Viscoelastic Properties and Adsorption Behaviors of Two Kinds of Pyridine Insoluble Fractions of Coal Extracts with Different Aggregated States
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- 作者：Hengfu Shui ; Zhicai Wang
- 刊名：Energy & Fuels
- 出版年：2007
- 出版时间：September 2007
- 年：2007
- 卷：21
- 期：5
- 页码：2827 - 2830
- 全文大小：74K
- 年卷期：v.21,no.5(September 2007)
- ISSN：1520-5029
文摘
Two kinds of pyridine insoluble fractions (PI) of coal extracts with different solubilities in N-methyl-2-pyrrolidinone (NMP) were characterized in this paper. PI-0 was obtained by the pyridine fractionation ofUpper Freeport coal extracts with a CS2/NMP mixed solvent (1:1 by volume), and its solubility in NMP is 53wt %. While PI-1, which was obtained by the removal of NMP and tetrabutylammonium acetate (TBAA)from a PI-0 solution in NMP containing TBAA, was almost completely soluble in NMP. Solid-state 13CNMRspectra indicated that the two PIs have the same chemical structure. The viscoelastic properties and methanoladsorption behaviors of the two PIs were measured. The dynamic viscoelasticities of the two PIs are similar,and the elastic modulus (G') of PI-1 is lower before the softening temperature than that of PI-0, suggestingthat the macromolecular network of PI-1 is looser compared to that of PI-0. The methanol sorption behaviorsof PI-0 and PI-1 are also similar, and lines curve-fitted with the Langmuir-Henry equation were in agreementwith the experimental data, suggesting that the bulk structure of the two PIs is similar. The methanol sorptionfor PI-1 is larger than that for PI-0. The constants of the Langmuir-Henry equation obtained by successivefitting for the two PIs indicated that the microporosity of PI-1 is larger than that of PI-0. The results obtainedhere suggested that the dissociation of molecular interactions is responsible for the high solubility of PI-1.