Metathesis Curing of Allylated Lignin and Different Plant Oils for the Preparation of Thermosetting Polymer Films with Tunable Mechanical Properties

摘要

Lignin and plant oils-two highly available renewable feedstocks-are cured via olefin metathesis to produce thermosetting polymer films with tunable mechanical properties. Therefore, an organosolv lignin, allylated in a recently described sustainable approach, is used. For the first time, unmodified plant oils are reacted with a lignin derivative. An increasing lignin content as well as an increasing amount of polyunsaturated fatty acids in the plant oil structure lead to higher Young's moduli and higher cross-linking density. Stress-strain measurements reveal ductile behavior of the prepared films. Only a lignin content over 70% leads to brittle materials. To improve the overall sustainability of this approach, dimethyl carbonate is investigated as sustainable solvent for film formation, leading to materials with similar Young's moduli and tensile strength, but lower degree of cross-linking if compared to the more volatile solvent dichloromethane.