Polystyrene with perfluorinated side chain

The above data prove that the polystyrene-h-polybutadiene prepolymer is quantitatively transformed into block copolymers with perfluorinated side chains. The narrow molecular-weight distribution (I) = MW/MN) of the prepolymers is maintained by the described reaction sequence. 

It is mainly the PEM that distinguishes a PEM fuei ceii from aii other types of fuel cells. As its name implies, a PEM has the capability of transporting protons. It is typicaiiy made of a solid ionomer with acidic groups such as sulfonic acid (-SO3H) at the end of the polymer side chains. Polystyrene sulfonic acid is one such ionomer, and it was used as the PEM in the early days of the PEM fuel cell development around the 1960s. However, since the PEM fuel cell environment is warm, corrosive, and oxidative (at cathode), an ionomer with higher chemical and electrochemical stability is required. State-of-the-art PEMs are made of perfluorinated polysulfonic acids, and include DuPont s Nafion . 

---