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 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.

A process for reducing the amount of residual monomer in aqueous polymerization emulsion by using a sequential polymerization steps, The first step consists in adding an emulsion, of vinyl ester of alkyl of C1 to C18 carboxylic acids, to water containing a radical initiator, the second step consists in adding further an emulsion of alkyl acrylate and/or methacrylate, and the third step consists in c) adding to polymeric emulsion, resulting of the steps a) and b), pure liquid acrylate or methacrylate with alkyl chain of C.sub.1 to C.sub.12.

A process for reducing the amount of residual monomer in aqueous polymerization emulsion by using a sequential polymerization steps, The first step consists in adding an emulsion, of vinyl ester of alkyl of C1 to C18 carboxylic acids, to water containing a radical initiator, the second step consists in adding further an emulsion of alkyl acrylate and/or methacrylate, and the third step consists in c) adding to polymeric emulsion, resulting of the steps a) and b), pure liquid acrylate or methacrylate with alkyl chain of C.sub.1 to C.sub.12.

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.

Methods according to the present invention decolorize a polymer by mixing a solution of the polymer with a photocatalyst and exposing the mixture to ultraviolet light; by way of non-limiting example, the polymer may be a star polymer and the photocatalyst may be titanium dioxide. Methods according to the present invention also utilize a metal scavenger, in some embodiments a solid-phase metal scavenger, to remove a metal catalyst from a polymer solution; by way of non-limiting example, the metal catalyst may be a tin catalyst. The decolorization methods and the catalyst removal methods of the present invention may be practiced separately, sequentially in any order, or simultaneously.

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.

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.