Doping of polyaniline with a new family of protonating agents, namely sulfosuccinates with alkyl or alkoxy substituents, is discussed. The resulting polyaniline-sulfosuccinates exhibit a lamellar type structural organization in which stacks of polymer chains are separated by dopant anions. Although structurally similar to previously studied polyaniline-sulfophthalates, polyaniline-sulfosuccinates are better ordered and exhibit better physical properties. In particular, they exhibit metallic-type conductivity down to 210 K and they can be stretched at room temperature to elongations at break, Δl/lo, approaching 200%. Mechanical stretching does not affect the temperature range of the metallic conductivity, however, it does induce a 4-fold increase in the room-temperature conductivity of the polymer. Low Tg of polyaniline-sulfosuccinates is also the origin of the low temperature thermochromism a phenomenon reported so far only for polyaniline-sulfosuccinates and polyaniline-sulfophthalates. Finally, accelera...