The determination of the molecular distributions of graphite binder materials by gel permeation chromatography

Abstract

The molecular distributions of a number of furfuryl alcohol resins, coal tar pitches, coumarone-indene resins and gilsonite resins were characterised by the new technique of gel permeation chromatography (GPC). The components of the furfuryl alcohol resins ranged in mol. wt. from about 5000 down to monomer. The lower mol. wt. species were well resolved by GPC, and the degrees of conversion to higher mol. wt. polymer could easily be noted. The GPC curves of the tetrahydrofuran-soluble fractions of a series of coal tar pitches fell between 4000 and 70 or 80. The pitch fractions all had peak maximums at about 200 and tailed on the high mol. wt. sides. The coumarone-indene GPC curves varied markedly with softening points. The molecular distributions of these polymers appeared between 5000 and 70 or 80. A dependence of the coumarone-indene molecular distributions on color index was also found. The gilsonite resin molecular distributions ranged from 5000 to 70 or 80 with the peak maximums at approximately 2000.