Lignin Modification and its Application in Polymeric Materials

Abstract

Polymer materials are widely used in modern industry and life, and their performance and functional requirements are constantly increasing. Lignin, as a rich renewable resource in nature, a byproduct of the pulp and paper making and bioenzymatic processes, is a natural polymer material with good stability, and mechanical and chemical properties. Therefore, the application of lignin in polymer materials can improve the strength, stiffness, heat resistance, weather resistance and chemical resistance of the materials, providing a new way of application of polymer materials. However, the structure and chemical properties of lignin isolated during industrial production have changed considerably, and its use as a polymer is associated with problems of dispersion and poor compatibility, so it is necessary to modify lignin to improve compatibility with natural or synthetic polymers and to expand the range of lignin applications. Starting from the structure and properties of lignin, this paper explores a variety of lignin material modification methods, such as chemical reactions and physical blending to compound lignin with phenolic resins, polyurethane, polyolefins and other materials. Applications of lignin composite functional materials in new functional materials, energy storage materials, environmental protection and medicine are also presented, which are of great importance in promoting high performance and sustainable development of lignin materials.