Rauma Repola Oy

Johannes Turunen

Jan-Erik Sterholm

Jarl Johan Lindberg

J Johan Lindberg

Ermo Kaila

Kalle Levon

Bo Hortling

Anita Kinanen

A polymer that has been made of lignen and that contains sulphur, and into which a compound that activates the conductivity, such as iodine or ferric chloride, has been doped. The doped lignin polymer has properties of a semiconductor.

Doped lignin polymer

This invention relates to a three-dimensional, aromatic, sulfur-containing polymer based on lignin. The polymer is characterized in that it is amorphous, practically insoluble in water and conventional organic solvents; it contains thioether bonds and possibly sulfoxide and/or sulfone groups formed by oxidizing of thioether bonds, and possibly carbon-carbon bonds between aromatic rings and/or side chains and possibly other bonds typical to lignin, depending on reaction conditions. Its thermostability is at least 200.degree. C.; and it has been obtained from lignin which is dissolved or undissolved, chlorinated or unchlorinated, purified or containing other components of spent pulp liquor, by heating at about 160.degree.-350.degree. C., preferably in an atmosphere substantially of nitrogen and/or water vapor, for a time sufficient to form the polymer, with sulfur and/or inorganic or organic sulfur compounds so that degradation products of lignin, containing aromatic rings, or corresponding aromatic compounds, with an activating substituent have possibly been added.

Polymer made of lignin, and method for making it

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Rauma, Finland

Johannes Turunen