摘要:
A method for purifying reclaimed polyethylene, such as polyethylene reclaimed from post-consumer use or post-industrial use, is disclosed. The method involves obtaining the reclaimed polyethylene and contacting it at an elevated temperature and pressure with a fluid solvent to produce an extracted reclaimed polyethylene. The extracted reclaimed polyethylene is dissolved in a solvent at an elevated temperature and pressure to produce a polyethylene solution, which is purified at an elevated temperature and pressure by contacting the polyethylene solution with solid media to produce a purer polyethylene solution. A purer polyethylene is then separated from the purer polyethylene solution.
摘要:
Provided is a process for producing a fluorinated copolymer which is capable of providing an ion exchange membrane which can suppress a decrease in current efficiency by impurities in an aqueous alkali chloride solution as a raw material on electrolysis of the alkali chloride aqueous solution. Also provided is a process for producing a fluorinated copolymer that comprises washing a fluorinated copolymer comprising a fluorinated monomer having a carboxylic acid type functional group and a fluorinated olefin, with a washing solvent containing a fluorinated solvent at a temperature of at least 40° C. and at most a boiling point of the washing solvent.
摘要:
Provided are systems and methods for separating a purge gas recovered from a polyethylene product. The method includes recovering a polyethylene product containing one or more volatile hydrocarbons from a polymerization reactor and contacting the polyethylene product with a purge gas to remove at least a portion of the volatile hydrocarbons to produce a polymer product having a reduced concentration of volatile hydrocarbons and a purge gas product enriched in volatile hydrocarbons. The purge gas product is compressed to a pressure of 2,500 kPaa to 10,000 kPaa, and is then cooled and separated into at least a first product, a second product, and a third product. A portion of one or more of the first, second, or third products is then recycled as a purge gas, to the polymerization reactor, or to the purge gas product enriched in volatile hydrocarbons prior to compression, respectively.
摘要:
Processes and systems for the production for pressure management of a polymerization product flowing from a loop polymerization reactor to a separation vessel in a slurry polymerization system are disclosed herein. For example, a process comprises withdrawing the polymerization product from a loop polymerization reactor, and conveying the withdrawn polymerization product to a separation vessel via a first pressure differential and a second pressure differential. The withdrawn polymerization product may flow through the first pressure differential before flowing through the second pressure differential, and the first pressure differential may be less than the second pressure differential.
摘要:
A process for reducing thermally induced discoloration of fluoropolymer resin produced by polymerizing fluoromonomer in an aqueous dispersion medium to form aqueous fluoropolymer dispersion and isolating said fluoropolymer from the aqueous medium to obtain the fluoropolymer resin. The process comprises: exposing the aqueous fluoropolymer dispersion to oxidizing agent.
摘要:
Process for reducing thermally induced discoloration of fluoropolymer resin produced by polymerizing fluoromonomer in an aqueous dispersion medium to form aqueous fluoropolymer dispersion and isolating said fluoropolymer from said aqueous medium to obtain said fluoropolymer resin. The process comprises: adjusting the pH of the aqueous medium of the aqueous fluoropolymer dispersion to greater than about 8.5; and exposing said aqueous fluoropolymer dispersion to an oxygen source.
摘要:
The present invention relates to an aqueous polymer dispersion whose dispersed addition polymer P comprises, copolymerized in free-radically polymerized form, at least one polar monomer having a water solubility of greater than 50 g/liter (measured at 20° C.), and obtainable by free-radically initiated aqueous emulsion polymerization, the polar monomer being metered to the reaction mixture during the polymerization process at a variable, i.e., nonconstant rate, for example in the sense of a rate gradient. The present invention further relates to processes for preparing these aqueous polymer dispersions, to their use as binders and/or in coatings, and also to coatings comprising the polymer dispersion of the invention.
摘要:
The present invention relates to an aqueous polymer dispersion whose dispersed addition polymer P comprises, copolymerized in free-radically polymerized form, at least one polar monomer having a water solubility of greater than 50 g/liter (measured at 20° C.), and obtainable by free-radically initiated aqueous emulsion polymerization, the polar monomer being metered to the reaction mixture during the polymerization process at a variable, i.e., nonconstant rate, for example in the sense of a rate gradient. The present invention further relates to processes for preparing these aqueous polymer dispersions, to their use as binders and/or in coatings, and also to coatings comprising the polymer dispersion of the invention.
摘要:
The invention relates to a method for the production of protective colloid-stabilized polymer products by means of emulsion polymerization in a reactor having an external cooling circuit, which is equipped with a pump and a heat exchanger, characterized in that the reaction mixture present in the reactor is delivered to a cooled static mixer-heat exchanger having stationary fixtures and is subsequently returned to the reactor. The invention further relates to a device for the production of protective colloid-stabilized polymer products by means of emulsion polymerization, comprising a reactor and an external cooling circuit, characterized in that the external cooling circuit is equipped with a pump and a cooled static mixer-heat exchanger having stationary fixtures.
摘要:
Evaporator apparatus (1) for the treatment of viscous media comprised of at least a feed chamber (2) having a perforated tray (3), a tube-bundle heat exchanger (4) connected thereto having perpendicularly arranged tubes (8) and a devolatilization chamber (5) connected thereto, a discharge unit (6) for the product and a vapor take-off (7) for removing volatile components, the tubes (8) of the heat exchanger (4) having a rectangular cross section over the greater part of their length.