Novel polyimide amic acid salts and polyimide membranes formed therefrom
AssigneePraxair Technology, Inc.
InventorsYong Ding, Benjamin Bikson, Joyce Katz Nelson, James Timothy Macheras
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Abstract
The invention relates to preparation and uses of novel polymeric materials, polyimide amic acid salts (PIAAS). The use of these materials for the fabrication of fluid separation membranes is further disclosed.
Claims24
A polyimide fluid separation membrane formed by thermal or chemical imidization of a polyimide amic acid salt precursor of the following general formula:
- 10
- where X is a protonated tertiary amine, a quaternary amine, a phosphonium ion, a sulfonium ion, or a mixture thereof and m and n are fractions from 0.025 to 0.95, and Ar and Ar′ are each either aliphatic or aromatic radicals.
A polyimide amic acid salt polymer having the following general formula:
- 19
- where X is a protonated tertiary amine, a quaternary amine, a phosphonium ion, a sulfonium ion, or a mixture thereof and m and n are fractions from 0.025 to 0.95, and Ar and Ar′ are aliphatic or aromatic radicals.
A polyimide formed by thermal or chemical imidization of polyimide amic acid salt precursor of the following general formula:
- 28
- where X is a protonated tertiary amine, a quaternary amine, a phosphonium ion, a sulfonium ion, or a mixture thereof and m and n are fractions from 0.025 to 0.95, and Ar and Ar′ are aliphatic or aromatic radicals.
A process for separating one or more gases from a mixture of gases comprising the steps of bringing said gaseous mixture into contact with a first side of a polyimide gas separation membrane such that a first portion of said gas mixture permeates to a second side of said membrane and a second portion of said gas mixture is collected as a nonpermeate, said first portion of said gas mixture being enriched in one or more components over that of said second portion of said gas mixture, wherein said polyimide gas separation membrane is formed via thermal or chemical imidization from a polyimide imide amic acid salt precursor.
Dependencies are inferred from the claim text.