The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 24, 2018
Filed:
May. 22, 2015
Nitesh Bhuwania, Richmond, CA (US);
Shabbir Hussain, Emeryville, CA (US);
Daniel Chinn, Danville, CA (US);
John Wind, Berkeley, CA (US);
Stephen Miller, San Francisco, CA (US);
Nitesh Bhuwania, Richmond, CA (US);
Shabbir Hussain, Emeryville, CA (US);
Daniel Chinn, Danville, CA (US);
John Wind, Berkeley, CA (US);
Stephen Miller, San Francisco, CA (US);
Chevron U.S.A. Inc., San Ramon, CA (US);
Abstract
Disclosed herein is a method of making a crosslinked membrane such as a crosslinked hollow fiber membrane. The method comprises (a) preparing a polyimide polymer comprising carboxylic acid functional groups from a reaction solution comprising monomers and at least one solvent; (b) treating the polyimide polymer with a diol at esterification conditions to form a monoesterified polyimide polymer; (c) forming a monoesterified polyimide membrane or dense film from the monoesterified polyimide polymer; and (d) subjecting the monoesterified polyimide membrane or dense film to transesterification conditions under a COatmosphere to form a crosslinked polyimide membrane or dense film.