中温沥青族组成分析及其对中间相沥青结构的影响

Analysis of medium temperature coal tar pitch group composition and its effect on the structure of mesophase pitch

以甲苯-吡啶、正庚烷-四氢呋喃为溶剂,采用索氏抽提分离中温沥青(ZCTP)的族组分并解析其组成与结构。结果表明,与ZCTP相比,甲苯不溶-吡啶可溶物(TI-PS)和正庚烷不溶-四氢呋喃可溶物(HI-THFS)的热稳定性更高,残炭率增至56.95%和47.63%,失重量分别减小41.51%和28.85%;此外,TI-PS和HI-THFS的C=C含量分别比ZCTP高6.69%和3.26%,为75.57%和73.14%,吡啶氮含量分别提升约16和8个百分点。以TI-PS和HI-THFS为原料分别制得中间相沥青M-TI-PS和M-HI-THFS。其中,M-HI-THFS以中小区域型为主,并伴有部分细镶嵌结构,光学各向异性含量较低;M-TIPS光学各向异性含量约为80%,且形成了广域型光学织构;然而ZCTP难以形成稳定的区域型光学织构,只能形成马赛克型光学织构。

Medium temperature coal tar pitch(ZCTP)was separated by Soxhlet extraction using toluene-pyridine and n-heptane-tetrahydrofuran as solvents to obtain the group components.Then,their composition and structure were analyzed.The results show that,in comparison with ZCTP,toluene-insoluble pyridine soluble(TI-PS)and nheptane-insoluble tetrahydrofuran soluble(HI-THFS)are more thermally stable,exhibiting a decrease weight loss of 41.51%and 28.85%and an increase residual carbon rate of 56.95%and 47.63%,respectively.In addition,the C=C contents of TI-PS and HI-THFS are 6.69%and 3.26%higher than that of ZTCP,reaching 75.57%and 73.14%,and the pyridine nitrogen contents of TI-PS and HI-THFS increase about 16 and 8 percentage points.Both TI-PS and HI-THFS were used to prepare mesophase pitch.It is found that M-HI-THFS is mainly consisted of small and medium area type with some fine mosaic structure and low optical anisotropy content.While M-TI-PS has about 80%optical anisotropy content and displays a wide range of optical weave.However,it is difficult for ZCTP to form a stable regional optical fabric structure,just exhibiting a mosaic optical fabric.