Abstract: Provided is a polycarbonate preparation method, comprising the following steps: a) mixing a phenoxide water aqueous solution of a bisphenol and/or a polyphenol with a phosgene and an inert organic solvent, reacting, and generating a polycarbonate oligomer; b) highly emulsifying the oligomer by reinforced micromixing to form a stable emulsion; and c) introducing the emulsion into a polycondensation reactor for a chain extending reaction, separating and finally obtaining the polycarbonate. Through the reinforced micromixing, the present method can prepare the high-molecular-weight polycarbonate without any catalysts, thus simplifying the post-treatment process of the product and improving product quality.

Abstract: A process for making a low density polymer in a polymerization reactor system, the process comprising polymerizing an olefin monomer, and optionally an olefin comonomer, in the presence of a diluent in a polymerization reactor to make a polymerization product slurry consisting of a liquid phase and a solid phase, wherein the solid phase comprises an olefin polymer having a density of between about 0.905 g/cm3 to about 0.945 g/cm3; and discharging the polymerization product slurry from the polymerization reactor through a continuous take-off valve to make a mixture further comprising a vapor phase. The mixture comprises a pressure less than a bubble point pressure of a component in the polymerization product slurry.

Abstract: This invention provides methods for controlled single electron transfer living radical polymerization (SET-LRP) of monomers with increased conversion, high molecular weights and low polydispersity by allowing the polymerization to proceed at low temperatures via a tubular reactor either made of copper or containing copper metal surface.

Abstract: The invention relates to a process for preparing polymers from monomers and/or oligomers by adding a liquid comprising the monomers and/or oligomers dropwise to a continuous liquid phase in a reactor, the continuous liquid phase being immiscible with the liquid comprising the monomers and/or oligomers, and the monomers and/or oligomers reacting in the continuous liquid phase to give the polymer. The liquid comprising the monomers and/or oligomers is shaped to droplets outside the continuous liquid phase, which are subsequently introduced into the continuous liquid phase. The invention further relates to a reactor for performing the process, comprising a tube through which a continuous liquid phase flows, and means of generating droplets, the means of generating droplets being arranged such that the droplets are generated outside the continuous liquid phase and then introduced into the continuous liquid phase.

Abstract: 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.

Abstract: PROBLEM There is provided a method for producing polylactic acid, which is capable of obtaining polylactic acid at low cost, and having high molecular weight. SOLUTION A method for producing polylactic acid by polymerizing molten lactide using at least one reactor having plug flow characteristics with ?(?), calculated from the following FORMULA (1), of 0.3 or smaller: ?(?)=?0?(E(?)×ABS(1??))d???(1) in the Formula (1), E(?) is a residence time distribution function determined by impulse response by starch syrup having a viscosity of 3 Pa·s, and ? is ratio of elapsed time ? and mean residence time ?0.

Abstract: A process for making a low density polymer in a polymerization reactor system, the process comprising polymerizing an olefin monomer, and optionally an olefin comonomer, in the presence of a diluent in a polymerization reactor to make a polymerization product slurry consisting of a liquid phase and a solid phase, wherein the solid phase comprises an olefin polymer having a density of between about 0.905 g/cm3 to about 0.945 g/cm3; and discharging the polymerization product slurry from the polymerization reactor through a continuous take-off valve to make a mixture further comprising a vapor phase. The mixture comprises a pressure less than a bubble point pressure of a component in the polymerization product slurry.

Abstract: Disclosed is an apparatus for producing a high-quality methacrylic polymer with good productivity, comprising a complete mixing type reactor 11, tubular reactors 12 and 13 which have been serially connected, and a volatile removing instrument 14, wherein at least two of the tubular reactors 12 and 13 are connected via a cooler 15 for cooling the reaction mixture. It is preferable that the cooler 15 is a multitubular cooler and the tubular reactors 12 and 13 are plug flow reactors.

Abstract: The present invention relates to a method for producing polyether carbonate polyols by way of the catalytic addition of carbon dioxide and alkylene oxides to H-functional starter compounds in the presence of double metal cyanide (DMC) catalyser that was activated in the presence of cyclic anhydride.

