Synthesis of polyaniline nanofiber and copolymerization with acrylate through in situ emulsion polymerization

Polyaniline (PANI) was prepared, respectively, by direct mixed oxidation method in different acids. Scanning electron microscopy showed that high quality of PANI nanofibers can be obtained easily in hydrochloric acid, sulfuric acid, and acetic acid, especially in the sulfuric acid; infrared and ultraviolet spectra characterization showed all products were the doped PANI. Then, using complex emulsifiers, PANI was dispersed in acrylate emulsion by supersonic dispersion assisted with mechanical stirred to obtain mixed pre-emulsion, the result showed different PANI performed different dispersing stability in the pre-emulsion. More importantly, PANI-polyacrylate copolymer was prepared through multi-steps in situ emulsion polymerization using water-soluble azo (VA-044) as initiator. Experiment showed that good dispersing stability of PANI in the pre-emulsion was premise to obtain the final stable copolymer emulsion. Further, the micro-morphology and thermal property of the copolymer were studied by transmission electron microscopy, differential scanning calorimetry, and thermogravimetric analyzer. The result proved that acrylate occurred in situ polymerization on surface of PANI nanofibers, the presence of PANI increased glass transition temperature (T(g)) and thermal decomposed temperature of the copolymer. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 627-635, 2012