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Pyrolytic Modification of Heavy Coal Tar by Multi-Polymer Blending: Preparation of Ordered Carbonaceous Mesophase

Authors :
Lei Zhang
Chunjiang Liu
Yang Jia
Yidan Mu
Yao Yan
Pengcheng Huang
Source :
Polymers, Vol 16, Iss 1, p 161 (2024)
Publication Year :
2024
Publisher :
MDPI AG, 2024.

Abstract

In order to achieve the high-value utilization of heavy tar for the production of enhanced-performance graphite foam carbon, the carbon mesophase was ready from the heavy component of low-temperature coal tar, and the coal tar was modified by styrene-butadiene-styrene (SBS), polyethylene (PE) and ethylene-vinyl-acetate (EVA) copolymers. The order degree of the carbonite mesophase was analyzed using a polarizing microscope test, Fourier transform infrared spectroscopy and X-ray diffraction to screen out the most suitable copolymer type and addition amount. Furthermore, the mechanism of modification by this copolymer was analyzed. The results showed that adding SBS, PE and EVA to coal tar would affect the order of carbonaceous mesophase; however, at an addition rate of 10.0 wt.%, the linear-structure SBS copolymer with a styrene/butadiene ratio (S/B) of 30/70 exhibited the optimal degree of ordering in the carbonaceous mesophase. Its foam carbon prepared by polymer modification is the only one that forms a graphitized structure, with d002 of 0.3430 nm, and the maximum values of Lc and La are 3.54 nm and 2.22 nm, respectively. This is because, under elevated pressure and high-temperature conditions, SBS underwent chain scission, releasing a more significant number of methyl and other free radicals that interacted with the coal tar constituents. As a result, it reduced the affinity density of heavy coal tar molecules, enhanced fluidity, promoted the stacking of condensed aromatic hydrocarbons and increased the content of soluble carbonaceous mesophase, ultimately leading to a more favorable alignment of the carbonaceous mesophase.

Details

Language :
English
ISSN :
20734360
Volume :
16
Issue :
1
Database :
Directory of Open Access Journals
Journal :
Polymers
Publication Type :
Academic Journal
Accession number :
edsdoj.396b72415d3647d79f59bd7792aa6daa
Document Type :
article
Full Text :
https://doi.org/10.3390/polym16010161