UC Davis

This Ph.D. thesis investigates the versatile applications of biomass derivatives including cellulose, the most abundant polymer in nature.

Chapter 1 provides a general introduction to the research areas covered in this thesis.

Chapter 2 explores the utility of trifluoroacetic acid (TFA) as a dispersing medium for cellulose nanocrystals (CNCs), emphasizing its distinctive solvent properties and its ability to stabilize CNC suspensions. The study demonstrates the dispersibility of native CNCs in TFA and investigates the aging of CNC-TFA suspensions, resulting in the gradual addition of trifluoroacetyl groups to the CNC surface. This method is extended to the formation of a nanocomposite with polyethylene terephthalate (PET), presenting a promising strategy for combining organic-soluble polymers with native cellulose.

Chapter 3 introduces an innovative concept involving dyes synthesized entirely from biomass-derived platform molecules, specifically 5-(chloromethyl)furfural (CMF), which can be produced directly from cellulose in a one-step reaction. This methodology circumvents the limitations associated with petrochemical-derived dyes and natural colorants. Using a furylogous malonate or furylogous cyanoacetate and biomass-derived aldehydes, the study process generates industrially relevant synthetic colorants with vibrant hues, demonstrating excellent performance and fastness on selected fabrics. The vision of achieving 100% renewable textiles, where both synthetic fibers and dyes are biobased, is discussed, constituting a transformative approach to sustainable wearables.

In Chapter 4, the focus shifts to the transformation of CMF into 2,5-diformylfuran (DFF), which is used in the synthesis of the sustainable dyes in Chapter 3, through oxidation with bismuth nitrate pentahydrate. The study spans different scales, and works toward optimizing yields and addressing challenges encountered during scale-up. Techniques such as continuous extraction, sonication, and variations in extraction solvents are employed to enhance reproducibility. Despite the progress made, further work will be necessary to give consistent yields, particularly at larger scales. Collectively, these chapters significantly contribute to the evolving landscape of sustainable materials and processes, showcasing the potential for innovative applications across diverse fields.