Abstract: A process for making a low density polymer in a polymerization reactor system, the process comprising polymerizing an olefin monomer, and optionally an olefin comonomer, in the presence of a diluent in a polymerization reactor to make a polymerization product slurry consisting of a liquid phase and a solid phase, wherein the solid phase comprises an olefin polymer having a density of between about 0.905 g/cm3 to about 0.945 g/cm3; and discharging the polymerization product slurry from the polymerization reactor through a continuous take-off valve to make a mixture further comprising a vapor phase. The mixture comprises a pressure less than a bubble point pressure of a component in the polymerization product slurry.

Abstract: Ethylene-based interpolymers, e.g., ethylene-acrylic acid copolymers, are made by a process comprising the steps of: A. Injecting a first feed comprising a chain transfer agent system (CTA system) and ethylene into a first autoclave reactor zone to produce a first zone reaction product, the CTA system of the first reactor zone having a transfer activity Z1; and B. (1) Transferring at least part of the first zone reaction product to a second reactor zone selected from a second autoclave reactor zone or a tubular reactor zone, and (2) at least one of transferring or freshly injecting a feed comprising a CTA system into the second reactor zone to produce a second zone reaction product, the CTA system of the second reactor zone having a transfer activity of Z2; and with the proviso that the ratio of Z1:Z2 is greater than 1. The comonomer comprises at least one carboxylic acid group or an anhydride group.

Abstract: The instant invention pertains to a process for preparing an ethylene homo- or copolymer in the presence of a supported chromium catalyst by slurry loop polymerization or copolymerization, whereby the resulting polymer powder has an increased powder density, in which the supported chromium catalyst has a chromium content of from 0.01 to 5 wt.-%, based on the element in the finished catalyst, and shows a particle size distribution measured according to ISO 13320-2009 comprising two main fractions one of which having a d50 of from 15 to 40 ?m and the other having a d50 of from 45 to 80 ?m said catalyst being further characterized by the fact that less than 10% wt of its catalyst particles has diameter lower than 20 ?m.

Abstract: In one preferred embodiment, the present invention provides a process for the liquid phase polymerization of isobutylene to manufacture highly reactive PIB oligomers having Mn under 1000, using a catalyst composition comprising a Friedel-Crafts catalyst a complexing agent, a chain transfer agent and a polymerization-retarding agent. A chain transfer agent may be selected from: ?-DIB and ?-DIB and mixtures thereof.

Abstract: Disclosed is an ethylene-based polymer with a density from about 0.90 to about 0.94 in grams per cubic centimeter, with a molecular weight distribution (Mw/Mn) from about 2 to about 30, a melt index (I2) from about 0.1 to about 50 grams per 10 minutes, and further comprising sulfur from about 5 to about 4000 parts per million. The amount of sulfur is also determined based upon the total weight of the ethylene-based polymer. Also disclosed is process for making an ethylene-based polymer which includes the steps of splitting a process fluid for delivery into a tubular reactor; feeding an upstream process feed stream into a first reaction zone and at least one downstream process feed stream into at least one other reaction zone, where the process fluid has an average velocity of at least 10 meters per second; and initiating a free-radical polymerization reaction.

Abstract: Catalyst compositions containing N,N-bis[2-hydroxidebenzyl]amine transition metal compounds are disclosed. Methods for making these transition metal compounds and for using such compounds in catalyst compositions for the polymerization of olefins also are provided.

Abstract: Techniques are provided for operating a reactor during a catalyst transition period. The instantaneous reaction rate during a catalyst transition period can be determined using real-time measured process variables, and material balance calculations to provide an instantaneous reaction rate in approximately real time. According to certain embodiments, a material balance can be performed on the reactor system using a continuous ideal stirred tank reactor to determine the fractions of each type of catalyst that are present in the reactor, as well as the overall weight percent of catalyst in the reactor. A controller can then calculate the overall instantaneous reaction rate based on the respective catalyst fractions and the overall weight percent of catalyst in the reactor. The catalyst feed rate can then be adjusted based on the determined instantaneous reaction rate to maintain the instantaneous reaction rate within desired limits during a catalyst transition period.

