Exxonmobil Chemical Patents Inc.

Exxonmobil Chemicals Patents, Inc.

Exxonmobile Chemicals Patents Inc.

Yifeng Hong

Jay L Reimers

John Robert Hagadorn

Shanshan Zhang

Anthony Jay Dias

Jun Shi

A method for monitoring polymerization processes can include reacting by polymerization a feedstock in the presence of a catalyst in a reactor to produce an effluent comprising a polymer and a solvent; measuring a density of the effluent; and calculating a monomer conversion rate and/or a polymerization rate for the polymerization based on the density of the effluent. A system for monitoring polymerization processes can include a reactor containing an effluent comprising a solvent, a polymer, and a monomer; a flash vessel fluidly coupled to the reactor to receive the effluent from the reactor; and an inline density meter fluidly coupled to the reactor, placed between the reactor and the flash vessel, and configured to measure a density of the effluent.

Solution polymerization process and product control using effluent density

This disclosure describes polymerization processes and processes for quenching polymerization reactions using reactive particulates, such as amorphous silica, as quenching agents, typically in solution or bulk polymerization processes.

Silica quenching agents for use in polymerization process

A method for producing block copolymers can include polymerizing a feedstock comprising a monomer and a comonomer under first polymerization conditions in the presence of a catalyst in a reactor to produce a first effluent comprising a first polyolefin block, an unreacted monomer, and an unreacted comonomer; blending the first effluent with a coordinative chain transfer polymerization agent to produce a mixture; and polymerizing the mixture in a separator under second polymerization conditions to cause the unreacted monomer and the unreacted comonomer to polymerize onto one end of the first polyolefin block as a second polyolefin block, thereby forming a block copolymer, wherein the first polyolefin block has a first comonomer content and the second polyolefin block has a second comonomer content that is different than the first comonomer content. The method can further include polymerizing in presence of a second coordinative chain transfer polymerization agent in a second separator.

Producing blocks of block copolymer in a separator downstream of a reactor

A method for producing a polyolefin with a wide molecular weight distribution can comprise: polymerizing one or more monomers in the presence of a catalyst system in a loop reactor to produce a polyolefin product having a polydispersity index of 2.5 to 8, wherein the loop reactor comprises two or more reactors in series, and wherein the loop reactor has a loop thermal gradient of 50&#xb0; C. to 150&#xb0; C. and/or a standard deviation of inter-component thermal gradients along the loop reactor of 10&#xb0; C. to 50&#xb0; C.

Broad molecular weight distribution polymer product from loop reactors with intentional thermal gradients

A process for the synthesis of a granular polymer, the process comprising (a) providing an active polymerization mixture that includes polymer, monomer, catalyst and optional solvent; (b) introducing a hydroxy-containing diaryl acetyl compound to the active polymerization mixture to thereby provide an inactive polymer mixture; (c) separating the polymer solution into a first stream and a second stream, where the first stream includes the polymer and the hydroxy-containing diaryl acetyl compound, and the second stream includes the monomer and the optional solvent; and (d) fabricating granules from the first stream.

Process for producing polymers

A method for producing gradient copolymers can include polymerizing a reaction mixture comprising a monomer and a comonomer in the presence of a metallocene catalyst in a loop reactor, wherein in the loop reactor a gradient monomer weight percent in the reaction mixture is about 3 wt % to about 50 wt %, thereby forming a gradient copolymer.

Production of gradient copolymers using monomer and comonomer concentration gradients in a loop reactor

A method broadening a molecular weight distribution and/or broadening a chemical composition distribution of the polyolefin product can include: polymerizing a feedstock in the presence of a metallocene catalyst in a loop reactor to produce a polyolefin product, the feedstock comprising two or more monomers; and adjusting a polymerization parameter selected from the group consisting of decreasing a recycle ratio, increasing a polymer concentration, increasing a LRSU number, and any combination thereof.

Controlling molecular weight distribution and chemical composition distribution of a polyolefin product

A method for determining polymer concentration can include synthesizing a polymer in a reactor under a set of parameters, wherein the reactor comprises a solution mixture having a refractive index, and wherein the solution mixture comprises a solvent, a polymer, and optionally a monomer, wherein the solution mixture has a polymer concentration; measuring the refractive index of the solution mixture; comparing the refractive index of the solution mixture with a calibration curve; and identifying the polymer concentration in the solution mixture. A system for determining polymer concentration can include a reactor containing a solution mixture comprising a solvent, a polymer, and optionally a monomer; a flash vessel fluidly coupled to the reactor to receive the solution mixture from the reactor; and a first refractometer fluidly coupled to the reactor, placed between the reactor and the flash vessel, and configured to measure a refractive index of the solution mixture.

Detection of polymer concentration in polymerization process using refractive index measurement

This disclosure describes polymerization processes and processes for quenching polymerization reactions using reactive particulates, such as lecithin, as quenching agents, typically in solution or bulk polymerization processes.

Lecithin quenching agent

This invention relates to a process for forming polymer including: polymerizing a monomer dissolved in a solvent in the presence of a catalyst system under conditions to obtain a first effluent stream including a solution of the polymer and the solvent; heating the first effluent stream in at least one spiral heat exchanger to produce a second effluent stream, where the first effluent stream flows through the spiral heat exchanger in a cross-flow direction relative to spirals of the spiral heat exchanger and performing a separation on the second effluent stream to produce: a third effluent stream including polymer substantially free of the solvent; and a recycle stream including the solvent and unreacted monomer. Processes for devolatilizing a polymer stream are also provided herein.

Spiral heat exchanger as preheater in polymer devolatilization processes

This disclosure describes polymerization processes and processes for quenching polymerization reactions using reactive particulates, such as high molecular weight functionalized olefin copolymers, as quenching agents, typically in solution or bulk polymerization processes.

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Houston, TX, United States of America

Yifeng Hong