Provided is a method of preparing a polymer including: supplying a monomer stream and a solvent stream to a reactor and performing a polymerization reaction to prepare reaction product; supplying a reactor discharge stream to a separation device, separating a gaseous stream including an inert gas in the separation device, and supplying a liquid stream including the reaction product from which the inert gas is removed to a volatilization device; separating a polymer from a lower discharge stream from the volatilization device and supplying an upper discharge stream including an unreacted monomer, a solvent, and an inert gas to a condensation unit; and condensing and separating the unreacted monomer and the solvent in the condensation unit and supplying a gaseous stream to a vacuum unit.

A high pressure polymerization to form an ethylene-based polymer, the process comprising the following: polymerizing a reaction mixture comprising ethylene, using a reactor system comprising at least three ethylene-based feed streams and a reactor configuration that comprises at least four reaction zones.

A high pressure polymerization, as described herein, to form an ethylene-based polymer, comprising the following steps: polymerizing a reaction mixture comprising ethylene, using a reactor system comprising at least three ethylene-based feed streams and a reactor configuration that comprises at least four reaction zones, and at least one of the following a) through c), is met: (a) up to 100 wt % of the ethylene stream to the first zone comes from a high pressure recycle, and/or up to 100 wt % of the last ethylene stream to a zone comes from the output from a Primary compressor system; and/or (b) up to 100 wt % of the ethylene stream to first zone comes from the output from a Primary compressor system, and/or up to 100 wt % of the last ethylene stream to a zone comes from a high pressure recycle; and/or (c) the ethylene stream to the first zone, and/or the last ethylene stream to a zone, each comprises a controlled composition; and wherein each ethylene stream to a zone receives an output from two or more cylinders of the last compressor stage of a Hyper compressor system.

A process for reducing the volatile organic compound content of granular plastomers having a density of equal to or lower than 883 kg/m.sup.3 and a MFR.sub.2 of 100.0 g/10 min or lower (ISO 1133 at 2.16 kg load and 190° C.), to below 65 ppm (VOC, VDA277), the process comprising the steps of providing a granular raw plastomer in a treatment vessel, the granular raw plastomer having a density of equal to or lower than 883 kg/m.sup.3, and a MFR.sub.2 of 100.0 g/10 min or lower (ISO 1133 at 2.16 kg load and 190° C.), and a volatile organic compound content (VOC, VDA277) of above 150 ppm, subjecting said granular raw plastomer to a gasflow within the range of 30 m.sup.3/(h t) to 150 m.sup.3/(h t) for an aeration time of less than 96 hours, whereby the gas has a minimum temperature of at least 26° C. measured at a gas inlet of the treatment vessel and a maximum temperature of 4° C. below the Vicat temperature (10 N, ISO 306) of the granular raw plastomer or 35° C. measured at the gas inlet of the treatment vessel, whatever value is lower; and recovering the granular plastomer.

Provided is a method of preparing a graft copolymer, which includes: preparing a liquid maleimide-based monomer; preparing a reaction solution including a diene-based rubber polymer, an aromatic vinyl-based monomer, and a vinyl cyan-based monomer; and adding the liquid maleimide-based monomer and the reaction solution to a reactor and carrying out polymerization. According to the preparation method of the present invention, the amount of the maleimide-based monomer involved in the polymerization can be increased, and the color characteristics, glass transition temperature, and softening temperature of the graft copolymer are improved.

Provided is a method of preparing a graft copolymer, which includes: preparing a liquid maleimide-based monomer; preparing a reaction solution including a diene-based rubber polymer, an aromatic vinyl-based monomer, and a vinyl cyan-based monomer; and adding the liquid maleimide-based monomer and the reaction solution to a reactor and carrying out polymerization. According to the preparation method of the present invention, the amount of the maleimide-based monomer involved in the polymerization can be increased, and the color characteristics, glass transition temperature, and softening temperature of the graft copolymer are improved.

The present invention is directed to a process for separating an olefin copolymer from volatile gases using a flash separator. The flash separator can be used with a solution or high pressure process. The mass transport of volatile gases from the viscous polymer melt is increased.

An eductor, a process and apparatus for gas phase polymerization of olefins in a polymerization reactor are disclosed. The process and apparatus employ an eductor which has an inlet which makes a bend of less than about 90° toward the outlet after entering the mixing chamber of the eductor.

Disclosed are a system for controlling an ethylene vinyl acetate (EVA) copolymerization process and a method of controlling the same. The system for controlling the EVA copolymerization process may include a database for analysis configured to store analysis data obtained by matching processing conditions with measured data for first EVAs produced under the processing conditions, a computer programmed to estimate a VA content with respect to second EVA using the analysis data, a computer programmed to estimate a molecular weight distribution of the second EVA using the VA content estimated in the VA content estimation unit and processing factors corresponding thereto, and a computer programmed to estimate a recovery system blockage phenomenon using the VA content estimated and the molecular weight distribution estimated.

Disclosed are a system for controlling an ethylene vinyl acetate (EVA) copolymerization process and a method of controlling the same. The system for controlling the EVA copolymerization process may include a database for analysis configured to store analysis data obtained by matching processing conditions with measured data for first EVAs produced under the processing conditions, a computer programmed to estimate a VA content with respect to second EVA using the analysis data, a computer programmed to estimate a molecular weight distribution of the second EVA using the VA content estimated in the VA content estimation unit and processing factors corresponding thereto, and a computer programmed to estimate a recovery system blockage phenomenon using the VA content estimated and the molecular weight distribution estimated.