Patent ID: 8535586

Claim:
A method of making crosslinked tri(2,4,6-trimethoxyphenyl) poly(vinylbenzyl chloride) quaternary phosphonium hydroxide (C-PVBC-QPOH-x%) ionomer membrane comprising: (a) preparing a mixture of poly(vinylbenzyl chloride) (PVBC) and tris(2,4,6-trirnethoxyphenyl) phosphine (TTMPP) dissolved in an aprotic solvent; (b) reacting said mixture at greater than 75° C. and for about 24 hours; (c) introducing a short chain crosslinker into said mixture during said reaction; (d) casting and curing the reaction mixture at temperature about or less than 30° C. for 24 hours to form a highly basic ionomer membrane; and (e) heating said membrane to about 135° C. for 3 hours to complete the cross linking reaction with membrane; (f) wherein said crosslinker is introduced to said mixture to achieve a desired degree of crosslinking (DCL) of said highly basic ionomer membrane; and (g) wherein the ion exchange capacity of the membrane is about or greater than 1.4 mmol/g.