| Popis: |
Although coconut chars have been used extensively as adsorbents for a century, they have not been studied spectroscopically. Consequently, infrared spectra were recorded, using FT photothermal beam deflection spectroscopy, of coconut shell heated in vacuum at various temperatures up to 800°C. The pyrolysis occurs in three stages. In the first, from room temperature to about 250–300°C, the precursor breaks down, and changes in texture. In the second stage, from about 300 to 550°C, the originally largely aliphatic mixture is converting to one which is predominantly aromatic in character. Then, above about 550°C, the material becomes increasingly polyaromatic. |
