Effect of initial freezing temperature and comonomer concentration on the properties of poly(aniline-co-m-phenylenediamine) cryogels supported by poly(vinyl alcohol)

Abstract

Poly(aniline-co-m-phenylenediamine) cryogels supported by poly(vinyl alcohol) were obtained by oxidative cryocopolymerization of aniline and m-phenylenediamine in the presence of poly(vinyl alcohol) in the frozen aqueous medium. Morphology, specific surface area, and mechanical properties of aerogels obtained after freeze-drying with pore size up to 35 μm were dependent on initial freezing temperature and total concentration of comonomers in polymerization mixture. The materials initially frozen at higher temperatures and synthesized at higher comonomers concentrations were found to have in general smaller pore sizes and consequently better mechanical stability. Initial freezing temperature − 24 °C and total comonomer concentration 0.77 M were found to be the optimum parameters for the preparation of conducting cryogels with conductivity of solid phase 1 × 10−3 S cm−1, a relatively high specific surface area 23.1 m2 g−1, and excellent mechanical properties with tensile modulus 255 kPa. The molecular structure of cryogels is discussed with the help of FTIR and Raman spectra.