Completely isotactic polyacrylonitrile (meso/meso triad >99%) has been synthesized successfully by radiation-induced inclusion polymerization of acrylonitrile in urea canals. The long-lived nature of the growing radical species and the linear dependence of molecular weight on conversion were observed. The molecular weight distribution of product polymers was relatively narrow (<1.5). The results indicate that the dual control of the molecular weight and the tacticity for inclusion polymerization of acrylonitrile in urea canals is achieved. In addition, the effect of experimental factors of inclusion polymerization on the isotacticity of product polymers was investigated. It is found that to ensure completely isotactic polyacrylonitrile, the following conditions should be met simultaneously: (1) acrylonitrile monomers are included in urea canals totally before γ-ray irradiation, (2) the temperature at the chain propagation step is lower than −90 °C, and (3) the heat of polymerization is removed effectively.

Polyaniline (PANI)/silver composite was one-step synthesized under γ-ray irradiation. The structure of the composite was characterized by Fourier transform infrared spectroscopy, UV-Visible, and X-ray diffraction, which indicated that PANI and face-centered-cubic silver were synthesized under γ-ray irradiation. The reaction mechanism were discussed, which revealed that the PANI was formed by the reaction of aniline cation radicals formed by the reaction of aniline cation and ·OH, and Ag was formed by the reaction of Ag + and e − aq . The morphology of the composite consisted of PANI nanofibers and Ag nanoparticles, and the mechanism of the morphology formation was discussed, which revealed that the rapid mixing like polymerization process might play an important role. It was revealed that the transport behavior of the composite well fitted with the variable-range-hopping model in 80-300 K and deviated from the model below 80 K.

Abstract:The formation process and composition of the acrylonitrile/urea inclusion compounds (AN/UIC) with different aging times and AN/urea molar feed ratios are studied by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). It is suggested that DSC could be one of the helpful methods to determine the guest/host ratio and the heat of decomposition. Meanwhile, the guest/host ratio and heat of