Effect Of UV Rays On Degradation And Stability Of High Performance Polymer Membranes

¹Polymer Science and Engineering Division, Council of Scientific and Industrial Research, National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India

²Academy of Scientific and Innovative Research (AcSIR) 2, Rafi Marg, Anusandhan Bhavan, New Delhi 110001, India

³Bharati Vidyapeeth University, Advanced Research Centre in Pharmaceutical Sciences and Applied Chemistry, Erandawane, Pune 411038, India

Adv. Mater. Lett., 2014, 5 (5), pp 272-279

DOI: 10.5185/amlett.2014.10533

Publication Date (Web): Mar 09, 2014

Copyright © IAAM-VBRI Press

E-mail: rp.singh.ncl@gmail.com

Abstract

Acid doped polybenzimidazole membranes have emerged as an efficient electrolyte for high temperature polymer electrolyte membrane fuel cells (HTPEMFCs). The long term stability of polybenzimidazole membranes has been recognized as an important issue for commercial applications. Here, we report the oxidative degradation of polybenzimidazole membranes. The photoirradiation of poly(2,2'-ethylene-5,5'-bibenzimidazole) (PBIE) under accelerated photodegradation conditions was carried out by ultraviolet (UV) rays (λ > 300 nm) and characterized by Fourier transform infra red (FT-IR) spectroscopy, scanning electron microscopy (SEM), wide angle X-ray diffraction (WAXD) and contact angle measurements (CAM).  The thermal properties of PBIE membranes were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) which revealed a lowering in thermal stability after photodegradation. FT-IR spectra revealed high absorbance in the carbonyl region in photoirradiated membranes whereas SEM showed nano structures / defects on the polymer film surface. CAM results showed enhancement in hydrophilic behavior and WAXD revealed increase in amorphous nature upon irradiation.

Keywords

Degradation, fuel cell, high performance material, polybenzimidazole membranes, photodegradation, UV rays