煤焦油制中温沥青的族组分及结构表征

Compositions and structure characterization of coal tar pitches prepared from different coal tar

采用溶剂抽提法、元素分析法、傅里叶红外光谱(FTIR)、核磁共振氢谱(1H-NMR)、凝胶渗透色谱法(GPC)对中温煤焦油制备的煤沥青(MCP)和高温煤焦油制备的煤沥青(HCP)组成结构进行研究。研究结果表明:MCP和HCP的平均分子式分别为C_(36.01)H_(34.56)N_(0.35)S_(0.13)O_(2.28),C_(46.90)H_(24.12)N_(0.41)S_(0.23)O_(0.54);软化点分别为77.6℃,86.2℃。MCP的族组成:庚烷可溶物17.34%,庚烷不溶甲苯可溶物66.94%,喹啉不溶物含量为0.95%。HCP的族组成:庚烷可溶物16.86%,庚烷不溶甲苯可溶物39.97%,喹啉不溶物含量为11.89%。与HCP相比,MCP中脂肪侧链、环烷结构较多,芳构化程度较低。采用改进的Brown-Lander模型计算分子平均结构参数,推测出两种煤沥青的平均分子结构。根据研究结果对MCP的利用提出相应的建议。

The characters of molecular structures of coal-tar pitches from different coal tar, medium coal tar pitch （MCP, prepared from medium temperature coal tar） and high coal tar pitch （HCP, prepared from high temperature coal tar）, are analyzed using solvent extraction, elemental analysis, Fourier infrared spectrum （IR）, nuclear magnetic resonance hydrogen spectrum （1H-NMR） and gel permeation chromatography （GPC）. The results indicate that the average molecular formulas of MCP and HCP are C36.01H34.56N0.35S0.13O2.28 and C46.90H24.12N0.41S0.23O0.54, and their soft points are 77.6 ℃ and 86.2 ℃, respectively. In MCP, its group composition consists of 17.34% heptane soluble, 66.94% heptane insoluble but toluene soluble and 0.95% quinoline insoluble fractions. Composition analysis of HCP indicates that the contents of heptane soluble, and heptane insoluble but toluene soluble fractions are 16.86% and 39.97%, respectively, and quinoline insoluble matter is 11.89%. In comparison with HCP, MCP possesses lower aromatization, more alkyl and naphthenic groups. Their average structures are deduced by improved Brown-Lander model. According to above results, corresponding suggestions on the use of MCP are proposed.