Effect of different itaconic acid contents of poly(acrylonitrile-co-itaconic acid)s on their carbonization behaviors at elevated temperatures

The carbonization procedure is a crucial step for polyacrylonitrile (PAN)-based precursors to be transformed into carbon materials. In this study, PAN and poly(acrylonitrile-co-itaconic acid)s (PAIs) with different contents of itaconic acid (IA) were prepared through free radical polymerization, and their carbonization behaviors were investigated at different thermal treatment temperatures. As confirmed by Fourier transform infrared spectroscopy analyses, functional groups containing heteroatoms practically disappeared above 600 °C, due to crosslinking, condensation, dehydrogenation, and gas-evolution reactions of the carbonization processes. Deconvolution of the carbon, oxygen and nitrogen peaks from X-ray photoelectron spectroscopy analyses revealed the development of ordered and doped graphitic carbons at elevated thermal treatment temperatures. The total yields of PAIs with excess amounts of IA (3 ~ 6 mol%) demonstrated a large carbon loss during the carbonization procedures. PAI with 1 ~ 2 mol% IA afforded carbon materials with a relatively high graphitic carbon content at 1200 °C, which is potentially important for electrical conductivity. Meanwhile, carbon materials prepared from PAI with 2 mol% IA at 1200 °C exhibited a relatively high content of pyridinic nitrogen, suggesting potentially superior catalytic activity. This study afforded technical guidelines on the structural elements of PAN-based precursors to prepare carbon materials with predesigned characteristics.