Modification of Poly(ether ether ketone) Polymer for Fuel Cell Application

Table 4

Solubility of P-PEEK acid and ester in various solvents.

Solvent	Phosphonated PEEK
	Room temp.	Temp. > 150°C
DMSO	C	C
DMAC	C	C
NMP	C	B
DMF	C	B
DMSO^+	C	B
DMAC^+	C	B
NMP^+	C	A
DMF^+	C	C
4-Chlorophenol^+	C	C
THF^+	C	C
Cyclohexanone^+	C	C

+Solvent and 2-3 drops of acid HBr/H₂SO₄, A: soluble, B: Sparingly soluble, C: not soluble.