Synthesis of Highly Sulfonated Poly(arylene ether) Containing Multiphenyl for Proton Exchange Membrane Materials

Table 1

IEC, water sorption, and dimensional stability of SP1 membranes.

Sample	IEC (mmol/g)	Degree of sulfonation (%)	Water uptake		(%)	(%)
SP1-0.39	0.39	10	14	20	5	1
SP1-2.22	2.22	56	120	30	27.5	8
SP1-2.80	2.80	70	372	74	105	28
SP1-2.90	2.90	73	—	—	—	—
Nafion 117	0.91	—	29	18	18	20

IEC determined by acid-base titration.
Calculated assuming six sulfonic acid groups per monomer unit. The theoretical highest IEC value of SP1- is 4.38 mmol/g (degree of sulfonation: 100%).
80°C in water.
Change in film length () and thickness () 80°C in water.
Dissolved in water.