Preparation And Performance Of Novel Morpholine Quaternary Phosphonium Aems

As a key component of fuel cells,the research of anion exchange membranes(AEMs)still face many challenges.The poor alkaline stability and low ion conductivity of AEMs hinder the cooresponding application in commerce.In order to develop AEMs with excellent alkaline stability and high ion conductivity,the paper explored as follows.1.Using morpholine as the initial raw material,via five steps of reaction,the morpholinyl quaternary phosphonium salts TAAP and TAHP were synthesized and characterized,which were respectively loaded on the polyphosphazene and poly(2,6-dimethy-1,4-phenyleneoxide)(PPO).Two series of novel quaternary phosphonium salt AEMs were successfully prepared.The cooresponding tests were finished for the prepared AEMs,including mechanical properties,ion conductivity as well as alkaline stability.2.The TAAP-POH-45 membrane has good mechanical properties,and its ion conductivity at 80? reaches 33.5 mS·cm-1.After socked in 2 M KOH solution for 30 days,the ion conductivity was remained 94.3%of its initial value,showing excellent alkaline stability.PPO polymers loading TAHP quaternary phosphonium cations were prepared by quaternizing unsubstituted C-Br bonds with triethylamine.The prepared AEM has excellent mechanical properties,and the ion conductivity reaches a maximum of 48.5 mS·cm-1 at 80?.After socked in 2 M KOH solution for 10 days,the ion conductivity was remained 94.8%of its initial value,which is attributed to the unique structure of the quaternary phosphonium cation.3.The polyphosphazene membrane was blended with PVA,and was then cross-linked with glutaraldehyde(GA)under acidic conditions.A series of composite membranes with good alkaline stability and high ion conductivity were prepared.At 80?,the ion conductivity of the TAAP-PVA-50 composite membrane reached a maximum of 47.8 mS·cm-1.After socked in 2 M KOH solution at 60? for 30 days,the ion conductivity of composite membrane was remained 95%of its initial value.The current research in this article provides an effective method for improving the conductivity and alkaline stability of the quaternary phosphonium AEMs.