The degradation and prestabilization of acrylonitrile copolymers

The degradation and prestabilization of polyacrylonitrile (PAN) were investigated with differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The initial temperature, initial loss-weight temperatures, and loss-weight were significantly lowered when ammonium itaconate (AIA) was used as comonomer. One exothermal peak of PAN (homopolymer) was shown in the DSC curves, while there were four exothermal peaks of poly(AN-AIA). FTIR spectra results confirm the degradation process of NH groups. During the heating process, NH groups (3030 cm−1) were changed into NH (2955 cm−1) and then NH groups (2920 cm−1). The dissociated H+ could initiate the cyclization reactions of CN companied with heat released. The effect of ammonia on degradation and prestabilization of PAN was also studied. It was found that ammonia could accelerate prestabilization of acrylic precursors. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

[1]  Kalim Deshmukh,et al.  Influence of γ irradiation on the properties of polyacrylonitrile films , 2008 .

[2]  C. R. Nair,et al.  Viscoelastic properties of polyacrylonitrile terpolymers during thermo‐oxidative stabilization (cyclization) , 2008 .

[3]  J. Simitzis,et al.  Correlation of chemical shrinkage of polyacrylonitrile fibres with kinetics of cyclization , 2008 .

[4]  Chengguo Wang,et al.  Acrylonitrile/ammonium itaconate aqueous deposited copolymerization , 2006 .

[5]  Chengguo Wang,et al.  Degradation of acrylonitrile–ammonium itaconate copolymers , 2005 .

[6]  J. Simitzis,et al.  Thermomechanical behaviour of poly[acrylonitrile‐co‐(methyl acrylate)] fibres oxidatively treated at temperatures up to 180 °C , 2005 .

[7]  K. Sen,et al.  Thermal behavior of drawn acrylic fibers , 2003 .

[8]  Chengguo Wang,et al.  Determination of the reactivity ratios for acrylonitrile/N‐vinylpyrrolidone copolymerization systems , 2003 .

[9]  C. R. Nair,et al.  Cyclization reaction in poly(acrylonitrile/itaconic acid) copolymer: An isothermal differential scanning calorimetry kinetic study , 2003 .

[10]  Liu Jie,et al.  Evolution of structure and properties of PAN precursors during their conversion to carbon fibers , 2003 .

[11]  A. Ogale,et al.  UV stabilization route for melt-processible PAN-based carbon fibers , 2003 .

[12]  C. Soykan,et al.  Synthesis and characterization of phenacyl methacrylate – acrylonitrile copolymers and determination of monomer reactivity ratios , 2000 .

[13]  Charles A. Wilkie,et al.  The thermal degradation of acrylonitrile-butadiene-styrene terpolymei as studied by TGA/FTIR , 1995 .

[14]  G. Bhat,et al.  Rapid stabilization of acrylic fibers using ammonia: Effect on structure and morphology , 1993 .

[15]  P. Mukherjee,et al.  The relation between the molecular weight and intrinsic viscosity of polyacrylonitrile , 1978 .