The utilisation of bio-platform molecules in the green synthesis of renewable surfactants

Biomass utilisation for synthesis of renewable surfactants has many advantages. The development of alternatives to petrochemically derived products is key, as well as reduction in waste sent to landfill. This thesis focused on two surfactant types and took two approaches towards improving their green credentials. The first investigation aimed at reducing the environmental impact of the synthesis of existing surfactants, alkyl polyglucosides. Zeolites were used as green catalysts to improve product separation and enable catalyst reuse. The key properties of the zeolites were identified as pore size and Lewis acid site strength and density enabling further optimisation to be carried out. Levoglucosan, a glucose-based anhydrosugar, was used as an alternative starting material; the acetal ring improved reaction rate and stereoselectivity compared to the current synthesis from glucose. The second investigation created a range of novel surfactants with potential as drop-in replacements for current surfactants. A bio-derived platform molecule, was used in an environmentally friendly synthesis of surfactants; they were tested for surface activity and critical micelle concentration against the market standards. These compounds were shown to have higher surface activities than the equivalents, indicating they would make more efficient surfactants. In addition, they exhibited lower critical micelle concentration values meaning the replacements could be employed in smaller amounts in formulations, reducing economic along with environmental impact. The use of waste biomass, specifically waste paper, was also investigated to source levoglucosan, for alkyl polyglucoside synthesis. Microwave pyrolysis was tested on waste paper and shown to successfully produce levoglucosan in short reaction times; chemical production from this waste stream is a higher value alternative to recycling. The work detailed within highlighted how a whole process approach is key for future development and that petrochemical depletion does not have to be detrimental to the chemical industry.