对甲基苯甲醛改性煤沥青的工艺研究

On Technique for Modification of Coal Tar Pitch with 4-Methyl Benzaldehyde

以对甲基苯甲醛(4-methyl benzaldehyde,简称4-MB)为改性剂,在对甲苯磺酸(PTS)的作用下对煤沥青(coal tar pitch)进行了改性。采用偏光显微镜研究了4-MB改性煤沥青的光学组织;考察了4-MB用量,反应温度和反应时间对改性沥青的软化点、密度、残炭率的影响。结果表明,在同一反应条件下,随4-MB用量的增加,改性沥青的密度、软化点、残炭率先显著提高后稍有降低。随着反应温度的提高及反应时间的延长,改性沥青的密度、软化点、残炭率先明显提高,后增加不大。可通过添加不同的4-MB用量或调节反应温度控制改性沥青的中间相小球的数量和球径的大小,从而改善得到较好的光学组织。

Modification of coal tar pitch（CTP） as carbon materials was studied using 4-methyl benzaldehyde（4-MB） as a modifier and toluene-p-sulfonic acid as a catalyst. Polarized microscope was employed to study the optical structure of pyrolyzed substances of the modified coal tar pitch. It can be concluded that reaction conditions affect the properties and microstructure of modified pitch. The results show that with the increase of doses of 4-MB, the softening point, density and carbon y.ield of modified pitch obviously increase and slightly decrease subsequently under the same reaction conditions. For the same doses of 4-MB, the softening point, density and carbon yield of modified pitch obviously increase and increase subsequently with the increase of reaction temperature and the elongationof reaction time. The optical texture of pyrolyzed substances can be improved by adding different doses of 4-MB or by adjusting the temperature to control the mesophase microbeads and their diameters.