Abstract: The present invention relates to a method for feeding metallocene catalyst slurry to an olefin polymerization loop reactor (1) using a positive displacement device (5) positive displacement device comprising a first chamber and a second chamber, each chamber having an inlet and an outlet and each chamber comprising an ball arranged between the walls of said chamber, wherein said chambers are connected to each other by a pump chamber operably connected to a pump, wherein, the difference between the diameter of said ball and the diameter of said chamber is comprised between 5 to 200 times the average particle size (d50) of said catalyst.

Abstract: Process for polymerizing or copolymerizing ethylenically unsaturated monomers in the presence of free-radical polymerization initiators at pressures in the range of from 110 MPa to 500 MPa and temperatures in the range of from 100° C. to 350° C. in a continuously operated polymerization apparatus, wherein the reaction gas composition is compressed to the polymerization pressure by at least two sequentially operating compressors in which a low-pressure compressor first compresses the reaction gas composition to a pressure of from 10 MPa to 50 MPa and a high-pressure compressor then further compresses the reaction gas composition to the polymerization pressure wherein the high-pressure compressor is operated with a polyalkylene glycol based synthetic lubricant and oxygen is introduced into the fresh gas feed or into the polymerization apparatus in an amount that the gas composition to be compressed in the high-pressure compressor has an oxygen content in the range of from 0.01 ppm to 0.9 ppm.

Abstract: A process for preparing a polymer in the form of an aqueous dispersion or a water-redispersible powder includes free-radically initiated heterophase polymerization of one or more ethylenically unsaturated monomers and optionally subsequent drying of the polymer dispersions obtained, wherein the polymerization is performed in a jet loop reactor.

Abstract: Different interfacial processes for producing photoactive additives are disclosed. Generally, the photoactive additives are cross-linkable polycarbonate resins formed from a dihydroxybenzophenone, a first linker moiety, a diol chain extender, and an end-capping agent. The resulting additives can be crosslinked with other polymers upon exposure to UV radiation.

Abstract: The present invention relates to a low density polyethylene having a molecular weight distribution Mw/Mn which is greater than 15, a storage modulus G? (5 kPa) which is above 3000 and a vinylidene content which is at least 15/100k C, compositions, a process for production of the low density polyethylene, a continuous ethylene polymerization method for introducing vinylidene in a low density polyethylene, a method for an extrusion coating process, an article, e.g. an extrusion article, and use in extrusion coating.

Abstract: The present invention relates to slurry polymerisation, and in particular, to a slurry heater apparatus comprising at least two heating sections connected in fluid communication in series to form an initial slurry heater, wherein the slurry heater apparatus is adapted such that it can be reconfigured to form a subsequent slurry heater also comprising at least two heating sections connected in fluid communication in series, wherein the subsequent slurry heater has a different total length and/or a different average internal diameter than the initial slurry heater.

Abstract: A method of making a polyisobutylene polymer in a recirculating loop reactor with one or more reaction tubes in contact with a heat transfer medium includes: (a) providing a feed mixture consisting essentially of polymerizable monomer and catalyst to a residual reactor stream at a feed rate to form a reaction mixture, the reaction mixture containing less than 5% by weight diluent components; (b) recirculating the reaction mixture in the one or more reaction tubes of the loop reactor at a recirculation rate greater than the feed rate utilizing a recirculating pump operating at a pressure differential, delta P, corresponding to a recirculating flow; (c) polymerizing the reaction mixture in the one or more tubes of the loop reactor to convert the feed mixture to polyisobutylene polymer while cooling the one or more tubes of the loop reactor with the heat transfer medium; and (e) withdrawing polyisobutylene polymer from the loop reactor.

Abstract: A manufacturing system for producing polyolefin includes a polymerization reactor, a flash chamber, and a purge column. In certain embodiments, the purge column may receive a solids stream directly from the flash chamber. Further, the purge column may function as a feed tank for an extruder within an extrusion/loadout system. According to certain embodiments, the manufacturing system may be configured to consume less than 445 kilowatt-hours of energy per metric ton of polyolefin produced based on consumption of electricity, steam, and fuel gas.

