Characterization of mesophase pitches made from three different raw materials

doi:10.16085/j.issn.1000-6613.2017-0789

Abstract

Abstract: In order to better understand the influence of raw materials on mesophase pitch, we synthesized three kinds of mesophase pitches with different raw materials (naphthalene, coal tar, direct coal liquefaction residue DCLR), and the properties of volatile component, saturation, molecular ordering and molecular weight of the mesophase pitches were compared. The used analysis methods included polarizing optical microscope, elemental analysis, FTIR, MALDI-TOF MS, XRD, TGA and Raman spectroscopy. The results indicated that:naphthalene based mesophase pitch (AR-MP)had higher molecular weight and narrower molecular weight distribution, higher saturation, lower volatile content and less compact structure than the other two pitches. AR-MP had a more linear structure, and as a consequence, lower soft point and finely dispersed flow texture. Coal tar based mesophase pitch (CT-MP) has broader molecular weight distribution, lower saturation, higher volatile content. It had a more compact structures due to the more rigid and flat multiple-ring molecules. The CT-MP exhibited the highest soft point and the worst flow ability, which made it difficult to form flow texture. DCLR based mesophase pitch (DCLR-MP)had narrow molecular weight distribution, moderate saturation and higher regularity of molecular structure. The DCLR-MP showed highly ordered structure and high soft point but poor flow ability.

Key words: mesophase pitch, hydrocarbons, chemical analysis, saturation, distributions, molecular ordering

摘要： 为更深入地理解不同原料制备的中间相沥青的性质差别，从挥发分、饱和度、分子量分布、有序度的角度研究了以萘、煤沥青、精制煤液化沥青（DCLR）为原料的3种中间相沥青，分析手段包括偏光显微镜、元素分析、TGA、红外光谱（FTIR）、MALDI-TOF MS、XRD、拉曼。结果表明：萘系中间相沥青分子量最高且分布窄，挥发分低，饱和基团含量高，分子柔性大，平面性和规整性较差，分子堆砌紧密度较低，有序度较差，因此具有较低的软化点和广域流线型光学组织结构；煤系中间相沥青分子量较高，分布最宽，挥发分高，饱和度低，烷基侧链少，分子刚性和平面性较大，易堆积成紧密结构，因此具有较高的软化点，流动性差，较难形成流线型光学组织结构；DCLR系中间相沥青分子量低且分布窄，挥发分较高，含有一定量的饱和基团，分子具有一定的韧性，分子刚性和规整性较好，有序度高，因此流动性较差，软化点较高。

关键词: 中间相沥青, 碳氢化合物, 化学分析, 饱和度, 分布, 有序度

CLC Number:

DUAN Chunting, LIU Junqing, XU Wenqiang, LIANG Peng, ZHENG Dongfang, WANG Qiushi, SONG Huaihe. Characterization of mesophase pitches made from three different raw materials[J]. Chemical Industry and Engineering Progress, 2018, 37(01): 189-194.

段春婷, 刘均庆, 徐文强, 梁朋, 郑冬芳, 王秋实, 宋怀河. 三种不同原料中间相沥青的性质表征[J]. 化工进展, 2018, 37(01): 189-194.

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