Syntheses and ROMP of norbornene-functionalised polyesters and polyurethanes and evaluation of their products

• Main Author: Atter, Kieran Timothy
• Published: Durham University 2018
• Subjects: 540
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.743209

The aim of this project is to develop a polymer system which: 1) incorporates one or more norbornene rings in the pre-polymer; 2) can be polymerised using ROMP to yield linear or cross-linked polymers; 3) utilises little, or no, styrene; 4) produces products with comparable properties to current unsaturated polyester resins; 5) can polymerise in solvent, or in the presence of a reactive diluent; 6) is as environmentally friendly as possible; and 7) is as cost-effective as possible. Chapter 1 contains a history of olefin metathesis, ROMP, and ROMP catalysts. Using ROMP to polymerise norbornene-containing monomers is also included, as well as the synthesis of random and block-copolymers using ROMP. In Chapter 2, norbornene-containing polyesters – synthesised at Scott Bader – are characterised using 1H and 13C NMR spectroscopy, and SEC. The syntheses of hexamethylene-1,6-bis(5-norbornene-2-methoxy tetraethylene glycol carbamate) (DFM1); 2-hydroxyethyl-5-norbornene-2-carboxylate (HE-NBE-CO2); hexamethylene-1,6-bis(5-norbornene-2-carboxylate-2-ethoxy carbamate) (DFM2); and 2-hydroxyethyl-5-norbornene-2-carboxylate butyl carbamate (MFM) are all reported, and confirmed by characterisation using 1H and 13C NMR spectroscopy and ASAP mass spectrometry. Chapter 3 details the polymerisation of N-2-ethylhexyl norbornene dicarboximide (EHNBEDC) using Grubbs 1st generation (G1); 2nd generation (G2); and modified 2nd generation (MG2) catalysts; and analyses thereof. As well as this, Polyesters 1 and 2 are shown to undergo ROMP with all three catalysts and cross-link to form a gelled polymer. The gel contents and gel time of which was measured. Finally, Polyesters 1 and 2 are copolymerised with EHNEBDC using the three catalysts and shown to increase the gel contents with increasing concentration of the polyester. In Chapter 4, styrene is added to the reaction mixture for the ROMP of Polyesters 1 and 2. Increasing the level of styrene up to 2 equivalents with respect to the initiator is shown to have no effect on the gel contents with any of G1, G2 or MG2. However, the gel time can be increased by increasing the styrene up to 5 equivalents with respect to G1 or G2; though there is no increase in gel time observed when using styrene with MG2. Chapter 5 shows that MFM, DFM1 and DFM2 can be polymerised using ROMP with G1, G2 and MG2. The ROMP of MFM produces a linear polymer which can be characterised using 1H and 13C NMR spectroscopy, as well as SEC. DFM1 and DFM2 produce cross-linked polymers when they undergo ROMP. MFM can produce a block copolymer with EHNBEDC when using G1 as the initiator. Random and block copolymers of HE-NBE-CO2 and MFM are also formed using varying levels of each monomer. Some of the copolymer systems are tested using Dynamic Mechanical and Thermal Analysis (DMTA): measuring their Tg’s and storage moduli. In-mould bulk copolymers, using MG2 as the initiator, are achievable in several copolymer systems. Any trends in the Tg, or storage modulus, are investigated for each system. Finally, Chapter 6 offers conclusions to the work undertaken and some possible future work to further understand the polyesters and polyurethanes and their ROMP products, as well as the possibility of increasing the library of polyesters and polyurethanes using differing starting materials.