The determination of the molecular weight and molecular weight distribution of dehydrogenase polymers of coniferyl alcohol and lignins

✍ Scribed by Soundararajan, T. N. ;Wayman, Morris

• Publisher: Wiley (John Wiley & Sons)
• Year: 2007
• Weight: 546 KB
• Volume: 30
• Category: Article
• ISSN: 0449-2994
• DOI: 10.1002/polc.5070300156

✦ Synopsis

Abstract

This paper describes experiments aimed at the development of a convenient method of determining the molecular weight and the molecular weight distribution of lignins and lignin‐like polymers. As a model, a polymer of coniferyl alcohol prepared by enzymatic dehydrogenation was fractionated on columns of Sephadex G 75, G 100 and a mixture of G 75, G 100 and G 200 of equal volumes swollen in dimethyl sulphoxide. The columns were calibrated by means of sharp fractions obtained by preparative fractionation characterized independently by sedimentation equilibrium ultracentrifugation. From the elution curve of the sample and the calibration curve the molecular weight and its distribution were calculated. The assumption that the system predicts the molecular weight and its distribution correctly was tested by running a sample whose molecular weight distribution was known by ultracentrifugation. The distribution calculated from the gel column chromatograph was found to coincide with that obtained by ultracentrifugation. The molecular weights and their distributions obtained on milled wood lignin samples by this method appear to be reasonable.