水性中间相沥青的制备研究

STUDY OF PREPARATION OF AQUA-MESOPHASE PITCH

以煤焦油沥青为原料 ,以浓硫酸和浓硝酸为氧化剂 ,可得到易溶于碱性水溶液的水性中间相沥青。详细考察了沥青氧化条件对水性中间相沥青收率的影响 ,以及水性中间相沥青的元素和官能团组成。结果发现 ,反应温度、浓硫酸和浓硝酸的比例对水性中间相沥青收率影响存在一优化值 ,而反应时间、浓硫酸和浓硝酸的用量对水性中间相沥青收率先是线性的 ,当达到一定值后水性中间相沥青的收率基本恒定。水性中间相沥青的组成是复杂的 ,根据其中化合物含氧官能团的数量和性质 ,它们可分别在不同pH值条件下制备而得。

The preparation of aqua mesophase pitch (AMP) was investigated by oxidation of coal tar pitch with mixtures of concentrated sulfuric acid and nitric acid. Oxidation conditions (temperature, concentration of nitric acid in the mixed acids, oxidation time and amount of mixture of acids used) were studied in detail for their effects on the yields of AMP at different pH. It was found through FT IR spectroscopy and chemical analysis that solubility of the AMP in alkaline is a consequence of the attachment of hydrophilic groups ( OH, COOH, SO 3H, NO 2) to the pitch molecule. Oxidation temperature and content of nitric acid in mixed acids influence the yields of AMP with optimal values. AMP yields increase with increase of oxidation time or amount of mixed acids up to certain values, after which AMP yields are almost constant. The yield and composition of AMPs precipitated at different pH in a step wise manner are different.