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Title: Synthesis and characterisation of hypercrosslinked polymer microparticles and their functionalised derivatives
Author: Abdullah, Norhayati
Awarding Body: University of Strathclyde
Current Institution: University of Strathclyde
Date of Award: 2013
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High specific surface area, microporous polymer particles were prepared successfully by using gel-type precursor particles, derived from non-aqueous dispersion (NAD) polymerisations of monomers in ethanol, in hypercrosslinking reactions. The precursor particles (containing 1 wt% of crosslinker) were close to monodisperse, spherical, had relatively narrow size distributions (~3-4μm), and were isolated in high yields (~90%) when a 'delayed addition' methodology was applied. Such particles were essentially non-porous in the dry state, having only a very low nominal specific surface area (~2 m2/g). NAD polymers with pendent chloromethyl groups were treated with FeCl3 in 1,2-dichloroethane (DCE) at 80 °C. Hypercrosslinked particles with remarkably high specific surface areas (~1600 m2/g) were isolated successfully, even although the quality of the particles was reduced upon hypercrosslinking. As an alternative hypercrosslinking strategy, gel-type NAD precursors were treated with a low level of FeCl3 in a non-swelling solvent in order to stabilise the spherical particles prior to exhaustive hypercrosslinking. Through this approach, high quality hypercrosslinked particles with narrow particles size distributions were successfully obtained. Polymers with high specific surface areas (up to ~1300 m2/g) were prepared in this manner and the specific surface areas could be tuned depending upon the chlorine content of the swellable precursors prior to the exhaustive hypercrosslinking step. The hypercrosslinked particles then were functionalised in such a way as to give strong cation-exchange (SCX) resins and strong anion-exchange (SAX) resins. For the SCX resins, satisfactory ion-exchange capacities (IECs) were obtained by treating the polymers with concentrated sulfuric acid as a sulfonating agent. In parallel with this work, SAX resins were prepared by treatment of the chloromethyl-containing polymers with dimethybutylamine as an aminating agent. The IEC ofmaterials could be tuned depending on the level of chlorine present in the hypercrosslinked polymers.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available