RESEARCH ARTICLE Glutaraldehyde cross-linked sulphonated poly styrene ethylene butylene poly styrene membranes for methanol fuel cells Perumal Bhavani & Dharmalingam Sangeetha Received: 28 April 2012 /Accepted: 19 January 2015 # Central Institute of Plastics Engineering & Technology 2015 Abstract New, cheap proton conducting crosslinked membranes based on sulphonated poly styrene ethylene butylene poly styrene (SPSEBS) and glutaralde- hyde (2 to 10 %) were synthesized as substitute for costly Nafion117 membrane. Glutaraldehyde was used as the cross-linking agent in order to improve dimen- sional stability. The proton conductivity of the crosslinked membranes was in the order of 10 -2 S/cm at 25 °C. Proton exchange membrane fuel cell achieved the maximum power density of 68 and 58 mW/cm 2 , at a current density of 200 mA/ cm 2 for cross-linked membranes with glutaraldehyde content 2 and 10 % respec- tively. The methanol permeability of the cross-linked membrane (in the range of 16.22 to 11. 89×10 -7 cm 2 /s) was much lower than that of Nafion 117 (35.2× 10 -7 cm 2 /s). Direct methanol fuel cell (2 M concentration at 25 °C) consisting of cross-linked membrane was assembled and systematically examined. The crosslinked membranes containing 2 and 10 % glutaraldehyde showed maximum power density of 56 and 67.5 mW/cm 2 , respectively. The performance of cross- linked membranes in both the cells was several times higher than that of Nafion 117. Hence the cross-linked membrane is a viable substitute for Nafion 117 for fuel cells applications. In this study the formation of sulphonated PSEBS and cross-linked structure was ascertained through FTIR and X-ray diffraction spectra, scanning electron microscopy and thermal analysis. Keywords Cross linkedmembrane . PEMFC . DMFC . SPSEBS . Methanolpermeability Introduction The proton exchange membrane fuel cell and direct methanol fuel cell are a promising environmentally friendly and efficient power source for cars, buses, building, and in the miniaturized form, also for computers, mobile communication Int J Plast Technol DOI 10.1007/s12588-015-9103-6 P. Bhavani : D. Sangeetha (*) Department of Chemistry, Anna University, Chennai 600 025, India e-mail: sangeetha@annauniv.edu