E.i. Dupont De Nemours and Company

Craig Robert Gochanour

Kenneth Wayne Leffew

Elwood Neal Blanchard

Jan M Stouffer

Disclosed is a process for the preparation of crystalline polycarbonate oligomer compositions from amorphous polycarbonate oligomer compositions in the presence of a fugitive crystallization rate enhancing agent and/or a high melting polymeric nucleating agent.

Process for the preparation of crystalline polycarbonate oligomers

Disclosed herein is a novel physical form of low molecular weight poly(trimethylene terephthalate). This form may be produced from molten low molecular weight poly(trimethylene terephthalate) material by means of rapid heat transfer from the material. The poly(trimethylene terephthalate) composition is suitable for use as a starting material for solid-state polymerization in order to produce polymers of higher molecular weight.

Production of poly(trimethylene terephthalate)

This invention is a gas separation membrane containing two polymer layers, a relatively thick layer, and an ultrathin layer, 10 to about 200 A thick. The ultrathin layer polymer is more selective than the polymer used in the thick layer. Also provided is a process for making such membranes.

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Wilmington, DE, United States of America

Craig Robert Gochanour