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 disclosure relates to a process and/or method for producing a polymer dispersion by free-radically initiated emulsion polymerization of radically polymerizable ethylenically unsaturated monomers within a polymerization reactor. The polymer dispersion obtained is transferred to a post-treatment reactor and is post-treated therein. The polymer dispersion within the post-treatment reactor is conveyed, simultaneously to the post-treatment, to a circuit for filtration and analysis and is then subsequently fed back into the post-treatment reactor.

The present disclosure relates to a process and/or method for producing a polymer dispersion by free-radically initiated emulsion polymerization of radically polymerizable ethylenically unsaturated monomers within a polymerization reactor. The polymer dispersion obtained is transferred to a post-treatment reactor and is post-treated therein. The polymer dispersion within the post-treatment reactor is conveyed, simultaneously to the post-treatment, to a circuit for filtration and analysis and is then subsequently fed back into the post-treatment reactor.

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.

The invention relates to a synergistically active composition which comprises a mixture of a sulfinic acid or a salt thereof and ascorbic acid or a salt thereof and the use of the composition as reducing agent. The reducing power of the composition of the invention is significantly higher than the reducing power of the single components.

The invention relates to a synergistically active composition which comprises a mixture of a sulfinic acid or a salt thereof and ascorbic acid or a salt thereof and the use of the composition as reducing agent. The reducing power of the composition of the invention is significantly higher than the reducing power of the single components.

The present invention relates to a process for treating a polymeric dispersion prepared by polymerizing at least one or more unsaturated monomers comprising adding to said polymeric dispersion a sufficient amount of one or more organic peroxides selected from the group consisting of peroxydicarbonates, diacyl peroxides and mixtures thereof. The invention also deals with the use of organic peroxides selected from the group consisting of peroxydicarbonates, diacyl peroxides and mixtures thereof to treat a polymeric dispersion prepared by polymerizing at least one or more unsaturated monomers, preferably in order to reduce the amount of volatile organic compounds present in said polymeric dispersion.

The present invention relates to a process for treating a polymeric dispersion prepared by polymerizing at least one or more unsaturated monomers comprising adding to said polymeric dispersion a sufficient amount of one or more organic peroxides selected from the group consisting of peroxydicarbonates, diacyl peroxides and mixtures thereof. The invention also deals with the use of organic peroxides selected from the group consisting of peroxydicarbonates, diacyl peroxides and mixtures thereof to treat a polymeric dispersion prepared by polymerizing at least one or more unsaturated monomers, preferably in order to reduce the amount of volatile organic compounds present in said polymeric dispersion.

A process for forming voided latex particles is improved by combining swelling and polymerization of an outer shell into a single step. The process includes contacting multi-stage emulsion polymer particles comprising a core, at least one intermediate shell, with a swelling agent, and polymerizing an outer shell after said contacting with swelling agent wherein the core and the at least one intermediate shell are contacted with swelling agent in the presence of less than 0.5% monomer based on the weight of the multi-stage emulsion polymer particles, and substantially all of the swelling occurs during polymerization of the outer shell.

A process for forming voided latex particles is improved by combining swelling and polymerization of an outer shell into a single step. The process includes contacting multi-stage emulsion polymer particles comprising a core, at least one intermediate shell, with a swelling agent, and polymerizing an outer shell after said contacting with swelling agent wherein the core and the at least one intermediate shell are contacted with swelling agent in the presence of less than 0.5% monomer based on the weight of the multi-stage emulsion polymer particles, and substantially all of the swelling occurs during polymerization of the outer shell.