Abstract: The invention relates to a process for preparing polyolefin in a loop reactor. The polymer is prepared by polymerizing olefin monomers in the presence of a catalyst to produce a polyolefin slurry while pumping said slurry through said loop reactor by means of a pump. The present process is characterized in that the catalyst is fed in the loop reactor at a distance to the pump. The invention allows production of the polymer with advantageous properties while leading to fewer blockages of the reactor.

Abstract: A system and method for producing polyolefin, including a polyolefin reactor system having: a first reactor to produce a first reactor discharge stream having a first polyolefin and a first diluent; and a second reactor to receive at least a portion of the first reactor discharge stream and to produce a second reactor discharge stream having a second polyolefin and a second diluent, wherein the second diluent is different than the first diluent.

Abstract: A polymerization reactor system includes features for operating two or more reactors in series or parallel. The system includes a discharge line coupled to an outlet of a first polymerization reactor, a first conduit connecting the first polymerization reactor to a second polymerization reactor via the discharge line, a second conduit connecting the first polymerization reactor to a flashline apparatus via the discharge line, and a diverter valve coupling the first and second conduits to the discharge line. The diverter valve is configured to selectively open the discharge line to the first conduit and close the discharge line to the second conduit in a first valve state and to selectively open the discharge line to the second conduit and close the discharge line to the first conduit in a second valve state. The diverter valve is capable of switching between the first and second valve states.

Abstract: A method of making a polyisobutylene polymer in a recirculating loop reactor with one or more reaction tubes in contact with a heat transfer medium includes controlling the delta P and polymerization reaction to provide a linear velocity of the reaction mixture of at least 11 ft/sec in the one or more tubes of the loop reactor and/or controlling the delta P and polymerization reaction of steps (b) and (c) to provide a recirculation ratio of the recirculation rate to the feed rate of at least 30:1. Typically, the process utilizes a recirculating pump operating at a pressure differential of from 35 psi to 70 psi.

Abstract: A process for the preparation of high purity propylene polymers carried out in the presence of a catalyst comprising the product obtained by contacting: (a) a solid catalyst component comprising Mg, Ti and at least a first internal electron donor compound (HD) selected among the succinates and a second internal electron donor compound (2ID) selected among the 1,3-diethers, wherein the molar ratio of first internal donor over second internal donor 1ID:2ID is comprised between 4:6 and 9:1, with (b) an organo-aluminium compound, and optionally with (c) an external electron donor compound, said process being carried out at a temperature equal or higher than 78° C. and by employing a molar ratio of organo-aluminum compound over solid catalyst component (b):(a) of lower than 5.

Abstract: A method for the copolymerization of ethylene and a C3+ olefin in a loop reactor and polymers formed therefrom are described herein. The method generally includes introducing an ethylene monomer, a C3+ olefin and a diluent carrier liquid into a loop reactor. A catalyst system can be supplied to said loop reactor. The diluent liquid, ethylene monomer, and C3+ olefin can be circulated through said loop reactor, while copolymerizing said ethylene and C3+ olefin in the presence of said catalyst system to produce a slurry. The slurry can be diverted into a settling leg, and sequentially discharged therefrom and withdrawn from said loop reactor. An ethylene monomer co-feed can be introduced into said loop reactor at spaced locations downstream of the ethylene and diluent. The ethylene co-feed can be introduced in an amount effective to reduce the variation in the ratio of ethylene and C3+ olefin.

Abstract: The invention relates to a process for the preparation of a particulate polyethylene product in a loop reactor, wherein the polymerization catalyst applied in the polymerization process comprises a particulate metallocene-alumoxane catalyst immobilized on a porous silica support; and whereby said metallocene-alumoxane catalyst is heterogeneously distributed on said porous silica support.

Abstract: The present invention relates to a process for the polymerization of an olefin monomer. In particular, the present invention relates to a process for the polymerization of an olefin monomer and one or more optional comonomers in presence of a polymerization catalyst and hydrogen, said process being characterized by an improved control of the hydrogen concentration in the polymerization reactor. In addition, the present invention provides for an improved hydrogen feeding system to a polymerization reactor. Furthermore, the present invention provides for a polymerization reactor comprising such an improved hydrogen feeding system.

