The hydrolytic stability of some polyimides

Chemical sensing in two dimensional porous covalent organic nanosheets

“…The existence of enol-to-keto tautomerization provides the chemical stability for TpBDH, whereas the chemical stability in TfpBDH is possibly due to the presence of imide functionalities near the imine bonds, which decreases the electrophilicity of -C]N bonds through the mesomeric effect. 11 The surface area of acid treated TpBDH decreases slightly (642 to 517 m 2 g À1 ), whereas the water treated sample holds the usual surface area (642 to 627 m 2 g À1 ). However, for TfpBDH, the values decrease signicantly for both water and acid treated samples [from 738 to 541 m 2 g À1 (for water) to 375 m 2 g À1 (for acid)].…”

Application of 19F-NMR Toward Chemistry of Imide Materials in Solution

“…Hydrolytic stability of polyimides in the solid state has been investigated in terms of its effects on mechanical properties [64][65][66] or viscosity changes. 67 Additionally, chemical changes have been investigated by FTIR 68 and model-compound studies. 69 Some instances of polyimide failure during use in high-water-content environments have also been published.…”