Patent classifications
C08F6/10
Systems and methods for polyethylene recovery with low volatile content
The present invention discloses methods for removing volatile components from an ethylene polymer effluent stream from a polymerization reactor, and related polyethylene recovery and volatile removal systems. In these methods and systems, the polymer solids temperature is increased significantly prior to introduction of the polymer solids into a purge column for the final stripping of volatile components from the polymer solids.
Ultrafiltration of polyisoolefin copolymers and polyisoolefin copolymers with reduced oligomer content
A method of separating a polyisoolefin elastomer from non-polymeric components in an organic solvent involves ultrafiltration of a solution of the polyisoolefin elastomer and non-polymeric components in an organic solvent through a semipermeable membrane to substantially retain the polyisoolefin elastomer in a retentate and provide the non-polymeric components in a permeate. Advantageously, stabilizers for the polyisoolefin elastomer are retained in the retentate along with the polyisoolefin elastomer, permeate flux through the membrane is higher as concentration of the polyisoolefin elastomer in the solution increases up to a concentration limit, the separated polyisoolefin elastomer in the retentate has a molecular weight that can be substantially unchanged even when ultrafiltration is conducted at elevated temperature and the amount of polyisoolefin elastomer in the permeate is unmeasurable providing an oligomer-rich permeate uncontaminated by polyisoolefin elastomer. A process for curing a polyisoolefin copolymer involves reducing content of an oligomer to 900 ppm or less in a mixture of the oligomer and the polyisoolefin copolymer to produce an oligomer-depleted mixture, and adding a resin cure system to the oligomer-depleted mixture to cure the polyisoolefin copolymer.
Ultrafiltration of polyisoolefin copolymers and polyisoolefin copolymers with reduced oligomer content
A method of separating a polyisoolefin elastomer from non-polymeric components in an organic solvent involves ultrafiltration of a solution of the polyisoolefin elastomer and non-polymeric components in an organic solvent through a semipermeable membrane to substantially retain the polyisoolefin elastomer in a retentate and provide the non-polymeric components in a permeate. Advantageously, stabilizers for the polyisoolefin elastomer are retained in the retentate along with the polyisoolefin elastomer, permeate flux through the membrane is higher as concentration of the polyisoolefin elastomer in the solution increases up to a concentration limit, the separated polyisoolefin elastomer in the retentate has a molecular weight that can be substantially unchanged even when ultrafiltration is conducted at elevated temperature and the amount of polyisoolefin elastomer in the permeate is unmeasurable providing an oligomer-rich permeate uncontaminated by polyisoolefin elastomer. A process for curing a polyisoolefin copolymer involves reducing content of an oligomer to 900 ppm or less in a mixture of the oligomer and the polyisoolefin copolymer to produce an oligomer-depleted mixture, and adding a resin cure system to the oligomer-depleted mixture to cure the polyisoolefin copolymer.
Systems and Methods for Polyethylene Recovery with Low Volatile Content
The present invention discloses methods for removing volatile components from an ethylene polymer effluent stream from a polymerization reactor, and related polyethylene recovery and volatile removal systems. In these methods and systems, the polymer solids temperature is increased significantly prior to introduction of the polymer solids into a purge column for the final stripping of volatile components from the polymer solids.
Systems and Methods for Polyethylene Recovery with Low Volatile Content
The present invention discloses methods for removing volatile components from an ethylene polymer effluent stream from a polymerization reactor, and related polyethylene recovery and volatile removal systems. In these methods and systems, the polymer solids temperature is increased significantly prior to introduction of the polymer solids into a purge column for the final stripping of volatile components from the polymer solids.
Spiral heat exchanger as preheater in polymer devolatilization processes
This invention relates to a process for forming polymer including: polymerizing a monomer dissolved in a solvent in the presence of a catalyst system under conditions to obtain a first effluent stream including a solution of the polymer and the solvent; heating the first effluent stream in at least one spiral heat exchanger to produce a second effluent stream, where the first effluent stream flows through the spiral heat exchanger in a cross-flow direction relative to spirals of the spiral heat exchanger and performing a separation on the second effluent stream to produce: a third effluent stream including polymer substantially free of the solvent; and a recycle stream including the solvent and unreacted monomer. Processes for devolatilizing a polymer stream are also provided herein.
Solvent recovery apparatus and solvent recovery method
The present invention relates to a solvent recovery apparatus and a solvent recovery method, and the solvent recovery apparatus and method according to the present application can reduce the used amount of steam in a synthetic rubber production process, and can reduce the used amount of energy by recovering the waste heat discarded through a condenser.
Solvent recovery apparatus and solvent recovery method
The present invention relates to a solvent recovery apparatus and a solvent recovery method, and the solvent recovery apparatus and method according to the present application can reduce the used amount of steam in a synthetic rubber production process, and can reduce the used amount of energy by recovering the waste heat discarded through a condenser.
VINYL AROMATIC/DIENE-BLOCK COPOLYMERS HAVING GOOD ORGANOLEPTIC PROPERTIES
The invention relates to a vinyl aromatic/diene-block copolymer A, obtained by an anionic polymerization of a monomer composition, comprising: Al: 60-95 wt.-% of at least one vinyl aromatic monomer, and A2:5-40 wt.-% of at least one diene monomer, wherein the vinyl aromatic/diene-block copolymer A in total comprises less than 10 parts per million (ppm) of acetaldehyde, methacrolein and styrene based on the total amount of vinyl aromatic/diene-block copolymer A; the vinyl aromatic/diene-block copolymer A has improved orgnoleptic properties and is in particular suitable for producing food packaging materials.
VINYL AROMATIC/DIENE-BLOCK COPOLYMERS HAVING GOOD ORGANOLEPTIC PROPERTIES
The invention relates to a vinyl aromatic/diene-block copolymer A, obtained by an anionic polymerization of a monomer composition, comprising: Al: 60-95 wt.-% of at least one vinyl aromatic monomer, and A2:5-40 wt.-% of at least one diene monomer, wherein the vinyl aromatic/diene-block copolymer A in total comprises less than 10 parts per million (ppm) of acetaldehyde, methacrolein and styrene based on the total amount of vinyl aromatic/diene-block copolymer A; the vinyl aromatic/diene-block copolymer A has improved orgnoleptic properties and is in particular suitable for producing food packaging materials.