Patent ID: 6833412
Filing Date: 2004-12-21
Classification: C08F,C08J,C08L,H01M,Y02E,Y02P

Abstract:
A method of making an acid functional fluoropolymer comprising the steps of:a) dehydrofluorinating a starting fluoropolymer with a dehydrofluorinating agent to form an unsaturated fluoropolymer; b) adding an acidifiable nucleophilic functionalizing agent to a double bond of the unsaturated fluoropolymer to form a fluoropolymer bearing an acidifiable function; and c) acidifying said acidifiable function; wherein said acid functional fluoropolymer is sufficiently acidified as to meet a condition selected from: a) the equivalent weight of the polymer is 5000 or less; and b) the proton conductivity of the polymer at 25Â° C. is 0.01 Siemens per centimeter (S/cm) or higher.