The Dow Chemical Company

Daniel J Swart

Jacqueline S Kelyman

William J Kruper

Timothy S Stevens

William Charles Harris

Nile Nelson Frawley

Lawrence W Nicholson

Deborah E Diedering

L David Rothman

An analytical chemistry apparatus and method for introducing a reagent into a flowing stream of liquid carrier in order to quantitatively analyze one or more components of a sample added into the carrier. The reagent is permeated across a short section of membrane having relatively large pores. The use of such a membrane: (a) allows the membrane to be protected from physical damage by covering it with a perforate structure; (b) significantly reduces bandspreading across the membrane reagent addition device; (c) reduces the pressure drop across the membrane reagent addition device; and (d) still allows for the permeation of an effective amount of the reagent into the carrier. The reagent is preferably pressurized to minimize leakage of carrier across the membrane and the reagent can be self-pressurized by essentially completely filling the reagent reservoir of the invention with reagent and then hermetically sealing the reservoir.

Method for reagent addition to a flowing liquid carrier stream

Esterification of aromatic dicarboxylic acids with cyclic alkylene carbonates in the presence of organic compounds containing at least one six-membered aromatic nitrogen-containing heterocyclic moiety.

Esterification of aromatic dicarboxylic acids with cyclic alkylene

The invention is a process for the preparation of a carbon dioxide oxirane copolymer wherein the process comprises contacting carbon dioxide with an oxirane in the presence of (1) an organic coordination compound and (2) a catalytic amount of a double metal cyanide complex under conditions such that an oxirane carbon dioxide copolymer is prepared.

Carbon dioxide oxirane copolymers prepared using double metal cyanide

Alternating copolyestercarbonate resins having repeating units of the formula: ##STR1## wherein R.sup.1 is para-phenylene; each R is independently an aromatic hydrocarbylene or inertly substituted aromatic hydrocarbylene, e.g., ##STR2## and x is a number from 0.05 to 0.65 exhibit physical properties such as heat resistance, clarity and impact strength that are superior to the comparable properties of corresponding random copolymers. Such resins are useful for making transparent tough films and molded articles having high heat resistance.

Alternating copolyestercarbonate resins

Linear polyesters are produced by esterification of aromatic dicarboxylic acids with cyclic alkylene carbonates in the presence of organic compounds containing at least one six-membered aromatic nitrogen-containing heterocyclic moiety followed by polycondensation of the resulting low molecular weight ester.

Linear polyesters from aromatic dicarboxylic acids and cyclic alkylene

Alternating copolyestercarbonate resins having repeating units of the formula: ##STR1## wherein R.sup.1 is meta-phenylene and R is independently an aromatic hydrocarbylene or inertly substituted aromatic hydrocarbylene, e.g., ##STR2## exhibit physical properties such as heat resistance, clarity and impact strength that are superior to the comparable properties of corresponding random copolymers and exhibit physical properties such as impact strength and processability that are superior to the comparable properties of corresponding alternating copolyestercarbonates wherein R.sup.1 is para-phenylene. Such resins are useful for making transparent tough films and molded articles having high heat resistance.

Alternating copolyestercarbonate resins having repeating units of the formula: ##STR1## wherein each R is independently an aromatic hydrocarbylene or inertly substituted aromatic hydrocarbylene, e.g., ##STR2## exhibit physical properties such as heat and impact resistance that are superior to the heat and impact resistance of corresponding random copolymers. Such resins are useful for making transparent tough films and molded articles having high heat resistance.

Growing community of inventors

Midland, MI, United States of America

Daniel J Swart