The present invention provides a post-treatment method of a vinyl chloride-based polymer including: (a) preparing a stream containing vinyl chloride-based polymer powder and unreacted vinyl chloride-based monomers by drying a vinyl chloride-based polymer latex in a drying unit; (b) filtering the stream containing the vinyl chloride-based polymer powder and the unreacted vinyl chloride-based monomers in a filtering unit; and (c) recirculating a gas containing the unreacted vinyl chloride-based monomers discharged from the filtering unit to a latex storage unit.

Disclosed herein is a system for solution polymerization comprising a reactor system that is operative to receive a monomer and to react the monomer to form a polymer; a plurality of devolatilization vessels located downstream of the reactor system, where each devolatilization vessel operates at a lower pressure than the preceding devolatilization vessel; and a heat exchanger disposed between two devolatilization vessels and in fluid communication with them, where the heat exchanger has an inlet port temperature of 100° C. to 230° C., an outlet port temperature of 200° C. to 300° C., an inlet port pressure of 35 to 250 kgf/cm.sup.2 and an outlet port pressure of 20 to 200 kgf/cm.sup.2; and wherein the polymer solution remains in a single phase during its residence in the heat exchanger.

The present invention relates to an olefinic monomer recovery device capable of suppressing fouling and pressure drop in the recovery device in a process of separating and recovering unreacted monomers after production of a polyolefin resin. The olefinic monomer recovery device is used for separating and recovering unreacted olefinic monomers after production of a polyolefin resin, the apparatus comprising a vertical-type heat exchange unit, and a knock-out drum unit.

The present invention relates to an olefinic monomer recovery device capable of suppressing fouling and pressure drop in the recovery device in a process of separating and recovering unreacted monomers after production of a polyolefin resin. The olefinic monomer recovery device is used for separating and recovering unreacted olefinic monomers after production of a polyolefin resin, the apparatus comprising a vertical-type heat exchange unit, and a knock-out drum unit.

The present invention relates to a process for reducing the volatile organic compound (VOC) content of plastomers the process comprising the steps of subjecting the plastomer in granular form containing VOCs which is contained in an aeration vessel to a gasflow, and withdrawing granular plastomer from the aeration vessel which has a lower content of VOCs, wherein the average particle size of the granular plastomer is greater than 2.5 mm, preferably greater than 2.7 mm, more preferably greater than 3.0 mm, wherein the gas has a minimum temperature of at least 26° C. measured at a gas inlet of the aeration vessel, and a maximum temperature of 4° C. below the Vicat temperature (10N, ISO 306) of the granular plastomer or 35° C. measured at the gas inlet of the aeration vessel, whatever value is lower, and wherein at least a part of the withdrawn granular plastomer is recirculated to the aeration vessel.

Process for producing aqueous polyacrylamide solutions by polymerizing an aqueous solution comprising at least acrylamide thereby obtaining an aqueous polyacrylamide gel and dissolving said aqueous polyacrylamide gel in water, wherein the process is carried out in a modular, relocatable plant. The plant preferably is deployed at a location at which aqueous polyacrylamide solutions are used, for example on an oilfield or in a mining area.

An acrylic rubber, including: 50 to 99.9% by weight of a bond unit derived from at least one (meth) acrylic acid ester selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester; 0.1 to 20% by weight of a bond unit derived from a monomer containing a reactive group; and 0 to 30% by weight of a bond unit derived from other monomer, wherein the acrylic rubber contains a phenolic anti-aging agent represented by a general formula (1),

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(R1 represents an isopropyl group or a t-butyl group, and R2 represents an alkyl group having 1 to 12 carbon atoms), and the weight average molecular weight (Mw) of the acrylic rubber is in the range of 100,000 to 5,000,000.

A method for providing particles of polyvinyl chloride, wherein the particles offer improved chlorinating efficiency, the method comprising (i) providing polyvinyl chloride particles; and (ii) introducing a chlorination accelerant to the polyvinyl chloride particles to thereby provide polyvinyl chloride particles having an accelerant associated therewith.

A process for preparing an ethylene polymer in a suspension polymerization including the steps of separating the formed suspension of ethylene polymer particles in a solid-liquid separator into ethylene polymer particles and mother liquor, transferring a first part of the mother liquor into a work-up section including an evaporation unit for producing a wax-depleted portion of the mother liquor, wherein a protic agent is added to the part of the mother liquor which is transferred into the work-up section, and recycling a first part of the wax-depleted portion of the mother liquor to the polymerization reactor or the series of polymerization reactors.

The present invention relates to a superabsorbent polymer showing a low degree of decrease in absorption capacity, and a preparation method thereof. Specifically, the present invention provides a superabsorbent polymer having an excellent rewetting prevention ability such that moisture hardly leaks out under pressure even after a certain time, and a preparation method thereof, by preparing an acrylic resin with a high molecular weight main chain that is evenly cross-linked for maintaining high gel strength by minimizing an amount of an initiator with respect to a monomer.