Thermal induced structural rearrangement of cardo-copolybenzoxazole membranes for enhanced gas transport properties

Yin Fong Yeong, Huan Wang, Kumari Pallathadka Pramoda, Tai Shung Chung*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

90 Scopus citations


We have successfully designed amendable polybenzoxazole materials with enhanced gas transport properties via incorporation of cardo moiety into thermally rearrangeable polymer chains. A series of cardo-copoly(hydroxyimide) have been synthesized by polycondensation of dianhydride with various molar ratios of two different ortho-functional diamine sources: 3,3'-dihydroxybenzidine (non-cardo) and 9,9-bis(3-amino-4-hydroxyphenyl)fluorene (cardo). The effect of cardo-containing diamine composition in the range of 5-50mol% on the structural and gas transport properties of the copolybenzoxazole membranes have been systematically investigated in the present work. It is found that the incorporation of cardo group has increased the gas permeability significantly. Thermally rearranged copolybenzoxazole membrane with the addition of 10mol% of cardo moiety has shown the largest enhancement in gas permeability. An increment of 3 times in CO 2 permeability has been achieved as compared to the CO 2 permeability in the non-cardo counterparts. The excellent features of the cardo-copolybenzoxazole shows a promising approach for the future cavity engineering in the field of high performance materials.

Original languageEnglish (US)
Pages (from-to)51-65
Number of pages15
JournalJournal of Membrane Science
StatePublished - Apr 15 2012

Bibliographical note

Funding Information:
This publication is made possible by the Singapore National Research Foundation under its Competitive Research Program for the project entitled, “New Biotechnology for Processing Metropolitan Organic Wastes into Value-Added Products” (grant number: R-279-000-311-281 ). The views expressed herein are solely the responsibility of the authors and do not necessarily represent the official views of the Foundation.” The authors would also like to express their appreciation to Dr. Pei Li, Mr. Yee Kang Ong, Mr. Jianzhong Xia, Mr. Panu Sukitpaneenit and Ms. Tingxu Yang for their assistances and valuable suggestions to this work. The authors are grateful to Mr. Poh Chong Lim for help on XRD experiments and Madam Yanhui Han for help on NMR experiments.


  • Cardo-copolybenzoxazole
  • Gas separation
  • High temperature copolymer
  • Membranes
  • Thermal rearrangement

ASJC Scopus subject areas

  • Biochemistry
  • Materials Science(all)
  • Physical and Theoretical Chemistry
  • Filtration and Separation


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