Rigid Polyurethane Foams Obtained from Tall Oil and Filled with Natural Fibers: Application as a Support for Immobilization of Lignin-Degrading Microorganisms

The forest biomass represents an abundant, renewable, non-food competition, and low-cost resource that can play an alternative role to petro-resources. The first topic of the research activity is focused on the use of wood and a pulp mill by-product—tall oil —as raw materials for the production of rigid polyurethane foams. The maximum content of the renewable resource in ready foams is 26%. By using biopolymers as a matrix, a natural way is to reinforce them with natural fibers. Further advantages are significant weight and cost savings and, at the same time, replacement of petrochemical raw materials. Three different natural fibers (cellulose, wood, and modified cellulose) were tested as a filler of foams. Rigid polyurethane foams was used as biomass support particles for immobilization of microorganisms. Suspension cultures of the organism with biomass support particles can promote the adhesion of cells to the porous matrix surface, and subsequently the cells become immobilized during the cultivation. This method for cell immobilization has a great potential for enhancing the production of proteins or chemicals in culture supernatants. The presence of natural fibers in the matrix promotes the enzyme production because the material not only functions as an attachment place but also supplies some nutrients to the microorganism and induces the production of ligninolytic enzymes. This paper discusses the studies into the use of tall oil as a renewable source in rigid polyurethane foam productio