Abstract: Methods and systems for preparing catalyst, such as chromium catalysts, are provided. The valence of at least a portion of the catalyst sent to an activator is changed from Cr(III) to Cr(VI). The catalyst is prepared or activated continuously using a fluidization bed catalyst activator.

Abstract: A process for the gas-phase copolymerization of: (a) propylene, (b) at least one C4-C8 ?-olefin, and (c) optionally ethylene, the process being carried out in a reactor having two interconnected polymerization zones, wherein the growing polymer particles flow through the first of said polymerization zones (riser) under fast fluidization conditions, leave said riser and enter the second of said polymerization zones (downcomer) through which they flow downward in a densified form, leave said downcomer and are reintroduced into said riser, thus establishing a circulation of polymer between the riser and the downcomer, the gas mixture present in the riser being at least partially prevented from entering the downcomer by introducing into the upper part of said downcomer a liquid barrier having a composition different from the gaseous mixture present in the riser and comprising at least one C4-C8 ?-olefin in a total amount of from 0.1% to 35% by mol.

Abstract: The present invention relates to a process for the production of propylene polymers in the presence of a blend of a first Ziegler-Natta catalyst, which comprises a titanium compound having at least one titanium-halogen bond and a diether compound as internal electron donor, and a second Ziegler-Natta catalyst, which comprises a titanium compound having at least one titanium-halogen bond and a succinate compound as internal electron donor.

Abstract: A reactor system including an enclosed pressure relief system and/or a control system. The enclosed pressure relief system including a slurry separation system communicatively coupled with a pressure relief valve coupled to a loop reactor such that activation of the pressure relief valve results in discharge of a slurry from the loop reactor to the slurry separation system, wherein the slurry separation system is capable of separating solid and liquid components from gas components of the slurry and transmitting the gas components to a flare via a flare header.

Abstract: Copolymers of ethylene and ?-olefins having (a) a density (D) in the range 0.900-0.940 g/cm3, (b) a melt index MI2 (2.16 kg, 190° C.) in the range of 0.01-50 g/10 min, (c) a melt index MI2 (2.16 kg, 190° C.) and Dow Rheology Index (DRI) satisfying the equation [DRI/MI2]>2.65, and (d) a Dart Drop Impact (DDI) in g of a blown film having a thickness of 25 ?m produced from the copolymer satisfying the equation DDI?1900×{1?Exp [?750(D?0.908)2]}×{Exp [(0.919?D)/0.0045]}. The copolymers may be prepared using metallocene catalysis and are preferably prepared in multistage processes carried out in loop reactors in the slurry phase. The copolymers exhibit long chain branching as defined by Dow Rheology Index (DRI) and exhibit unexpected improvements in mechanical properties, in particular dart drop impact, when extruded into blown films.

Abstract: Processes for the continuous production of conjugated polymers are disclosed. The processes provide excellent control over reaction parameters and are highly reproducible. The conjugated polymers find use in heterojunction devices.

Abstract: An ethylene polymer with a density of less than 955 kg/m3 obtained by polymerisation with a single-site catalyst and having a shear thinning index SHI2.7/210 of less than 5 wherein ethylene polymer comprises two components.

Abstract: The present invention relates to olefin polymers having associative groups containing nitrogen heterocyclic compounds, to hot-melt adhesives including such polymers, and to method for producing same. Specifically, the invention relates to a polymer comprising units from ethylene and from a monomer having associative groups, said monomer including a polymerizing reactive group and an associative group containing nitrogen heterocyclic compounds.

Abstract: A manufacturing system for producing polyolefin includes a polymerization reactor, a flash chamber, and a purge column. In certain embodiments, the purge column may receive a solids stream directly from the flash chamber. Further, the purge column may function as a feed tank for an extruder within an extrusion/loadout system. According to certain embodiments, the manufacturing system may be configured to consume less than 445 kilowatt-hours of energy per metric ton of polyolefin produced based on consumption of electricity, steam, and fuel gas.

Abstract: Polymerization reactor systems providing real-time control of the average particle size of catalyst system components are disclosed. Methods for operating such polymerization reactor systems also are described.

