Preparation And Characterization Of Proton Exehange Composite Membranes Based On Poly(phenyleneoxide) Sulfonation Product

The proton exchange membrane fuel cell (PEMFC) is widely used in theaerospace,military, electronic equipment and automotive industries. As the key part of PEMFC,the Proton Exchange Membrane (PEM) plays the roll of blocking fuel and oxidizer.So, it is very important to study the proton exchange membrane. At present, the mostwidely used PEM is Nafion (DuPont Company). Nafion membrane has manyadvantages such as high proton conductivity, good chemical stability and thermalstability. But there are also some disadvantages, such as expensive, protonconductivity depending on water too much. Which prevent the commercialdevelopment of Nafion. Therefore, it is necessary to developent cheap and goodperformance membranes.Poly (phenyleneoxide, PPO) is widely used as a thermoplastic material, it hasgood thermalstability, chemical stability and Mechanical properties (easy toprocessing), and Electrical properties can remain stable in a wide range of temperatureand humidity. These properties make PPO to become one of the ideal materials forproton exchange membrane.This research selected PPO as the fundamental material,and sulfonation PPO (SPPO) was prepared with chlorosulfonic acid, then, thePreparation, Structure and performance of SPPO was measured.Firstly, Polyethylene glycol (PEG) with different molecular weight,differentcontent was doped to the SPPO (sulfonation degree is52%) to get a series compositesmembranes.The results show that composite membranes’ performance is affected bythe molecular and content of PEG. The performance of the composite membranePEG600/SPPO(30/70) is the best. The conductivity is0.028S/cm at90℃，waterabortion and swelling ration are33%and6.4%respectively. Antioxidation timeand tensile strength are16h and41.6MPa respectively.Then, Polyacrylonitrile (PAN) with different content was doped to the SPPO(sulfonation degree is52%) to get a series composites membranes.The results showthat the water abortion and swelling ration improved, thermal stability is alsoimproved. The performance of the composite membrane PAN/SPPO(30/70) is thebest. The conductivity is0.0089S/cm at90℃, water abortion and swelling ration are27.4%and14.3%respectively. Antioxidation time is longer than72h, and tensilestrength is12.3MPa.Lastly, Polyvinylpyrrolidone (PVP) with different content was doped to the SPPO (sulfonation degree is52%) to get a series of SPPO composites. The results show thatwater absortion and water swelling are inproved, IEC and proton conductivitydecrease by The introduction of PVP. The performance of the composite membranePVP/SPPO(30/70) is the best. The conductivity is0.0043S/cm at90℃，waterabortion and swelling ration are6.6%and11.8%respectively. Antioxidation time islonger and tensile strength are9/20（h/min）and21.0MPa respectively.