摘要:
Embodiments disclosed herein generally relate to olefin polymerization catalysts, and more specifically to chromium-based catalysts and methods of use of chromium-based catalysts for the production of polyolefins, and even more specifically to methods for controlling or tailoring the flow index response of chromium-based catalysts through the controlled addition of a reducing agent to the catalysts under controlled mixing conditions.
摘要:
Embodiments disclosed herein generally relate to olefin polymerization catalysts, and more specifically to chromium-based catalysts and methods of use of chromium-based catalysts for the production of polyolefins, and even more specifically to methods for controlling or tailoring the flow index response of chromium-based catalysts through the controlled addition of a reducing agent to the catalysts under controlled mixing conditions.
摘要:
Broad molecular weight polyethylene and polyethylene having a bimodal molecular weight profile can be produced with chromium oxide based catalyst systems employing alkyl silanols. The systems may also contain various organoaluminum compounds. Catalyst activity and molecular weight of the resulting polyethylene may also be tuned using the present invention.
摘要:
Catalysts and methods for making and using the same are provided. The method for fabricating a catalyst may includes contacting a supported catalyst with a monomer under conditions that reduce an overall charge of the catalyst to less than about 75% of an initial charge of the catalyst. A method for polymerization may include introducing a pre-polymerized catalyst and one or more olefins into a gas phase fluidized bed reactor, operating the reactor at conditions sufficient to produce a polyolefin, wherein the polymerization is carried out in the substantial absence of any continuity additives.
摘要:
Catalysts and methods for making and using the same are provided. The method for fabricating a catalyst may includes contacting a supported catalyst with a monomer under conditions that reduce an overall charge of the catalyst to less than about 75% of an initial charge of the catalyst. A method for polymerization may include introducing a pre-polymerized catalyst and one or more olefins into a gas phase fluidized bed reactor, operating the reactor at conditions sufficient to produce a polyolefin, wherein the polymerization is carried out in the substantial absence of any continuity additives.
摘要:
Broad molecular weight polyethylene and polyethylene having a bimodal molecular weight profile can be produced with chromium oxide based catalyst systems employing alkyl silanols. The systems may also contain various organoaluminum compounds. Catalyst activity and molecular weight of the resulting polyethylene may also be tuned using the present invention.
摘要:
Catalysts and methods for making and using the same are provided. The method for fabricating a catalyst may includes contacting a supported catalyst with a monomer under conditions that reduce an overall charge of the catalyst to less than about 75% of an initial charge of the catalyst. A method for polymerization may include introducing a pre-polymerized catalyst and one or more olefins into a gas phase fluidized bed reactor, operating the reactor at conditions sufficient to produce a polyolefin, wherein the polymerization is carried out in the substantial absence of any continuity additives.
摘要:
A process for controlling the particle growth of a polymer in a gas phase polymerization reaction by using an inert particulate material and an unsupported liquid polymerization catalyst.
摘要:
Catalyst systems and methods for making and using the same. The catalyst system can include a single site catalyst compound, a support comprising fluorinated alumina, and an aluminoxane. The aluminoxane can be present in an amount of about 10 mmol or less per gram of the support.
摘要:
Disclosed herein is a polyolefin polymer having improved properties wherein the polymer is produced using a chromium based catalyst in combination with aluminum alkyl activators and co-catalysts. Also disclosed is a pipe comprising the inventive polymer and a film comprising the inventive polymer, each having improved properties over those known in the art.