Abstract: A process comprising polymerising in a loop reactor an olefin monomer optionally together with an olefin commoner in the presence of a polymerisation catalyst in a diluent to produce a slurry comprising solid particulate olefin polymer and the diluent wherein the Froude number is maintained at or below 20 is disclosed.

Abstract: Polyamides, e.g., polyhexamethylene adipamide, are continuously produced via the following stages: Stage 1: into and through a reactor, polycondensing a liquid stream which contain the polyamide monomer(s) at a pressure P1 greater than atmospheric pressure, the stream of material at the outlet of the reactor including a vapor phase which contains steam and a liquid phase which at least contains the product of polycondensation; Stage 2: feeding the outlet stream of material into a chamber, evacuating at least a portion of the vapor phase therefrom and recovering at least the liquid phase which at least contains the product of polycondensation, the pressure P2 in the chamber being regulated at a set value such that it is greater than atmospheric pressure and the residence time of said liquid phase in the chamber being less than 5 minutes; and Stage 3: pressure reducing at least the liquid phase which at least contains the stream of polycondensation product recovered during Stage 2.

Abstract: A technique for polymerizing ethylene on catalyst in a first polymerization reactor and in a second polymerization reactor to form polyethylene particles, and controlling particle size of the polyethylene particles.

Abstract: Disclosed herein are polymerization processes for the production of olefin polymers. These polymerization processes use a catalyst system containing three metallocene components, often resulting in polymers having a reverse comonomer distribution and a broad and non-bimodal molecular weight distribution.

Abstract: The present invention relates to a reactor (10) and a process for continuous polymerization, where the reactor (10) has an essentially tubular reactor housing (16). The reactor housing (16) has a drive (38) which runs along the geometric central axis (12) in the flow direction (22) and is configured as a central shaft. A rotatably arranged scraper or wiper (36) is provided within the reactor housing (16); the scraper or wiper (36) has at least one scraper or wiper blade (42) to run along an interior side (44) of the reactor housing (16). The rotational movement of the scraper or wiper (36) results in radial mixing of a stream within the reactor housing (16) which dominates gravity effects and, by virtue of shaping of the scrapers or wipers, optionally makes plug flow or backflow within the reactor (10) possible.

Abstract: The present invention relates to a process for the preparation of polyether carbonate polyols from one or more H-functional starter compounds, one or more alkylene oxides and carbon dioxide in the presence of a double metal cyanide catalyst, wherein (?) the H-functional starter substance or a mixture of at least two H-functional starter substances is initially introduced into the reaction vessel, (?) for the activation, a part amount (based on the total amount of the amount of alkylene oxides employed in steps (?) and (?)) of one or more alkylene oxides is added to the mixture resulting from step (?), it also being possible for step (?) to be carried out several times for the activation, (?) one or more alkylene oxides and carbon dioxide are metered continuously into the mixture resulting from step (?) (“copolymerization”), the alkylene oxides employed for the copolymerization being identical to or different from the alkylene oxides employed in step (?), characterized in that in step (?) the carbon dioxide is

Abstract: The invention relates to a catalyst metering device with a valve formed of an iron-based alloy steel hardened to a Rockwell hardness C of at least 60. The device can be used for metering of a catalyst for an ethylene polymerization reaction. The invention further relates to ethylene polymerization wherein the catalyst is metered in a catalyst metering device with a iron-based alloy steel hardened valve, as well as to a ethylene polymerization reactor comprising such a catalyst metering device.

Abstract: The present invention relates to a reactor (10) and a process for continuous polymerization, where the reactor (10) has an essentially tubular reactor housing (16). The reactor housing (16) has a drive (38) which runs along the geometric central axis (12) in the flow direction (22) and is configured as a central shaft. A rotatably arranged scraper or wiper (36) is provided within the reactor housing (16); the scraper or wiper (36) has at least one scraper or wiper blade (42) to run along an interior side (44) of the reactor housing (16). The rotational movement of the scraper or wiper (36) results in radial mixing of a stream within the reactor housing (16) which dominates gravity effects and, by virtue of shaping of the scrapers or wipers, optionally makes plug flow or a loop flow or backflow within the reactor (10) or else via an additional external pumped circulation system (23) possible.