The non-isothermal cyclization kinetics of amino-functionalized carbon nanotubes/polyacrylonitrile composites by in situ polymerization

The non-isothermal cyclization kinetics of amino-functionalized carbon nanotubes (amino-CNTs)/polyacrylonitrile (PAN) composites was investigated using differential scanning calorimetry (DSC) in nitrogen atmosphere. The amino-CNTs/PAN composites were prepared by in situ polymerization under ultrasonication. The X-ray diffraction analysis showed that the composites had lower degree of crystallization compared with the neat PAN homopolymer. The morphology of composites suggested that the amino-CNTs had homogeneous dispersion in the PAN matrix. The Kissinger method and Crane method were used for describing the non-isothermal cyclization reaction of the neat PAN homopolymer and the amino-CNTs/PAN composites using DSC data with different heating rates. The results showed that the addition of amino-CNTs into the neat PAN homopolymer decreased the initial temperature and the peak temperature for the cyclization reaction. The amino-CNTs/PAN composites had higher activation energy than the neat PAN homopolymer, indicating that the presence of the amino-CNTs hindered the mobility of the PAN chain segments. The n-th order for the amino-CNTs/PAN composites is more close to one than that of the neat PAN homopolymer.