The present invention provides a method for preparing a modified and conjugated diene-based polymer, which may prevent processability degradation by restraining the increase of mooney viscosity during post-treatment using steam with high temperature or storage for a long time by stabilizing a modified polymer using a modification stabilizer, and a modified and conjugated diene-based polymer prepared by the preparation method.

A system and method for a first reactor to produce a transfer slurry having a first polyolefin polymerized in the first reactor, a heat-removal zone to remove heat from the transfer slurry, and a second reactor to receive the transfer slurry cooled by the heat-removal zone, the second reactor to produce a product slurry having a product polyolefin which includes the first polyolefin and a second polyolefin polymerized in the second reactor.

The present invention relates to a process for operating a polymer powder degasser vessel, and in particular provides a process for operating a polymer powder degasser vessel which vessel comprises a silo comprising a main vertical cylinder and a hopper at the bottom of the cylinder, there being a polymer powder withdrawal pipe connected to the hopper by which polymer powder is withdrawn from the hopper, and wherein the silo contains a polymer powder which occupies less than 45% of the volume of the silo and the polymer powder passes through the polymer powder degasser vessel in a mass flow manner, further wherein at least one of the following is applied: i) polymer powder is withdrawn from the hopper and recirculated to the silo, wherein the recirculation rate of the polymer powder is at least 30 percent per hour of the polymer powder present in the silo, and ii) a purge gas is provided to the silo via the polymer powder withdrawal pipe or via an inlet located on the hopper at a vertical height which is less than half of height of the hopper from its bottom end.

This disclosure describes polymerization processes and processes for quenching polymerization reactions using high molecular weight polyhydric quenching agents.

The present invention relates to a method of preparing an aromatic vinyl compound-vinyl cyanide compound polymer including a step of separating volatile components from a polymerization product containing an aromatic vinyl compound-vinyl cyanide compound polymer, a residual aromatic vinyl monomer, a residual vinyl cyanide monomer, and an organic solvent using a volatilization tank, and a step of condensing the separated volatile components using a condenser, wherein an organic solvent or an aromatic vinyl monomer is sprayed onto the volatile components being transferred to the condenser. Volatile components may be fully condensed in a condenser, thereby significantly reducing the amount of volatile components discharged to the outside without being condensed. Therefore, wastewater treatment costs consumed in treating the volatile components may be reduced, and the amount of vinyl cyanide monomers harmful to the human body discharged into the atmosphere may be significantly reduced.

The present disclosure provides for a separations system for separating ethylene, 2-methylbutane and at least one unsubstituted (C6-C12) hydrocarbon in a multi-component condensate mixture. The separations system includes a feed conduit in fluid communication with a source of the multi-component condensate mixture, a stripper column in fluid communication with the feed conduit, where the stripper column separates the multi-component condensate mixture into a heavies component mixture with at least one unsubstituted (C6-C12) hydrocarbon, and a top mixture having a medium component (s) that include at least the 2-methylbutane and a light component (s) that include at least the ethylene. The separations system further includes a flash drum that separates the top mixture into the medium component (s) and the light component (s). The separations system does not include a distillation column disposed between the source of the multi-component condensate mixture and the flash drum.

Disclosed herein is an apparatus comprising a shell; the shell having an inlet port for introducing a polymer solution into the shell and an outlet port for removing the polymer solution from the shell; wherein the polymer solution comprises a polymer and a solvent that is operative to dissolve the polymer; a plurality of plates in the shell; where the plurality of plates is stacked one atop the other to define a central passage that is in fluid communication with the inlet port of the shell; where the plurality of plates further defines a plurality of conduits, each conduit extending radially outwards from the central passage, where the plurality of conduits is in fluid communication with the central passage; and where the apparatus is operated at a pressure and a temperature effective to maintain the polymer solution in a single phase during its travel through the apparatus.

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 a super absorbent resin, and the super absorbent resin can exhibit a fast absorption rate and high gel strength even in a partially swollen state through the size optimization of partially swollen gel particles. Therefore, the use of the super absorbent resin can effectively prevent a rewetting phenomenon.

Process for purification of unreacted vinyl acetate monomers comprising the steps of preliminarily loading an adsorbent agent bed with a mixture comprising an inert gas and fresh vinyl acetate; and feeding said adsorbent agent bed with unreacted vinyl acetate monomers to remove acetic acid.