Effective Conversion of Amide to Carboxylic Acid on Polymers of Intrinsic Microporosity (PIM-1) with Nitrous Acid
1
School of Chemical Sciences, The University of Auckland, Auckland 1142, New Zealand
2
School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney, Broadway NSW 2007, Australia
*
Authors to whom correspondence should be addressed.
Membranes 2018, 8(2), 20; https://doi.org/10.3390/membranes8020020
Received: 27 March 2018
/
Revised: 12 April 2018
/
Accepted: 12 April 2018
/
Published: 18 April 2018
(This article belongs to the Special Issue Polymeric Membranes for Gas Separation)
Carboxylate-functionalised polymers of intrinsic microporosity (C-PIMs) are highly desirable materials for membrane separation applications. The recently reported method to afford C-PIMs was via an extensive base hydrolysis process requiring 360 h. Herein, a novel and effective method to convert PIM-CONH2 to C-PIM using nitrous acid was studied. The chemical structure of C-PIM was characterised by 1H NMR, 13C NMR, FTIR, elemental analysis, UV-Vis, TGA and TGA-MS. Complete conversion from amide to carboxylic acid groups was confirmed. Decarboxylation of C-PIM was also successfully studied by TGA-MS for the first time, with a loss of m/z 44 amu (CO2) observed at the first degradation stage. TGA also revealed decreased thermal stability of C-PIM relative to PIM-CONH2 under both N2 and air atmosphere. Gel permeation chromatography (GPC) analysis showed continuous molecular weight degradation of C-PIM with extended reaction time. Aromatic nitration was also observed as a side reaction in some cases.
View Full-Text
▼
Show Figures
Figure 1
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
MDPI and ACS Style
Wu, W.-H.; Thomas, P.; Hume, P.; Jin, J. Effective Conversion of Amide to Carboxylic Acid on Polymers of Intrinsic Microporosity (PIM-1) with Nitrous Acid. Membranes 2018, 8, 20. https://doi.org/10.3390/membranes8020020
AMA Style
Wu W-H, Thomas P, Hume P, Jin J. Effective Conversion of Amide to Carboxylic Acid on Polymers of Intrinsic Microporosity (PIM-1) with Nitrous Acid. Membranes. 2018; 8(2):20. https://doi.org/10.3390/membranes8020020
Chicago/Turabian StyleWu, Wei-Hsuan, Paul Thomas, Paul Hume, and Jianyong Jin. 2018. "Effective Conversion of Amide to Carboxylic Acid on Polymers of Intrinsic Microporosity (PIM-1) with Nitrous Acid" Membranes 8, no. 2: 20. https://doi.org/10.3390/membranes8020020
Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.
