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1. Thiol-Ene “Click” Chemistry and the Production of Porous Polymer Materials Durham E-Theses Chemical Functionalization of thiol-acrylate polyHIPEs LANGFORD, CAITLIN,ROSE How to cite: LANGFORD, CAITLIN,ROSE (2014) Chemical Functionalization of thiol-acrylate polyHIPEs, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/10762/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk Chemical Functionalization of Thiol- Acrylate polyHIPEs A thesis submitted in fulfilment of the requirements for the degree of Master of Science. Caitlin Rose Langford 2014 1 | P a g e Abstract The work described herein describes the synthesis and subsequent functionalization of thiol-acrylate emulsion templated porous polymers (polyHIPEs). Thiol-ene “click” chemistry has been employed in order to produce polyHIPEs from multifunctional thiol and acrylate monomers, and the level of residual thiol within the material determined. These residual thiols have then been used as “reactive handles” which allow for the functionalization of the thiol-acrylate polyHIPE post-polymerization. Both radical mediated thiol-ene “click” and amine catalysed Michael additions have been used in order to graft acrylates to the polymer surface, and the formation of disulphide bonds between the polymer surface and thiols has been explored. The non-crosslinking monomer pentafluorophenyl acrylate (PFPA) has also been incorporated into thiol-acrylate polyHIPEs in order to provide a route to post-polymerization functionalization. The reaction between the PFPA within the polymer network and amines occurs under mild conditions and so this has been explored as a route to the incorporation of biomolecules in the polymer network. 2 | P a g e Table of Contents Abstract ......................................................................................................................... 2 Table of Contents ........................................................................................................ 3 List of Figures .............................................................................................................. 6 List of Reaction Schemes ...................................................................................... 10 List of Tables ............................................................................................................. 12 List of Abbreviations .............................................................................................. 13 Declaration ................................................................................................................ 17 Statement of Copyright ......................................................................................... 17 Acknowledgements ................................................................................................ 18 1. Thiol-Ene “Click” Chemistry and the Production of Porous Polymer Materials ............................................................................................................ 19 1.1 Thiol-Ene “Click” Chemistry and its Applications in Polymer and Materials Chemistry ................................................................................... 19 1.1.1. “Click” Chemistry ............................................................................................. 19 1.1.2. Thiol-Ene “Click” Chemistry ....................................................................... 21 1.1.3. Applications of Thiol-Ene “Click” Chemistry ........................................ 26 1.1.3.1. Polymer and Macromer Synthesis ..................................................................... 26 1.1.3.2. Polymeric Materials ................................................................................................. 32 1.2. Porous Polymers ......................................................................................... 37 1.2.1. Synthesis of Emulsion Templated Porous Polymers ......................... 38 1.2.1.1 High Internal Phase Emulsions ............................................................................ 39 1.2.1.2 High Internal Phase Emulsion Templated Porous Polymers ................... 40 1.2.2. Functional Porous Polymer by High Internal Phase Emulsion Templating ......................................................................................................... 45 1.2.2.1. Emulsion Templating of Hydrophilic Monomers ......................................... 48 1.2.2.2. Photopolymerization ............................................................................................... 50 1.2.3. Applications of Emulsion Templated Porous Polymers ......................... 53 1.2.3.1. Enzyme Immobilization ......................................................................................... 53 1.2.3.2. Hydrogen Storage ..................................................................................................... 54 1.2.3.3. Tissue Engineering and 3D Cell Culture .......................................................... 57 1.3. Aims and Objectives ....................................................................................... 60 2. Experimental .................................................................................................... 62 2.1. PolyHIPE Synthesis ..................................................................................... 62 3 | P a g e 2.1.1. Materials ............................................................................................................. 62 2.1.2. PolyHIPE Preparation .................................................................................... 62 2.1.3. PFPA-PolyHIPE Preparation ........................................................................ 63 2.1.4. UV Curing ............................................................................................................ 63 2.2. PolyHIPE Functionalization – Residual Thiol .................................... 63 2.2.1. Materials ............................................................................................................. 63 2.2.2. UV Initiated Post-Polymerization Functionalization of PolyHIPEs by Clicking to Residual Thiols ..................................................................... 63 2.2.3. Thermally Initiated Post-Polymerization Functionalization of PolyHIPEs by Clicking to Residual Thiols ............................................... 64 2.2.4. Post-Polymerization Functionalization of PolyHIPEs by Amine Catalysed Michael Addition .......................................................................................... 64 2.2.5. Post-Polymerization Formation of Disulphide Bonds by Disulphide Exchange ............................................................................................................. 65 2.2.6. Post-Polymerization Formation of Disulphide Bonds via a Sulfenylthiosulphate Intermediate ........................................................... 65 2.3. PolyHIPE Functionalization – PFPA ...................................................... 66 2.3.1. Materials ............................................................................................................. 66 2.3.2. PFPA Synthesis ................................................................................................. 66 2.3.3. Post-Polymerization Functionalization of PFPA-PolyHIPEs – Tris(2-Aminoethyl) Amine ........................................................................... 66 2.3.4. Post-Polymerization Functionalization of PFPA-PolyHIPEs – L- Alanine ................................................................................................................ 66 2.3.5. Post-Polymerization Functionalization of PFPA-PolyHIPEs – RGD .... ................................................................................................................................ 67 2.4. Peptide Synthesis ........................................................................................ 68 2.4.1. Materials ............................................................................................................. 68 2.4.2. Peptide (GGRGD) Synthesis ......................................................................... 68 2.5. PolyHIPE Characterization ...................................................................... 69 2.5.1. Raman .................................................................................................................. 69 2.5.2. Solid State NMR Spectroscopy .................................................................... 69 2.5.3. XPS ........................................................................................................................ 70 2.5.4. FT-IR ..................................................................................................................... 70 2.5.5. Elemental Analysis .........................................................................................
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