2015-Mechanically tough, thermally rearranged (TR) random/block poly(benzoxazole-co-imide) gas separation membranes
writer：Yongbing Zhuang, Jong Geun Seong, Won Hee Lee, Yu Seong Do, Moon Joo Lee, Gang Wang, Young Moo Lee*, Michael D. Guiver*
keywords：聚酰亞胺，氣體分離膜
source：期刊
specific source：Macromolecules
Issue time：2015年
Insufficient mechanical properties are one of the major obstacles for
the commercialization of ultrahigh permeability thermally rearranged
(TR) membranes in large-scale gas separation applications. The
incorporation of preformed benzoxazole/benzimidazole units into o-hydroxy
copolyimide precursors, which themselves subsequently thermally
rearrange to form additional benzoxazole units, were prepared for the
first time. Using commercially available monomers, mechanically tough
membranes prepared from random and block TR poly(benzoxazole-co-imide)
copolymers (TR-PBOI) were investigated for gas separation. The effects
of the chemical structures, copolymerization modes, and thermal holding
time of o-hydroxy copolyimides on the molecular packing and
properties, including gas transport, for the resulting TR-PBOI membranes
have been examined in detail. After treatment at 400 °C, tough TR-PBOI
membranes exhibited tensile strengths of 71.4–113.9 MPa and elongation
at break of 5.1–16.1%. Moreover, they presented higher or comparable gas
transport performance as compared to those tough/robust TR membranes
reported previously. Reported for the first time is a comparative
investigation of the copolymerization mode (random or block) on membrane
properties. The novel polymer architecture and systematic property
studies promote a better understanding of the materials and process
development of commercial TR membranes for gas separation applications.