摘要:
The invention relates to polyketone compounds and the at least partially hydrogenated products thereof, the use of said polyketone compounds and/or the at least partially hydrogenated products thereof as plasticizers, processes of making polyketone compounds and the at least partially hydrogenated products thereof, compositions comprising the polyketone compounds and/or the at least partially hydrogenated products thereof, and to articles formed from products of the invention.
摘要:
This invention relates to processes for producing an isotactic propylene homopolymer having more than 15 and less than 100 regio defects (sum of 2,1-erythro and 2,1-threo insertions and 3,1-isomerizations) per 10,000 propylene units; a weight-averaged molecular weight of 35000 g/mol or more; a peak melting temperature of greater than 149° C.; an mmmm pentad fraction of 0.85 or more; a heat of fusion of 80 J/g or more; and a peak melting temperature minus peak crystallization temperature (Tmp−Tcp) of less than or equal to (0.907 times Tmp) minus 99.64 (Tmp−Tcp
摘要:
A process for polymerizing olefins, comprising the steps of: (a) contacting in a dense-fluid-homogeneous-polymerization system (“PS”), >30 wt % C3+ olefins with: catalyst, activator, 0-50 mol % comonomer, and 0-40 wt % diluent/solvent, at a temperature > PS Tc and a pressure no lower than 1 MPa below the PS cloud point pressure and the polymer or above 80° C., whichever is higher; (f) separating the monomer-rich phase from the polymer-rich phase; (g) recycling the separated monomer-rich phase and recovering polymer from the polymer-rich phase.
摘要:
Provided are methods of producing polymers with broadened molecular weight and/or composition distribution in a continuous homogeneous polymerization system utilizing reactor temperature gradients, reactor polymer concentration gradients, monomer concentration gradients, catalyst concentration gradients, and combinations thereof in the polymerization reactor. Such methods are particularly suitable when utilizing metallocene catalysts and other single-site catalysts, which generally produce polymers with narrow molecular weight and composition distribution.
摘要:
An in-line fluid phase process for blending low crystallinity polymer components (LCPCs) and high crystallinity polymer components (HCPCs) to form pellet-stable polyolefin pellets is provided. The in-line process for producing the blend includes providing two or more parallel reactor trains and one or more separators for product blending and product-feed separation; wherein the two or more reactor trains producting the LCPC and HCPC blend components operate under fluid phase bulk homogeneous conditions, and at least one of the reactor trains operates under supercritical conditions. The HCPC blend component is a high crystallinity polypropylene-based polymer. The LCPC blend component is a low crystallinity ethylene-based or propylene-based polymer. The resultant blend pellets exhibit a reduced tendency or an eliminated tendency to agglomerate during shipping, handling and storage.
摘要:
A process for fluid phase in-line blending of plasticized polymers is provided. The process includes providing two or more reactor trains configured in parallel and a separator for product blending and product-feed separation, wherein one or more of the reactor trains produces one or more polymers and one or more of the reactor trains produces one or more plasticizers; contacting in at least one of the parallel reactor trains olefin monomers, catalyst systems, optional comonomers, optional scavengers, and optional diluents or solvents, at a temperature above the solid-fluid phase transition temperature of the polymerization system and a pressure no lower than 10 MPa below the cloud point pressure of the polymerization system and less than 1500 MPa; forming a reactor effluent including a homogeneous fluid phase polymer-monomer mixture and plasticizer-monomer mixture in each parallel reactor train; passing the reactor effluents through the separator; maintaining the temperature and pressure within the separator above the solid-fluid phase transition point but below the cloud point pressure and temperature to form a fluid-fluid two-phase system including a plasticized polymer-rich blend phase and a monomer-rich phase; and separating the monomer-rich phase from the plasticized polymer-rich blend phase. The polymer-rich blend phase is conveyed to a downstream finishing stage for further monomer stripping, drying and/or pelletizing to form a plasticized polymer product blend. Suitable plasticizers for in-line production and blending include polyalphaolefin oligomers, polybutenes, low glass transition temperature polymers and combinations thereof.
摘要:
Reactor designs and processes for operating such reactor designs to minimize or eliminate fouling in homogeneous polymerization processes (solution and supercritical). The process includes providing a reactor with one or more feed entry ports, wherein the reactor feed components are fed through each of the one or more feed entry ports at a linear velocity of greater than or equal to 0.3 m/min. The one or more feed entry ports may also be optionally extended beyond the interior reactor wall by greater than or equal to 2% of the internal radius of the reactor to further decrease the propensity for fouling. A stirred reactor may also include a stirrer feed port for purging the stirrer with a stirrer purge stream at a linear velocity of greater than or equal to 0.3 m/min to decrease stirrer fouling.
摘要:
Applications and users dynamically make QoS provisioning requests for individual traffic flows traversing client and server hosts. A traffic flow provisioning request is conveyed to a services manager, which determines a set of traffic attributes for the flow and determines the networks the flow traverses between the client and server hosts. The services manger then oversees the admission of the flow to appropriate traffic classes in each determined network and the obtaining of a DSCP value for each network. Lastly, the services manger conveys the DSCP value of the first network traversed back to the client or server host, depending on the direction of the flow, which host is then configured to appropriately mark the DSCP field of the traffic flow packets. In a further embodiment, the services manager also instructs the client or server host to perform packet policing and shaping for the flow.
摘要:
Provided are bulk homogeneous polymerization processes for producing ethylene propylene random copolymers. The process includes contacting in a reactor or in a series of reactors propylene monomer, ethylene comonomer with one or more catalyst systems and optional solvent (present at less than 40 wt %), wherein the reactor train is at a temperature of between 65° C. and 180° C. and at a pressure no lower than 10 MPa below the cloud point pressure of the polymerization system and less than 1500 MPa, and wherein the polymerization system for the reactor train is in its dense fluid state to form a polymer reactor effluent including a homogeneous fluid phase polymer-monomer mixture in the reactor train; and wherein the resultant copolymer product comprises between 10 wt % and 20 wt % randomly distributed ethylene and the concentration of total region defects in the continuous propylene segments of the random EP copolymer is between 40 and 150% greater than in a copolymer of equivalent melt flow rate and wt % ethylene polymerized by a solution polymerization process.
摘要:
An FET-based gas sensor includes at least one field-effect transistor and at least one gas-sensitive layer and a reference layer. Any changes in work function occurring when materials of the layers are exposed to a gas are used to trigger the field-effect structures. The gas-sensitive layer includes a metal oxide having an oxidation catalyst on its surface and accessible to the measured gas.