In order to determine if light exposure provokes crosslinking of
celluloid, which should involve chemical reactions of nitrocellulose,
we used cellulose acetate as a model polymer to investigate the
mechanical and thermal properties of cellulose nitrate. We characterized
the network densification in the polymer bulk by DMTA
measurements and at the surface by AFM (thermal mode and
nanoindentation). The impact of photodegradation was first studied
by DMTA with respect to the storage modulus (E0) and loss
factor (tan d), as reported in Fig. 8.