对甲基苯甲醛改性煤沥青的原位成纤机理研究

The in-situ formation of fibrils in coal tar pitch modified with p-methyl benzaldehyde

以对甲基苯甲醛为改性剂,在对甲苯磺酸的作用下对煤沥青进行了改性,并对改性后煤沥青的原位成纤机制进行研究。采用FT IR和1H NMR对改性煤沥青的化学结构进行分析,采用SEM对改性煤沥青的原位成纤形态进行观察。研究表明,对甲基苯甲醛能够与煤沥青发生亲电取代反应,使煤沥青中的活性小分子交联形成大分子。此外,改性煤沥青中出现很多微纤,随着改性时间的增加,纤维直径越来越大,最后形成分布均匀且线性很好的纤维束。因此,经过对甲基苯甲醛改性后的煤沥青有望成为优质的炭材料基体前躯体。

Modification of coal tar pitch with p-methyl benzaldehyde in the presence of p-toluene sulfonic acid and the in-situ fibrillating mechanism of the modified coal tar pitch were investigated by FT-IR and H-1-NMR spectra and SEM. Results show that coal tar pitch undergoes an electrophilic substitution reaction with p-methyl benzaldehyde, transforming the reactive small molecules in the coal tar pitch to macromolecules through methylene functional groups. Moreover, there are many microfibers; in the modified coal tar pitch, which grow with modification time, and eventually form linear bundles with a uniform distribution. The modified coal tar pitch is a promising precursor for carbons.