Ternary doping modified sulfonated polyphenylene sulfide proton exchange membrane and preparation method thereof

Abstract

The invention relates to a ternary doped and modified sulfonate polyphenylene sulfide proton exchange membrane and a method for preparing the ternary doped and modified sulfonate polyphenylene sulfide proton exchange membrane. The proton exchange membrane comprises, by weight, 75-98.5% of sulfonate polyphenylene sulfide with the sulfonation degree ranging from 57% to 80% and 1.5-25% of ternary doped phases. Due to the fact that SPPS with the high sulfonation degree serves as base materials, the defects that the SPPS with the ultrahigh sulfonation degree is ultrahigh in water absorption and a composite membrane is poor in stability are overcome, and the certain water absorption of the composite membrane is guaranteed; due to the adoption of a rare-earth oxide nanometer yttria, phosphotungstic acid and polyphosphazene ramification ternary doping mode, the SPPS base materials and the doped materials react to improve comprehensive performance of the composite membrane.

Description

technical field [0001] The invention relates to a sulfonated polyphenylene sulfide proton exchange membrane and a preparation method thereof, in particular to a ternary doped modified sulfonated polyphenylene sulfide proton exchange membrane and a preparation method thereof. Background technique [0002] Sulfonated polyphenylene sulfide (SPPS) materials have become the research focus of proton exchange membranes for direct methanol fuel cells because of their high mechanical strength, good thermal stability and chemical stability. Use sulfonating reagents such as concentrated sulfuric acid to sulfonate polyphenylene sulfide (PPS), and introduce sulfonic acid groups into the main chain of PPS. Due to the sulfonic acid group hydrophilic phase and the benzene ring and carbon-sulfur bonds on the polymer backbone, etc. The existence of the hydrophobic phase can make the SPPS material have a certain proton conductivity, and the low synthesis cost, good mechanical strength and exce...

AI Technical Summary

Problems solved by technology

However, the sulfonation degree (DS) of this material will directly affect the performance of the proton exchange membrane in all aspects. The SPPS proton exchange membrane with low DS has good mechanical strength, alcohol resistance and thermal stability, but due to the sulfonic acid group The amount of is small, the separation of the two phases is not obvious, and its proton conductivity is not ideal, which hinders the electrochemical cycle reaction of the fuel cell

Although the SPPS proton exchange membrane with high DS has high proton conductivity, its mechanical strength is reduced, its water absorption rate and swelling are too high, and SPPS will degrade in methanol at high temperature, which seriously affects the stability of the membrane and fuel consumption. battery life

Because the degree of sulfonation has contradictory effects on the performance of proton exchange membrane materials, in the design of SPPS proton exchange membranes, it is usually necessary to comprehensively consider the degree of sulfonation and modification methods of SPPS, and it is not possible to lose sight of the other.