Polyurethane latex modified with polyaniline

The strategy of the modification of polyurethane latex with a conducting polymer, polyaniline, is proposed. It is based on the introduction of the polymer steric stabilizer to the latex. The stabilizer prevents the macroscopic precipitation of a conducting polymer during the polymerization. Polyaniline has been prepared by the oxidative polymerization of aniline in the presence of polyurethane latex with average particle size of 36 nm and poly(N-vinylpyrrolidone). Thus, modified latex produces an aqueous colloidal dispersion having the particle size 100-200 nm. The presence of poly(N-vinylpyrrolidone) was needed to obtain a colloid. In its absence, a polyaniline-polyurethane composite precipitated. The composite coatings obtained after their drying contained 5-18 wt.% polyaniline in a protonated emeraldine form, had the conductivity up to 10−2 S cm−1, and mechanical properties typical of elastomers.