In the highly competitive market of fuel cells, proton exchange membrane fuel cells operating in the range of 80-150 degrees C seem quite promising. One of the main hurdles for the emergence of such a technology is the development of phosphonic acid-based membranes characterized by high conductivity and stability beyond 80 degrees C. In this work, plasma polymers containing phosphonic acid groups have been successfully prepared using dimethyl allylphosphonate as a single precursor. Structural and transport properties of plasma polymers are logically correlated with the plasma discharge power. Under optimized plasma conditions, plasma films are thermally stable up to 150 degrees C and present the highest growth rate, concentration of ion exchange groups and proton conductivity, which make them competitive as membranes for fuel cells. (C) 2014 Elsevier B.V. All rights reserved.