Activated lignin intermediates for preparation of plant fibre reinforced composites

摘要

An intermediate product for the preparation of polymers from lignin derivatives obtained from the cellulose industry is prepared by treating the lignin derivative with a phenol-oxidising enzyme in the presence of an oxidising agent. The lignin derivatives are subjected to enzyme treatment for more than 3 hours in the presence of air, or enzyme treatment is carried out for 10 minutes or longer whilst passing air or oxygen through the reaction medium. A chemical oxidising agent is used in combination with the enzyme treatment. The use of these products for the preparation of polymers from lignin derivatives obtained from the cellulose industry is also claimed. Lignin sulphonate or kraft lignin is used as the lignin derivative. Phenol-oxidase, laccase or similar enzymes are used to treat the lignin derivative. Enzyme treatment in the presence of air is carried out for longer than 15 hours, whilst enzyme treatment in which (preferably compressed) air or oxygen is passed through the reaction medium lasts longer than 30 minutes.