ANALYSES OF THE SOLUBLE PRODUCTS OF YUBAR I AND TAIHEIYO COALS TREATED WITH ZINC AND BUTYL IODIDE .1.

Yubari and Taiheiyo coals were converted to hexane soluble products in high yields by the repetitive butylation using zinc and butyl iodide under mild conditions (130-degrees-C, under atmospheric pressure). The hexane soluble products were fractionated into seven fractions by col umn chromatography (CC), and the CC fractions were further separated b y gel permeation chromatography (GPC) to investigate the chemical stru cture of the solvent-soluble products and the mechanism of the coal so lubilization. The GPC fractions of both coals had high sigma(al) (degr ee of aliphatic chain substitution) and low fa (aromaticity), because of the introduction of many butyl groups to coal aromatic moieties. Th e size of aromatic rings of the GPC fractions seemed to be small, 2-3 rings for Yubari coal; these small aromatic ring size may be caused by reductive butylation. The lower aliphatic chain length (L = 2.1-2.9) of the GPC fractions, than expected from the introduction of many buty l groups (L = 4), also indicated the occurrence of reductive butylatio n. In addition, the yields (based on original coals) of the GPC fracti ons with average molecular weight below 800 were small 7.7 wt% for Yub ari coal and 17.8 wt% for Taiheiyo coal, indicating that the linkage c onnecting aromatic moieties of coal was not broken so much. These char acteristics of GPC fractions indicate that the high extractabilities o f the butylated coals with solvents are mainly caused by the reductive butylation of aromatic moieties of the colas.