Disclosed is a method of separating an ethylene oligomerization effluent, in which, during the separation and purification of a product obtained through ethylene oligomerization, the temperature of the reaction product is adjusted and used, thus improving energy efficiency.

A process for producing cycloalkenamer-containing compositions involves converting at least one cycloalkene by ring-opening metathetic polymerization to obtain a polyalkenamer-containing product mixture. The product mixture is worked up to remove monomers and oligomers of the cycloalkenes to obtain the polyalkenamer-containing composition by extraction with CO.sub.2. The extraction involves at least two stages: an extraction with liquid CO.sub.2 under the supercritical conditions, and then an extraction with supercritical CO.sub.2. Such cycloalkenamer-containing compositions can be used, for example, in the field of packaging materials, especially for food and drink.

A process for producing cycloalkenamer-containing compositions involves converting at least one cycloalkene by ring-opening metathetic polymerization to obtain a polyalkenamer-containing product mixture. The product mixture is worked up to remove monomers and oligomers of the cycloalkenes to obtain the polyalkenamer-containing composition by extraction with CO.sub.2. The extraction involves at least two stages: an extraction with liquid CO.sub.2 under the supercritical conditions, and then an extraction with supercritical CO.sub.2. Such cycloalkenamer-containing compositions can be used, for example, in the field of packaging materials, especially for food and drink.

This disclosure relates to a process for polymerization, and in particular to minimizing undesired polymerization reactions downstream of a polymerization reaction zone, for instance by use of a quenching agent that enables fast reaction rates with active polymerization catalyst in the polymerization effluent, so as to quench the catalyst quickly, thereby preventing uncontrolled polymerization reactions. A preferred quenching agent is methanol. Also provided are means for treating polymer recycle streams containing oxygenates, which may result from the use of such quench agents, particularly in polymerization processes including polyene (e.g., diene) monomers.

This disclosure relates to a process for polymerization, and in particular to minimizing undesired polymerization reactions downstream of a polymerization reaction zone, for instance by use of a quenching agent that enables fast reaction rates with active polymerization catalyst in the polymerization effluent, so as to quench the catalyst quickly, thereby preventing uncontrolled polymerization reactions. A preferred quenching agent is methanol. Also provided are means for treating polymer recycle streams containing oxygenates, which may result from the use of such quench agents, particularly in polymerization processes including polyene (e.g., diene) monomers.

A gas phase polymerization assembly comprising a gas phase polymerization reactor having at least one inlet and at least one outlet, a circulation gas compression unit having an inlet and an outlet, whereby the inlet of the circulation gas compression unit is fluidly connected to the at least one outlet of the gas phase polymerization reactor by an unreacted gas line; a flush gas compression unit having an inlet and an outlet, wherein the inlet of the flush gas compression unit is fluidly connected to the outlet of the circulation gas compression unit by a pressurized unreacted gas line; a circulation line fluidly connecting the pressurized unreacted gas line with the at least one inlet of the gas phase polymerization reactor; a flush gas withdrawal line connected to the outlet of the flush gas compression unit.

A gas phase polymerization assembly comprising a gas phase polymerization reactor having at least one inlet and at least one outlet, a circulation gas compression unit having an inlet and an outlet, whereby the inlet of the circulation gas compression unit is fluidly connected to the at least one outlet of the gas phase polymerization reactor by an unreacted gas line; a flush gas compression unit having an inlet and an outlet, wherein the inlet of the flush gas compression unit is fluidly connected to the outlet of the circulation gas compression unit by a pressurized unreacted gas line; a circulation line fluidly connecting the pressurized unreacted gas line with the at least one inlet of the gas phase polymerization reactor; a flush gas withdrawal line connected to the outlet of the flush gas compression unit.

A method for producing a (meth)acrylic resin composition, the method comprising continuously feeding a polymerizable monomer component comprising 50 to 100% by mass of methyl methacrylate, 0 to 20% by mass of an acrylic acid alkyl ester and 0 to 30% by mass of an additional monomer, a chain transfer agent, and a radical polymerization initiator to a tank reactor; conducting bulk polymerization of the polymerizable monomer component at a polymerization conversion ratio of 40 to 70% by mass to obtain a liquid containing a (meth)acrylic resin; continuously feeding the liquid to a vented extruder to separate a volatile component from the (meth)acrylic resin; continuously feeding the separated volatile component to a distillation column to obtain a fraction containing methyl methacrylate; adding a polymerization inhibitor to the fraction; and reusing the fraction which contains the polymerization inhibitor as part of the polymerizable monomer component.

A method including operating a high impact polystyrene (HIPS) reaction system having a devolatilizer downstream of a polymerization reactor, and from which a HIPS product is obtained, and injecting an antioxidant into the HIPS reaction system prior to the devolatilizer, with the antioxidant being one or more aromatic antioxidants. A HIPS product produced by operating a HIPS reaction system to produce a HIPS product, with the HIPS reaction system including a devolatilizer downstream of a polymerization reactor, and including injecting an antioxidant into the HIPS reaction system prior to the devolatilizer, with the antioxidant being comprising one or more aromatic antioxidants. The antioxidant may comprise at least one thiol group, at least one cresol group, or both. A system for producing the HIPS product is also provided.

A method including operating a high impact polystyrene (HIPS) reaction system having a devolatilizer downstream of a polymerization reactor, and from which a HIPS product is obtained, and injecting an antioxidant into the HIPS reaction system prior to the devolatilizer, with the antioxidant being one or more aromatic antioxidants. A HIPS product produced by operating a HIPS reaction system to produce a HIPS product, with the HIPS reaction system including a devolatilizer downstream of a polymerization reactor, and including injecting an antioxidant into the HIPS reaction system prior to the devolatilizer, with the antioxidant being comprising one or more aromatic antioxidants. The antioxidant may comprise at least one thiol group, at least one cresol group, or both. A system for producing the HIPS product is also provided.