Preparation And Study Of Proton Exchange Membrane Of Double Proton Conductor Based On SPEEK

Proton exchange membrane fuel cell(PEMFC)is very important for future energy demand.As the core component of fuel cell,the performance of PEMFC is greatly affected by the performance of PEM.Nafion membrane is one of the most well-known proton exchange membrane materials.It has good comprehensive properties and can maintain high proton conductivity at low temperature,but it is expensive to manufacture and can not maintain high proton conductivity at high temperature and low humidity.When the temperature of PEMFC stack is higher than 80,a little dehydration will occur in Nafion membrane,which makes the proton transfer ability decrease sharply and seriously affects the performance of the membrane.Therefore,the preparation of low-cost proton exchange membranes which can operate normally at high temperatures is one of the key research directions at present.In this paper,SPEEK was used as the matrix material of proton exchange membranes.Two kinds of high temperature proton conductors,HEDP and 1-(3-aminopropyl)imidazole,were introduced to prepare the composite membranes,which were independent of water.The structure and properties of the composite membranes were characterized and analyzed.(1)With sulfonic acid and phosphonic acid as the main proton carriers,HEDP was chemically bonded to the organic silane system by the addition reaction between IPTES and HEDP,and then phosphonated organic siloxane was doped to the SPEEK matrix material to prepare the composite membrane.The reaction of IPTES and HEDP was successful by infrared spectroscopy.SEM cross-section showed that the composite membrane had perfect cross-linking structure.At the same time,the composite membranes prepared have good mechanical properties,thermal stability,oxidation resistance and hydrolysis resistance,and can exist stably in deionized water at 80.IEC and proton conductivity of composite membranes increased with the increase of HEDP content.Because of the existence of HEDP,the composite membrane still maintains high proton conductivity at high temperature and low humidity.The proton conductivity of AES-3 composite membrane can reach 0.0597 S/cm at 140.The composite membranes prepared have good comprehensive performance and can meet the working requirements of fuel cells.(2)IPTES and 1-(3-aminopropyl)imidazole were chemically bonded by addition reaction,then imidazolium organosiloxane was grafted into SPEEK material to prepare composite membrane.Infrared spectroscopy showed that IPTES and 1-(3-aminopropyl)imidazole reacted successfully.Siloxane in IPTES was hydrolyzed into Si-O-Si structure,and imidazole ring and sulfonate formed acid-base pairs.The properties of the composite membranes were tested.The results showed that the composite membranes had good hydrolysis resistance,mechanical properties,oxidation resistance and thermal stability.The composite film can operate in a wide temperature range(20-140),especially SPEEK-IM3,4 composite film,whose proton conductivity is over 0.04 S/cm at 140,which has a certain practical value.