Premium
Effects of molecular structure on the permeability and permselectivity of aromatic polyimides
Author(s) -
Li Yuesheng,
Wang Xuqiang,
Ding Mengxian,
Xu Jiping
Publication year - 1996
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/(sici)1097-4628(19960801)61:5<741::aid-app4>3.0.co;2-o
Subject(s) - polyimide , bpda , membrane , polymer chemistry , permeability (electromagnetism) , gas separation , materials science , polymer , semipermeable membrane , chemical engineering , chemistry , composite material , biochemistry , engineering , layer (electronics)
Permeability coefficients of H 2 , O 2 , and N 2 were measured under 10 atm at the temperature from ambient temperature up to 150°C in a series of structurally different aromatic homo‐and copolyimides, which were prepared from 4,4′‐oxydianiline (ODA) or 4,4′‐methylene dianiline (MDA) with various aromatic dianhydrides. The study shows that the molecular structure of the polyimides strongly influences gas permeability and permselectivity. As a result, the permeability coefficients of the polyimide membranes for each gas vary by over two orders of magnitude. In general, among the polyimide membranes studied, the increase in permeability of polymers is accompanied by the decrease in permselectivity, and the MDA‐based polyimide membranes have higher permeability than ODA‐based ones. Among the polyimides prepared from bridged dianhydrides, the permeability coefficients to H 2 , O 2 , and N 2 are progressively increased in the order BPDA