Semi-interpenetrating polymer networks based on polyaniline and polyvinyl alcohol–glutaraldehyde

A new semi-Interpenetrating Polymer Network (semi-IPN) based on polyvinyl alcohol–glutaraldehyde/polyaniline was synthesized and characterized by spectroscopic analysis in the UV–Visible–Infrared region and by scanning electron microscopy (SEM). The semi-IPNs exhibit good mechanical properties, characteristic of polyvinyl alcohol–glutaraldehyde polymer network, and excellent optical properties. The UV–Visible results show that the optical properties of the semi-IPNs are characteristic only of polyaniline polymer, and that the semi-IPNs are able to preserve the reduced or oxidized state of polyaniline for several months. The scanning electron microscopy of the semi-IPNs shown that phase separation occurs and the domains formed probably are due to polyaniline particle covered with an adsorbed layer of electrically insulating PVA stabilizer. The domains have a rice-grain morphology with average length of 1 μm, and average width of 0.5 μm for less cross-linked samples. The morphology of the phase domains change from rice-grain to spherical shape, as the cross-linking degree increases.