Grantham Scholar Robert Matthews’ project will look for ways to synthesise plastics from sustainable sources.
Polymer plastics are some of the most widely used materials in the world today and are almost ubiquitous in the world around us. One of the most significant issues with polymers is that many of the monomers come from non-renewable fossil fuels, such as oil and natural gas. As these resources run out, it is essential that we are able to develop polymers from monomers derived from alternative sources. My project is focused on the development of a material for the catalysis of reactions to synthesise polymer building blocks from sustainable sources, such as biomass.
One such polymer derived from fossil fuels is polyethylene terephthalate (PET), which is the main polymer used to make plastic bottles. Another polymer, polyethylene furanoate (PEF), has been suggested as a possible, sustainable alternative, derived from biomass. This can be synthesised by a two-step process involving the base catalysed isomerisation of glucose to fructose, followed by an acid catalysed reaction from fructose to 5-hydroxymethylfurufural (HMF), the key building block of PEF. As well as this, other HMF derivatives include 2,5-dimethylfuran (DMF), which is a potential biofuel with greater energy content than bioethanol, and gamma-valerolactone (GVL), which is an organic biosolvent for synthetic applications, with other HMF derivatives having potential as the basis for bioderived polyurethanes and other polyesters.
Due to the synthesis of HMF involving a base catalysed reaction and an acid catalysed reaction, it is impossible to perform this reaction in a single phase in one-pot. The use of solid catalysts with separate acid and base functional groups would allow this reaction to be done in a single pot, reducing waste and the energetic cost, a process called tandem catalysis. Some catalysts have been developed for this, but all have issues, such as the used of toxic solvents and environmentally damaging reagents.
The Dawson group has developed a material, called dispersible porous polymer particles (d-PPPs), which can be dispersed in biosolvents, which could potentially be used as the basis for materials for tandem catalysis. The aim of my project is to develop a d-PPP with separate acid and base functional groups that can be dispersed in biosolvents, such as ethanol and water, for the synthesis of HMF from glucose, thus increasing the viability of the use of HMF derivatives for the replacement of fossil fuel derived plastics.