In Situ Fourier-Transform Infrared Spectra Analysis of Hydrogen Bond in Polypropylene/Chlorinated Polypropylene/Polyaniline Composite

摘要

The previous studies suggest that hydrogen bond between chlorinated polypropylene (CPP) and poly-aniline (PANI) plays a prominent role in the decision of polypropylene/CPP/PANI composites' electric property. In situ Fourier-transform infrared spectra were employed to detect and identify the relationship between the hydrogen bond and the temperature. Two kinds of hydrogen bond were carefully studied in the nitrogen-hydrogen bond (N H) stretching, sulfur-oxygen double bond (S=0) stretching, and carbon-chlorine bond (C桟I) stretching regions, using an iterative least-squares computer program to obtain the best fit of spectra. The ratio of absorptivity coefficients and the mole fraction of the 'free' and two kinds of H-bonded N H were calculated. There exists an apparent turning point in the curves of the relationship between the fraction of two kinds of H-bonded N H and temperature. This phenomenon also exists in the S=0 stretching region, and the turning point is at about 60 C. The mole fraction of H-bonded C桟I decreases, and that of 'free' C桟I increases with increasing temperature. The enthalpy gap between the H-bonded N-H 0=S and the H-bonded N-H CI=C dissociation was also obtained as 23.2 KJ/mol.