Thomas J. Farmer

Opportunities for Bio-Based Solvents Created as Petrochemical and Fuel Products Transition towards Renewable Resources

The global bio-based chemical market is growing in size and importance. Bio-based solvents such as glycerol and 2-methyltetrahydrofuran are often discussed as important introductions to the conventional repertoire of solvents. However adoption of new innovations by industry is typically slow. Therefore it might be anticipated that neoteric solvent systems (e.g., ionic liquids) will remain niche, while renewable routes to historically established solvents will continue to grow in importance. This review discusses bio-based solvents from the perspective of their production, identifying suitable feedstocks, platform molecules, and relevant product streams for the sustainable manufacturing of conventional solvents.

Circular economy design considerations for research and process development in the chemical sciences

A circular economy will look to chemistry to provide the basis of innovative products, made from renewable feedstocks and designed to be reused, recycled, or the feedstock renewed through natural processes. The substances that products are made of will increasingly be treated as a resource equal to the raw materials, and not just disposed of. This perspective discusses the role of chemists in a world without waste.

Synthesis of Unsaturated Polyester Resins from Various Bio-Derived Platform Molecules

Utilisation of bio-derived platform molecules in polymer synthesis has advantages which are, broadly, twofold; to digress from crude oil dependence of the polymer industry and secondly to reduce the environmental impact of the polymer synthesis through the inherent functionality of the bio-derived platform molecules. Bulk polymerisation of bio-derived unsaturated di-acids has been employed to produce unsaturated polyester (UPEs) which have been analysed by GPC, TGA, DSC and NMR spectroscopy, advancing on the analysis previously reported. UPEs from the diesters of itaconic, succinic, and fumaric acids were successfully synthesised with various diols and polyols to afford resins of MN 480–477,000 and Tg of −30.1 to −16.6 °C with solubilities differing based on starting monomers. This range of properties allows for many applications and importantly due to the surviving Michael acceptor moieties, solubility and cross-linking can be specifically tailored, post polymerisation, to the desired function. An improved synthesis of itaconate and succinate co-polymers, via the initial formation of an itaconate bis-diol, is also demonstrated for the first time, resulting in significantly improved itaconate incorporation.

Microwave heating for rapid conversion of sugars and polysaccharides to 5-chloromethyl furfural

A range of carbohydrates has been rapidly and selectively converted to 5-chloromethyl furfural using microwave heating in a biphasic reaction system with a range of organic solvents. Fructose and inulin were especially effective for production of this valuable bio-platform molecule, with yields of >70% obtained in 15 minutes under microwave heating. Yields from cellulose were dramatically increased with ball mill pre-treatment, this being associated with a reduction in polysaccharide crystallinity.

A new perspective in bio-refining: levoglucosenone and cleaner lignin from waste biorefinery hydrolysis lignin by selective conversion of residual saccharides

An unexpected opportunity is reported to improve the sustainability of biorefineries whereby 8 wt% levoglucosenone (LGE) can be derived from unconverted saccharides in a lignin-rich biorefinery waste stream in a highly selective fashion (>90%). Additionally, in the process a purer lignin is obtained which can be used for further processing or materials applications. LGE is a valuable and versatile product with a plethora of applications.

Post-polymerisation modification of bio-derived unsaturated polyester resins via Michael additions of 1,3-dicarbonyls

Post-polymerisation modification of α,β-unsaturated polyesters (UPEs) is useful to deliver polymers with tuneable properties and applications different from their parent backbone. Bio-derivable itaconate unsaturated polyesters, with a range of co-monomers, were modified via a heterogeneously catalysed microwave-assisted Michael addition of pendants, acetylacetone (Hacac) and dimethyl malonate (DMM), to the polymer backbones with very short reaction times. Differential scanning calorimetry analysis showed an increase in the glass-transition temperatures of most of the saturated polyesters considered. Solubility and complexation studies demonstrated metal chelating abilities of the acetylacetone pendant can be retained, even following tethering to a polyester backbone. Additionally, it is demonstrated for the first time that Michael addition with Hacac and DMM can be used to reverse Ordelt saturation, an unwanted side-reaction in the synthesis of UPEs.

2,2,5,5-Tetramethyltetrahydrofuran (TMTHF): a non-polar, non-peroxide forming ether replacement for hazardous hydrocarbon solvents

An inherently non-peroxide forming ether solvent, 2,2,5,5-tetramethyltetrahydrofuran (2,2,5,5-tetramethyloxolane), has been synthesized from readily available and potentially renewable feedstocks, and its solvation properties have been tested. Unlike traditional ethers, its absence of a proton at the alpha-position to the oxygen of the ether eliminates the potential to form hazardous peroxides. Additionally, this unusual structure leads to lower basicity compared with many traditional ethers, due to the concealment of the ethereal oxygen by four bulky methyl groups at the alpha-position. As such, this molecule exhibits similar solvent properties to common hydrocarbon solvents, particularly toluene. Its solvent properties have been proved by testing its performance in Fischer esterification, amidation and Grignard reactions. TMTHFs differences from traditional ethers is further demonstrated by its ability to produce high molecular weight radical-initiated polymers for use as pressure-sensitive adhesives.

Recirculation: A New Concept to Drive Innovation in Sustainable Product Design for Bio-Based Products

Bio-based products are made from renewable materials, offering a promising basis for the production of sustainable chemicals, materials, and more complex articles. However, biomass is not a limitless resource or one without environmental and social impacts. Therefore, while it is important to use biomass and grow a bio-based economy, displacing the unsustainable petroleum basis of energy and chemical production, any resource must be used effectively to reduce waste. Standards have been developed to support the bio-based product market in order to achieve this aim. However, the design of bio-based products has not received the same level of attention. Reported here are the first steps towards the development of a framework of understanding which connects product design to resource efficiency. Research and development scientists and engineers are encouraged to think beyond simple functionality and associate value to the potential of materials in their primary use and beyond.

Ring opening metathesis polymerisation of a new bio-derived monomer from itaconic anhydride and furfuryl alcohol

A new oxa-norbornene bio-based lactone obtained from the 100% atom economic reaction of furfuryl alcohol and itaconic anhydride via a tandem Diels–Alder addition and lactonisation is presented. Esterification of the resulting acid gives a monomer for the production of a bio-based polymer with low polydispersity and well controlled molecular weight via ring-opening metathesis polymerisation (ROMP).

CHAPTER 1:Elemental Sustainability and the Importance of Scarce Element Recovery

A growing movement towards the development of “low carbon technologies” and an increased demand for consumer electronics are contributing towards a resource deficit. Many of these technologies require rare and precious metals for their production and use. The reserves of these elements are being depleted at a rapid rate, but they are not “running out” or being destroyed. These unique elements are being quickly dispersed throughout our environment, making their recapture both highly challenging and costly. As such, it is essential to develop new sustainable routes and strategies for the recovery and reuse of these elements. This chapter discusses the issues relating to those elements regarded as being “critical” in terms of having significant international supply risk issues and which are also vital to a nation’s economy (or company’s business). The importance of adopting a sustainable holistic approach to the extraction, processing, use and recovery is highlighted as being vital in ensuring a sustainable long‐term supply of all elements.