摘要:
A process may include contacting an olefin monomer and a racemic bridged metallocene catalyst at a temperature of 80° C. to 150° C. in the presence of hydrogen. The racemic bridged metallocene catalyst may include a metallocene compound (A) and an activator component (B). The process may include recovering an effluent containing polyalpha-olefins (PAOs). The metallocene compound (A) may be represented by the formula R(Cp1)(Cp2)MX1X2. In the formula, R may be a C1-C20 alkylene bridging group; Cp1 and Cp2 may be the same or different substituted or unsubstituted tetrahydroindenyl rings; M may be a transition metal; and X1 and X2 may be independently selected from hydrogen, halogen, hydride radicals, hydrocarbyl radicals, substituted hydrocarbyl radicals, halocarbyl radicals, substituted halocarbyl radicals, silylcarbyl radicals, substituted silylcarbyl radicals, germlcarbyl radicals, substituted germylcarbyl radicals.
摘要:
supported catalyst system may include a titanated silica-containing catalyst support having at least 0.1 wt % of Ti and a specific surface area of from 150 m2/g to 800 m2/g. The Ti may be of a titanium compound of the general formula selected from RnTi(OR′)m, and (RO)nTi(OR′)m, wherein R and R′ are the same or different and are selected from hydrocarbyl groups containing from 1 to 12 carbons or halogens, wherein n is 0 to 4, wherein m is 0 to 4, and wherein m+n equals 4. The supported catalyst system may include a catalyst activating agent and a metallocene. The supported catalyst system may be obtained by a process including titanating a silica-containing catalyst support with at least one vapourised titanium compound, and treating the titanated silica-containing catalyst support with a catalyst activating agent and a metallocene.
摘要:
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.
摘要:
Processes for preparing a polyethylene in at least one continuously stirred tank reactor are described herein. The process may comprise the step of: polymerizing ethylene in the presence of at least one supported metallocene catalyst, a diluent, optionally one or more co-monomers, and optionally hydrogen, thereby obtaining the polyethylene, wherein the supported metallocene catalyst comprises a solid support, a co-catalyst and at least one metallocene, wherein the solid support has a surface area within the range of from 100 to 500 m2/g, and has a D50 value within the range of from 4 μm to 18 μm, with D50 being defined as the particle size for which fifty percent by weight of the particles has a size lower than the D50; and D50 being measured by laser diffraction analysis on a Malvern type analyzer. Polyethylene obtained by the disclosed process and articles comprising the polyethylene are also described.
摘要:
Processes for preparing a polyethylene in at least one continuously stirred tank reactor are described herein. The process may comprise the step of: polymerizing ethylene in the presence of at least one supported metallocene catalyst, a diluent, optionally one or more co-monomers, and optionally hydrogen, thereby obtaining the polyethylene, wherein the supported metallocene catalyst comprises a solid support, a co-catalyst and at least one metallocene, wherein the solid support has a surface area within the range of from 100 to 500 m2/g, and has a D50 value within the range of from 4 μm to 18 μm, with D50 being defined as the particle size for which fifty percent by weight of the particles has a size lower than the D50; and D50 being measured by laser diffraction analysis on a Malvern type analyzer. Polyethylene obtained by the disclosed process and articles comprising the polyethylene are also described.
摘要:
Poly(carbonate-urethane) or poly(ester-urethane) may be characterised in that of carbonate soft segments have molecular weights Mn ranging between 10,000 and 250,000 g/mol. The segments' length may be monitored by the ring-opening polymerisation condition. The process of preparing the poly(carbonate-urethane) or poly(ester-urethane) may include immortal ring-opening polymerisation of a cyclic carbonate or of a cyclic ester or diester monomers in the presence of a first catalyst system and diols or polyols. The process may include chemical modification of the hydroxyl chain-end groups into carboxylic groups in the presence of a second catalyst system. The process may include a coupling reaction with at least 2 equivalents of a second cyclic carbonate, enabling coupling with the carboxylic moiety in the presence of a third catalyst system. The process may include polyaddition of a diamine or a of amine via ring-opening of the second cyclic carbonate, and obtention of poly(carbonate-urethane) or poly(ester-urethane).
摘要:
The invention relates to a process and an installation to produce a monovinylaromatic polymer (3) comprising post-consumer recycled polystyrene (PCR-PS) wherein the process comprises the steps of mixing the PCR-PS (5) and the monovinylaromatic monomer (7) within a dissolver (9) to dissolve the PCR-PS (5) in the monovinylaromatic monomer (7) so as to produce a polymerization mixture (13); and a step of filtering the polymerization mixture (13) that includes continuously redirecting at least a part of the stream of the filtered polymerization mixture (17) back to the dissolver (9) and mixing it with the polymerization mixture (13) so as to continuously reduce the content of insoluble material in the polymerization mixture (13) contained in the dissolver (9).
摘要:
The invention relates to a process and an installation to produce a monovinylaromatic polymer (3) comprising post-consumer recycled polystyrene (PCR-PS) wherein the process comprises the steps of mixing the PCR-PS (5) and the monovinylaromatic monomer (7) within a dissolver (9) to dissolve the PCR-PS (5) in the monovinylaromatic monomer (7) so as to produce a polymerization mixture (13); and a step of filtering the polymerization mixture (13) that includes continuously redirecting at least a part of the stream of the filtered polymerization mixture (17) back to the dissolver (9) and mixing it with the polymerization mixture (13) so as to continuously reduce the content of insoluble material in the polymerization mixture (13) contained in the dissolver (9).
摘要:
The invention relates to a process and an installation to produce a monovinylaromatic polymer (3) comprising post-consumer recycled polystyrene (PCR-PS) wherein the process comprises the steps of mixing the PCR-PS (5) and the monovinylaromatic monomer (7) within a dissolver (9) to dissolve the PCR-PS (5) in the monovinylaromatic monomer (7) so as to produce a polymerization mixture (13); and a step of filtering the polymerization mixture (13) that includes continuously redirecting at least a part of the stream of the filtered polymerization mixture (17) back to the dissolver (9) and mixing it with the polymerization mixture (13) so as to continuously reduce the content of insoluble material in the polymerization mixture (13) contained in the dissolver (9).
摘要:
A process for manufacturing defined functional lactic acid oligomers, can include contacting lactide with at least one compound that is a transfer agent. Oligomers can be prepared according to the process.