High Frequency Energy Losses in Solutions Containing Macromolecules

Abstract

There is described a quantitative thermal method for measuring the loss factor of solutions containing polar molecules. By making use of the Debye dipole theory for both parts of the complex dielectric constant, it is found that normal lignin is fairly homogeneous and has a molecular weight of approximately 3900 and a shape factor of 8. The ω-hydroxydecanoic acid polymers show internal rotation of the polar groups in solution, whereas methyl methacrylate linear polymers appear to have less, but still appreciable, internal group motions.

Physicochemical Studies of Ligninsulphonates: I. Preparation and Properties of Fractionated Samples

“…Nevertheless it is interesting t o note that some investigators (3,13,20,29) have found that lignin preparations isolated under mild conditions have molecular weights not lower than 3500 t o 4000 which correspond well to the lower limit of the data presented here. According t o Gralen (13) there is some indication that lignins with degrees of polymerization corresponding t o the molecular weights 4000 and 8000 are the most stable.…”

Physico-Chemical Characterization of a Fractionated Kraft Lignin

“…Through the years, a variety of different analytic techniques, more or less successful, have been applied to determine solution properties, like molecular weight distributions and sometimes also diffusion coefficients of lignin samples (Favis et al 1981(Favis et al , 1983aConner 1941;Glasser et al 1993;Connors et al 1980;Mlynár and Sarkanen 1996;Buchholz et al 1992;Li et al 1996;Woerner and McCarthy 1988). The techniques employed, are various kinds of chromatographic methods, but ultracentrifuge sedimentation and ultrafiltration techniques have also been applied.…”