Phosphorous three ways: polymers, monomers, and catalysts
Macdonald, Emily Kate
The existence of numerous phosphorus containing functional groups gives phosphorus chemistry its enormous breadth. The range of functional groups stems from phosphorus’ ability to vary its coordination and valance. Phosphorus containing compounds have shown applications in agriculture, biological systems and chemical warfare. High refractive index polymers are used in lenses, fingerprint recognition and optical coatings. However, often these devices rely on to the materials available. Phosphorus rich polymers have shown promise due to the high level of polarisability. A range of poly(phosphate ester)s and polyphosphonates have been synthesised and their thermal and optical properties tested. Some of the samples prepared boast the highest refractive indices for these types of compounds. Polymers synthesised via a polycondensation mechanism usually possess a high dispersity, one way to introduce control is via a ring opening polymerisation (ROP). Novel aromatic phosphonate monomers have been prepared and attempted to polymerise. Monomer, catalyst and copolymerisation scope for aliphatic phosphonate ROP has also been explored. Organocatalysts are becoming increasingly popular in ring opening polymerisation literature, one of the most popular organocatalysts is triazabicyclodecene (TBD). TBD is a dual activating catalyst as it activates both the initiator and monomer via a basic and acidic moiety respectively. Phosphates also have dual activating substituents. A range of aromatic phosphates have been successfully synthesised with varying electron withdrawing/ donating groups. These catalysts were then screened against the polymerisation of β-butyrolactone and their catalytic activity investigated.