Author, Institution: Lukas Jasiūnas, Kaunas University of Technology
Science area, field of science: Technological Sciences, Chemical Engineering, T005
Scientific Supervisor: Assoc. Prof. Dr. Linas Miknius (Kaunas University of Technology, Technological Sciences, Chemical Engineering, T 005)
Dissertation Defence Board of Chemical Engineering Scientific Field:
Prof. Dr. Raimundas Šiaučiūnas (Kaunas University of Technology, Technological Sciences, Chemical Engineering, T 005) – chairman
Prof. Dr. T. Richard Hull (University of Central Lancashire, UK, Natural Sciences, Chemistry, N003)
Prof. Dr. Vytautas Mickevičius (Kaunas University of Technology, Technological Sciences, Chemical Engineering, T 005)
Dr. Birutė Sapijanskaitė-Banevič (Kaunas University of Technology, Technological Sciences, Chemical Engineering, T 005)
Dr. Nerijus Striūgas (Lithuanian Energy Institute, Technological Sciences, Energetics and Power Engineering, T006).
The doctoral dissertation is available at the library of Kaunas University of Technology (K. Donelaičio g. 20, Kaunas).
Polyurethane is a group of highly versatile polymers that are still largely produced using petroleum feedstocks. Typically, polyurethane is synthesized via reactions between polyols and polyfunctional isocyanates. Polyether and polyester polyols are widely used in production. Solvothermal liquefaction is a complex thermochemical process involving a number of simultaneous and competing solvolysis reactions that decompose chemical bonds in biomass under mild to moderate conditions when under homogeneous catalysis. Depending on the starting material, the biopolyols produced using this technology are rich in aromatic and aliphatic compounds with hydroxy groups, which are generally highly reactive and suitable for substituting petrochemicals in the production of polyurethane products. In this work, the liquefaction of three industrial biomass by-products abundant in Lithuania was investigated. The use of such wastes, residues and by-products could bring technologically advanced biomass industries closer to the resource-efficient concept of biorefining and the principles of circular economy. The biopolyols produced by crude glycerol-mediated solvothermal liquefaction technology in this study have been successfully used in the synthesis of high biomass fraction rigid polyurethane foams and adhesives using commercial isocyanates and polymerization additives. The mechanical, stability, toxicity properties and the potential to recycle these end-use products were determined.