Provided is a vinyl alcohol-based copolymer, obtained by saponifying a copolymer of vinyl acetate and a polyfunctional monomer, wherein the polyfunctional monomer contains two or more ethylenic double bonds in its molecule, the vinyl alcohol-based copolymer has a side chain containing an ethylenic double bond and a molar ratio (d) of the ethylenic double bond to a total of vinyl alcohol units and vinyl acetate units is from 0.05/100 to 2/100, and the vinyl alcohol-based copolymer is water soluble.

Continuity compositions are provided as are methods of their preparation. The compositions comprise metal carboxylate salts and fatty amines and find advantageous use in olefin polymerization processes.

Continuity compositions are provided as are methods of their preparation. The compositions comprise metal carboxylate salts and fatty amines and find advantageous use in olefin polymerization processes.

Process for producing a supported metallocene catalyst system includes: (i) preparing mixture (a) by mixing a metallocene with a cocatalyst; (ii) preparing mixture (b) by reacting an aluminium (II) with an amine (III)t;

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wherein each R6 and R10 is hydrogen or a C1-30 hydrocarbon; R7, R8, and R11 are C1-30 hydrocarbon; R9 is hydrogen or a functional moiety comprising at least one active hydrogen; (iii) providing a support material, into a reaction vessel; (iv) providing a solvent into the reaction vessel; (v) supplying mixture (a) and mixture (b) to the reaction vessel; (vi) subjecting the contents of the reaction vessel to a temperature of >60? C. for a period of >3 hrs to obtain a supported catalyst system; and (vii) removing the solvent from the supported catalyst system. Such process allows for the production of a supported metallocene catalyst system having reduced fouling in olefin polymerisation.

Process for producing a supported metallocene catalyst system includes: (i) preparing mixture (a) by mixing a metallocene with a cocatalyst; (ii) preparing mixture (b) by reacting an aluminium (II) with an amine (III)t;

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wherein each R6 and R10 is hydrogen or a C1-30 hydrocarbon; R7, R8, and R11 are C1-30 hydrocarbon; R9 is hydrogen or a functional moiety comprising at least one active hydrogen; (iii) providing a support material, into a reaction vessel; (iv) providing a solvent into the reaction vessel; (v) supplying mixture (a) and mixture (b) to the reaction vessel; (vi) subjecting the contents of the reaction vessel to a temperature of >60? C. for a period of >3 hrs to obtain a supported catalyst system; and (vii) removing the solvent from the supported catalyst system. Such process allows for the production of a supported metallocene catalyst system having reduced fouling in olefin polymerisation.

A method of transitioning from a first catalyst to a second catalyst in a gas phase fluidized bed reactor comprising continuously feeding the first catalyst and a recycle stream comprising olefin monomer to the reactor; wherein the monomer contacts the first catalyst in the fluidized bed and polymerizes; wherein the reactor is operating in condensing mode (withdrawing a gaseous stream comprising unreacted monomer from the reactor, cooling the gaseous stream to condense a portion thereof, and contacting the cooled gaseous stream with fresh monomer to form the recycle stream); and wherein a liquid phase of the recycle stream evaporates within the fluidized bed; discontinuing the first catalyst to the reactor while continuing to feed the recycle stream; maintaining the condensing mode in reactor at >3 wt. % liquid phase in recycle stream while no fresh catalyst is introduced to reactor; and introducing the second catalyst to the reactor operating in condensing mode.

A method of transitioning from a first catalyst to a second catalyst in a gas phase fluidized bed reactor comprising continuously feeding the first catalyst and a recycle stream comprising olefin monomer to the reactor; wherein the monomer contacts the first catalyst in the fluidized bed and polymerizes; wherein the reactor is operating in condensing mode (withdrawing a gaseous stream comprising unreacted monomer from the reactor, cooling the gaseous stream to condense a portion thereof, and contacting the cooled gaseous stream with fresh monomer to form the recycle stream); and wherein a liquid phase of the recycle stream evaporates within the fluidized bed; discontinuing the first catalyst to the reactor while continuing to feed the recycle stream; maintaining the condensing mode in reactor at >3 wt. % liquid phase in recycle stream while no fresh catalyst is introduced to reactor; and introducing the second catalyst to the reactor operating in condensing mode.

A method of transitioning from a first catalyst to a second catalyst in a gas phase fluidized bed reactor comprising continuously feeding the first catalyst and a recycle stream comprising olefin monomer to the reactor; wherein the monomer contacts the first catalyst in the fluidized bed and polymerizes; wherein the reactor is operating in condensing mode (withdrawing a gaseous stream comprising unreacted monomer from the reactor, cooling the gaseous stream to condense a portion thereof, and contacting the cooled gaseous stream with fresh monomer to form the recycle stream); and wherein a liquid phase of the recycle stream evaporates within the fluidized bed; discontinuing the first catalyst to the reactor while continuing to feed the recycle stream; maintaining the condensing mode in reactor at >3 wt. % liquid phase in recycle stream while no fresh catalyst is introduced to reactor; and introducing the second catalyst to the reactor operating in condensing mode.

A method of transitioning from a first catalyst to a second catalyst in a gas phase fluidized bed reactor comprising continuously feeding the first catalyst and a recycle stream comprising olefin monomer to the reactor; wherein the monomer contacts the first catalyst in the fluidized bed and polymerizes; wherein the reactor is operating in condensing mode (withdrawing a gaseous stream comprising unreacted monomer from the reactor, cooling the gaseous stream to condense a portion thereof, and contacting the cooled gaseous stream with fresh monomer to form the recycle stream); and wherein a liquid phase of the recycle stream evaporates within the fluidized bed; discontinuing the first catalyst to the reactor while continuing to feed the recycle stream; maintaining the condensing mode in reactor at >3 wt. % liquid phase in recycle stream while no fresh catalyst is introduced to reactor; and introducing the second catalyst to the reactor operating in condensing mode.

Disclosed herein are methods and compositions for reducing fouling by natural and synthetic foulants that tend to precipitate during petroleum collecting, processing, transporting, and storing. The method includes applying one or more antifouling polymers to a petroleum product to form a treated petroleum product, wherein fouling by the treated petroleum product is reduced and a stable dispersion is formed over a wide range of processing conditions. The one or more antifouling polymers include the polymerized residues of one or more ?-olefins and maleic anhydride, further wherein the maleic anhydride residues are reacted with a primary amine. Concentrates of the antifouling polymers in solvents are stable and pourable at temperatures of 0? C. to ?40? C.