Sulphonated Poly Ether Ether Ketone (SPEEK) -Azadirachta indica (AI) composite membranes have been prepared by varying AI from 0%, 1%, 2%, 3%, 4% and 5% while varying polymer content 100%, 99%, 98%, 97%, 96% and 95% by solution casting technique at 80 o C environment. The obtained films were subjected to Ion Exchange Capacity (IEC), Water Absorption (WA), Chemical Stability (CS), Protonic Conductivity (PC) with view to understand the compatibility for their utility in PEM Fue cell application.

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... I5 (SPEEK 95wt% + AI 5wt%) has maximum IEC, maximum WA, and minimum CS compared to pure SPEEK. The conductivity studies on the six selected samples show the maximum conductivity is noted for AI5. This may be reasoned that maximum WA with enhanced IEC only paved the way for good protonic transport mechanism. The FTIR studies confirms the Sulphonation of PEEK and complexation of SPEEK with AI. SEM shows the surface morphology of pure SPEEK and SPEEK/AI composite membranes, It is observed that beyond 5 weight% dispersion in SPEEK matrix, no free standing membrane is obtained which may be due to immiscibility of AI with SPEEK. Thus AI5 is the maximum dispersion of wood in SPEEK in the form of white patches and is found to be a critically compatible and viable membrane. XRD studies on PEEK, SPEEK, AI powder and SPEEK/AI composite membranes showed the transformation of semi-crystalline PEEK into amorphous membrane as part of introduction of SO 3 by sulphonation and making composite with AI. TGA studies confirms the sulphonation by the three step degradation as weight loss shown and ensured the membrane suitability to be used as PEM for PEMFC as there is no significant weight loss up to 230 °C and for PEMFC the operational temperature is very well below that. MEA prepared with pure SPEEK as well as SPEEK/AI5 membranes and subjected to realtime PEMFC testing which resulted in better OCV as well as power density.