Grafting poly(phenylene oxide) with poly(vinylphosphonic acid) for fuel cell membranes

Summary, in English

Densely phosphonated electrolyte membranes were prepared from poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) grafted with poly(vinylphosphonic acid) (PVPA) side chains. In the first step, PPO was lithiated in solution at room temperature by adding n-butyllithium to form an anionic macroinitiatior. Next, diethyl vinylphosphonate (DEVP) was anionically polymerized from the lithiated sites at -78 °C. This protocol gave good control over the density of the grafting sites and the copolymer composition. Films of copolymers containing between 35 and 74 wt% poly(diethyl vinylphosphonate) were first cast from solution, and subsequently fully hydrolyzed to produce transparent flexible proton conducting membranes of PPO-graft-PVPA containing up to 6 mmol phosphonic acid groups per gram dry copolymer. Thermogravimetric analysis showed anhydride formation at increasing temperatures above 100 °C with no copolymer degradation occurring until nearly 400 °C under air. Fully hydrated membranes reached proton conductivities above 1 mS/cm at -20 °C and 80 mS/cm at 120 °C.

• Författare: Mark Ingratta; Matti Elomaa; Patric Jannasch
• Avdelning/ar: Centrum för analys och syntes
• Publiceringsår: 2010
• Språk: Engelska
• Sidor: 739-746
• Publikation/Tidskrift/Serie: Polymer Chemistry
• Volym: 1
• Issue: 5
• Länkar: http://www.rsc.org/publishing/journals/PY/article.asp?doi=B9PY00390H; http://dx.doi.org/10.1039/b9py00390h
• Dokumenttyp: Artikel i tidskrift
• Förlag: Royal Society of Chemistry
• Ämne: Chemical Sciences
• Nyckelord: poly(vinylphosphonic acid); anionic graft polymerizations; polyelectrolytes; grafting; poly(phenylene oxide); polymer electrolyte membrane fuel cells; ionomers
• Status: Published
• ISBN/ISSN/Övrigt: ISSN: 1759-9954