The Dow Chemical Company

Dow Deutschland Inc.

William C Pike

Duane B Priddy, Sr

Jerry L Hahnfeld

Clinton J Boriack

James A Rabon, Jr

Lu H Tung

Chau Van Vo

Andrew N Paquet

Donald E Kirkpatrick

Jose M Rego

James M Roe

Peter Hendrikus Vollenberg

Timothy G Bee

The present invention is an improved process for producing high molecular weight monovinylidene aromatic polymers and polymodal compositions by free radical polymerization of a vinyl aromatic monomer in the presence of a vinyl acid, wherein the improvement comprises neutralizing the acid after production of the desired amount of high molecular weight monovinylidene aromatic polymer by adding a base.

Process for producing high molecular weight monovinylidene aromatic polymers and polymodal compositions

The present invention is an improvement in a free radical bulk polymerization process for preparing a high molecular weight polymer from a vinyl aromatic monomer characterized in that the polymerization is conducted in the presence of an acid catalyst having a pKa at 25.degree. C. of less than 2, or salt thereof, wherein the improvement comprises dispersing the acid catalyst, or salt thereof, in a (meth)acrylic acid or ester thereof, prior to contact with the vinyl aromatic monomer. The (meth)acrylic acid or ester allows the acid catalyst to be dispersed within the vinyl aromatic monomer without causing cationic polymerization. The acid catalyst, or salt thereof, catalyzes the free radical polymerization reaction such that high molecular weight polymers are produced in reasonable reaction times.

Acid catalyzed polymerization

A process for producing a branched polymer from a vinyl aromatic monomer comprising:

Preparation of branched polymers from vinyl aromatic monomer

A free radical polymerization process for producing a branched polymer from a vinyl aromatic monomer comprising polymerizing a vinyl aromatic monomer in the presence of a free radical initiator of the formula: ##STR1## wherein R is H, alkyl, or aralkyl, and R' is alkyl or aryl.

Process for preparing a branched polymer from a vinyl aromatic monomer

Disclosed is an extruded, linear, bimodal monovinyl aromatic polymer foam having a weight average molecular weight of from about 100,000 to about 200,000, greater than 5 percent by weight of its polymer chains having a weight average molecular weight of 500,000 to 1,000,000, and less than 5 percent by weight of its polymer chains having a weight average molecular weight of greater than 1,000,000. Use of the polymer enables process pressure drop to be significantly reduced and allows the formation of a foam of lower density and larger cross-section. Further disclosed is a process for making the extruded foam.

Extruded foams having a monovinyl aromatic polymer with a broad

Strong base anion exchange resins that contain quaternary ammonium groups derived from higher molecular weight amines, such as triethylamine or tripropylamine instead of trimethylamine, have a higher reactivity for catalyzing the reaction of an epoxide compound with an acid compound to form an ester.

Catalysts for reaction of epoxides and acids

Disclosed are novel ion-exchange and chelate-exchange resins having improved exchange kinetics for separating chemical species from liquids. The resins are prepared from copolymer beads consisting of a monovinyl aromatic monomer and a cross-linking monomer. The copolymer beads are functionalized such that weak-base exchange moieties are substituted at haloalkylated sites which are most accessible to diffusion into the beads, while hydrophilic, strong-base exchange moieties are substituted at haloalkylated sites which are least accessible to diffusion. The resins have improved exchange kinetics due to shortened diffusion path lengths for the chemical species being separated and improved diffusion into the resin beads due to the hydrophilic, strong-base exchange moieties.

Resins having improved exchange kinetics

The production of esters via the reaction of an epoxide with a carboxylic acid hasbeen shown to give improved activity when a strong base macroporous anion exchange resin having an acrylic backbone is used in place of a styrene-divinylbenzene based anion exchange resin having an equivalent exchange capacity. Excellent results are obtained when acrylic acid and propylene oxide are reacted together in the presence of strong base macroporous anion exchange resins which have an acrylic backbone.

Growing community of inventors

Midland, MI, United States of America

William C Pike