The Dow Chemical Company

Che I Kao

Michael E Rowland

Thoi H Ho

Pradeep Jain

Sarat Munjal

David A Eversdyk

Jimmy D Allen

Jose L Aguilar

Jeff H Stultz

Gary A Camp

Frederick Bernhard Kassell

R Bruce Combs

Greg A Winter

Elastomers with improved processability

A process for improving the green strength of ethylene/&agr;-olefin/diene polymers is described comprising (A) selecting an ethylene/&agr;-olefin/diene polymer having a Mooney viscosity at 125 C up to about 80 and a percent gel (% gel) up to about 30 percent and (B) partially crosslinking the ethylene/&agr;-olefin/diene polymer selected in step (A) to make a modified ethylene/&agr;-olefin/diene polymer satisfying the equations MV&lE;100 and

A solution polymerization system for polymerizing a olefin monomer by reacting the monomer with catalyst and solvent has been invented. The system in one aspect including a flow loop with a product polymer outlet, the flow loop forming a recycling reactor, a catalyst inlet on the flow loop through which catalyst and solvent flow into the flow loop, a monomer inlet on the flow loop through which monomer and solvent flow into the flow loop and, with the catalyst, form a reactant materials stream, a first heat exchanger on the flow loop for receiving the reactant materials stream and any formed polymer and for removing heat of reaction or polymerization from the flow loop, and pump apparatus for pumping the reactant materials stream and formed polymer in the flow loop and from the first heat exchanger to the product polymer outlet. In one aspect, the system includes at least one additional heat exchanger on the flow loop for receiving the reactant materials stream and formed polymer and for removing heat of reaction or polymerization from the flow loop, the pump apparatus pumping formed polymer and remaining reactant materials to the product polymer outlet, and a portion of the formed polymer and remaining reactant materials flowing out from the product polymer outlet and the remainder recycling through the flow loop. In one aspect systems and methods according to the present invention are used to make polyethylene.

Non-adiabatic olefin solution polymerization

A polycarbonate composition, and process for making same, wherein the monocarbonate and dicarbonate content is eliminated or limited to negligibly low levels by withholding introduction of chain terminator to the reaction mixture until the reaction of dihydroxy and carbonic acid derivative starting materials has run substantially to completion.

Elimination of monocarbonate from polycarbonate

High molecular weight polyhalobisphenol polycarbonates are produced by adding phosgene to a polyhalobisphenol in the alkali metal phenate form whereby the chloroformates of the bisphenol are formed and then adding an activated pyridine such as 4-aminopyridines or 2-substituted pyridines to generate a high molecular weight polycarbonate having an inherent viscosity in the range from about 0.4 to about 0.9.

Two stage catalytic production of high molecular weight

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Lake Jackson, TX, United States of America

Che I Kao