| 摘要 |
Lignin or derivs. are first dispersed in an alkylene oxide at a low temp. so that no reaction occurs, e.g. 18-22 deg. C. The temp. is raised and the lignin reacts with the alkylene oxide. Opt. the reaction prods. can later be reacted with the same or other alkylene oxides. Pref. sulphate lignin or sulphite lignin and/or lignin sulphonate are used. The dispersing medium is one or more of the C2-C6 alkylene oxide esp. propylene oxide. In an example, propylene oxide is placed in autoclave with stirrer at room temp. Powdered sulphate lignin and sodium hydroxide are added under nitrogen. After heating to 100 deg. a further propylene oxide is added while stirring. After the reaction, the mixt. is cooled to room temp. The reaction prods. were 98% soluble in water and had a surfact tension of 39.1 mN/m. |
