Development and Utilization of Bio-based Platform Chemicals for Renewable Materials

Abstract

In the progression of modern society, the inevitable exhaustion of fossil resources becomes an increasingly concerning matter. These resources are not only the cornerstone of the energy production of the world, but also the precursor for many important platform chemicals used in the plastics industry. With a disappearance of fossil resources on the horizon, alternatives have to be developed, for example, tackling the energy crisis through revolutions in the field of renewable energy. However, regarding platform chemicals, a new and sustainable source has to be used, such as biomass. One of the larger challenges when employing biomass as a renewable resource, is the natural high abundance of oxygen compared to the petrol-based precursors, which calls for the development of catalytic reactions capable of oxygen removal, in order to obtain useful platform chemicals mimicking those used today. The first part of this thesis concerns development of two of these reactions; the deoxydehydration and the hydrodeoxygenation reactions. The deoxydehydration reaction is studied both using vanadium and rhenium catalysts, whereas the hydrodeoxygenation reaction is preformed using a molybdenum catalyst. The studies revolve around examination of the reactions by applying the computational method Density Functional Theory, which allows for elucidation of the intrinsic mechanism of the reactions. This leads to discoveries of new types of mechanisms for both reactions, explaining differences in reactivity compared to what has previously been observed in literature for similar catalytic systems. An example of utilization of these reactions is the production of allyl alcohol, which can be obtained from deoxydehydration of glycerol – a compound yielded as a side-product from the bio-diesel industry. The second part of the thesis focuses on the utilization of bio-based platform chemicals for synthesis of novel thermoset polymer materials. Common ground for all of these studies is the diallyl furan-2,5-dicarboxylate monomer, which is tested through a plethora of different crosslinking techniques. This monomer is of high interest due to being derived from allyl alcohol and the bio-based building block 2,5-furandicarboxylic acid, the latter showing application as a replacement for phthalates. In the studies, this new monomer is tested in various ways; firstly through UV-initiated crosslinking to thiol-ene networks, then synthesis of larger prepolymeric structures for crosslinking, and finally expansion into epoxy networks through copolymerization with epoxidized fatty acid esters. These studies lead to various new materials, along with new methods for determinations of molecular weights of branched polymer systems, by examining the intrinsic growth patterns of hyperbranched polyester systems. With this thesis, foundation for further development of methods for production of bio-based platform chemicals have been developed along with new methods for the utilization of these chemicals for renewable materials. These materials represents a plausible replacement of their petrol-based analogues, hereby laying parts of the groundwork for a more sustainable and renewable future.