solvent, a suspension stabilizer and an aqueous medium is carried out to prepare a suspension comprising monomer drops; a polymerization reaction of the suspension is carried out to prepare a precursor composition which comprises precursor particles each having a hollow portion including the hydrocarbon solvent.

The present invention relates to a copolymer including 20 to 65 wt % of units derived from an alkyl styrene-based monomer; 10 to 40 wt % of units derived from a (meth)acrylate-based monomer; and 20 to 40 wt % of units derived from vinyl cyan-based monomer, based on the total weight of the copolymer, wherein the residual monomer content is 780 ppm or less, and a method for preparing the same.

The present invention relates to a copolymer including 20 to 65 wt % of units derived from an alkyl styrene-based monomer; 10 to 40 wt % of units derived from a (meth)acrylate-based monomer; and 20 to 40 wt % of units derived from vinyl cyan-based monomer, based on the total weight of the copolymer, wherein the residual monomer content is 780 ppm or less, and a method for preparing the same.

A process comprising polymerizing olefin monomers and optionally comonomers in a first reactor vessel, thereby forming a raw product stream comprising polymerized solids, unreacted monomer and optionally comonomer, the polymerized solids comprising olefin polymer, volatile organic compounds (VOC) and catalyst system. Then the polymerized solids are contacted with a catalyst poison selected from carbon monoxide, carbon dioxide, oxygen, water, alcohols, amines, or mixtures thereof, thereby forming a passivated stream. The passivated stream is maintained in an agitated state within a second reactor. The passivated stream within the second reactor is then contacted with a circulating gas comprising unreacted monomer for a residence time, thereby reducing the concentration of VOC in the polymerized solids by at least 10 wt % compared to the level before entering the second reactor, thereby forming a purified olefin polymer solids stream.

A process comprising polymerizing olefin monomers and optionally comonomers in a first reactor vessel, thereby forming a raw product stream comprising polymerized solids, unreacted monomer and optionally comonomer, the polymerized solids comprising olefin polymer, volatile organic compounds (VOC) and catalyst system. Then the polymerized solids are contacted with a catalyst poison selected from carbon monoxide, carbon dioxide, oxygen, water, alcohols, amines, or mixtures thereof, thereby forming a passivated stream. The passivated stream is maintained in an agitated state within a second reactor. The passivated stream within the second reactor is then contacted with a circulating gas comprising unreacted monomer for a residence time, thereby reducing the concentration of VOC in the polymerized solids by at least 10 wt % compared to the level before entering the second reactor, thereby forming a purified olefin polymer solids stream.

Systems and methods for improved degassing of polymer flake are provided herein. These systems include a polymerization reactor configured to polymerize one or more olefin monomers and produce a product stream comprising solid polymer flake entrained in a fluid; a flash chamber configured to separate the solid polymer flake from the fluid and to produce a fluid stream and a concentrated stream; and a first degassing chamber configured to separate the concentrated stream by contacting the concentrated stream with a purge fluid comprising one or more light hydrocarbons to produce a partially degassed polymer flake stream and a purge fluid stream.