Analysis of the Size Distribution of Local Free Volume in Hyflon® Amorphous Glassy Perfluoropolymers by Photochromic Probes

In this paper the size distribution of free volume elements in amorphous glassy perfluorpolymer Hyflon® AD was evaluated. Films of the polymer, containing a series of stilbene and azobenzene photochromic probe molecules with different sizes, were prepared by solution casting. The photo-induced cis-trans isomerisation was studied and the degree of photo-isomerization was correlated with the size distribution of local free volume elements in the polymer matrix.