Absolut “copper catalyzation perfected”; robust living polymerization of NIPAM : Guinness is good for SET-LRP

The controlled polymerization of N-isopropyl acrylamide (NIPAM) is reported in a range of international beers, wine, ciders and spirits utilizing Cu(0)-mediated living radical polymerization (SET-LRP). Highly active Cu(0) is first formed in situ by the rapid disproportionation of [Cu(I)(Me6-Tren)Br] in the commercial water–alcohol mixtures. Rapid, yet highly controlled, radical polymerization follows (Đ values as low as 1.05) despite the numerous chemicals of diverse functionality present in these solvents e.g. alpha acids, sugars, phenols, terpenoids, flavonoids, tannins, metallo-complexes, anethole etc. The results herein demonstrate the robust nature of the aqueous SET-LRP protocol, underlining its ability to operate efficiently in a wide range of complex chemical environments

A ‘greener’ one-pot synthesis of monoterpene-functionalised lactide oligomers

© 2020 Elsevier Ltd In this work we aimed to achieve a totally sustainable Ring Opening Polymerisation (ROP) process, by harmonising the use of naturally occurring or derivable initiators and the green solvent 2-Methyltetrahydrofuran (2-MeTHF). First, a library of novel monoterpene-alcohols and existing terpenoids was used to provide renewably sourced initiators for a metal-free ROP synthetic step. A number of these initiators are derived from waste materials, further improving their sustainability. Secondly, we selected lactide (LA) as a monomer, because not only is it derived from biomass, but its resultant polymers are biocompatible and biodegradable. Interestingly, these new polymers self-assembled in water producing well defined, biocompatible nanoparticles (NPs) via direct nanoprecipitation without the use of additional stabilisers. We have highlighted a novel and promising (ROP) approach to produce biodegradable, amphiphilic ester-based macromolecules, based on lactide and terpenes (as initiators) in a green solvent, 2-MeTHF thus reducing solvent toxicity in an efficient, simple and sustainable new synthesis. The monoterpenes may provide a highly functionalisable and bio-renewable toolbox for a new generation of ROP initiators

Industrial exploitation of supercritical carbon dioxide as a solvent

The work described in this thesis can be divided into two main topic areas; the synthesis of polymer particles via dispersion polymerisation using supercritical carbon dioxide (scCO2) as the reaction medium and the scale-up of these reactions. The fundamental concepts used to achieve these aims are detailed in Chapter 1. As high pressures and temperatures are involved, utilising scCO2 as a reaction medium requires specialised equipment. The high-pressure equipment used throughout this thesis is summarised in Chapter 2. This includes the details of a 1 L high-pressure autoclave, previously only used for extraction, which has been used for the scale-up of polymer synthesis. The techniques used to analyse the polymers produced are also outlined. The first main topic area of this thesis is the synthesis of polymer particles via dispersion polymerisation, which is discussed in Chapter 3. The first structure investigated is a poly(methyl methacrylate) (PMMA) particle incorporating a crosslinking component. The loading of the crosslinking component was varied to establish the effect this had on the particle structure, as well as the glass transition temperature (Tg). These parameters were probed using scanning electron microscopy (SEM) and dynamic mechanical analysis (DMA) respectively. A second particle of interest contained a core-shell internal morphology. Two monomer composition were investigated, both containing a PMMA shell encasing either a poly(butyl acrylate) (PBA) or poly(benzyl acrylate) (PBzA) core. The loading of the core material (BA or BzA) was gradually increased and once again the changes in the particle morphology and Tg were probed. The ability to preferentially stain the PBzA allowed for probing of the internal morphology of the PBzA containing particles using transmission electron microscopy (TEM). Utilising scCO2 as the reaction medium removes the need for high-energy post polymerisation drying steps usually associated with dispersion polymerisations carried out in traditional solvents. However, despite numerous advantages, scale remains a hurdle which has thus far limited the applicability of scCO2 for the commercial production of polymer particles. As this thesis was industrially funded, the second topic area of investigation was the feasibility of increasing the scale of the high-pressure reactions, which is discussed in Chapter 4. The dispersion polymerisation of methyl methacrylate (MMA) was chosen as a model system as it has been well-studied in the literature. In this Chapter, comparisons are made between the particles produced on a small (60 mL) scale and those produced on a larger (1 L) scale using analogous reaction conditions. SEM was used to analyse the morphology of the particles produced. Control of the particle size, by variation of the concentration of the poly(dimethyl siloxane) stabiliser (PDMS) is demonstrated, with similar size particles being produced on both scales. The desired application for these particles is as impact modifiers. With this in mind, the synthesised particles were combined with various PVC formulations and tested at Kaneka Belgium. Several industrially standard tests were performed, including Brabender torque rheometry, transparency and Izod impact tests. The results of these tests are summarised in Chapter 5. Comparisons are made between the particles synthesised in Nottingham and those produced commercially by Kaneka, intended for the same application. These tests allowed for conclusions to be drawn about the composition of the particles as well as the internal morphology present. The data collected complimented the analysis carried out in Nottingham. It also provided an opportunity to assess areas that could be improved upon in the future production of particles

Industrial exploitation of supercritical carbon dioxide as a solvent

The work described in this thesis can be divided into two main topic areas; the synthesis of polymer particles via dispersion polymerisation using supercritical carbon dioxide (scCO2) as the reaction medium and the scale-up of these reactions. The fundamental concepts used to achieve these aims are detailed in Chapter 1. As high pressures and temperatures are involved, utilising scCO2 as a reaction medium requires specialised equipment. The high-pressure equipment used throughout this thesis is summarised in Chapter 2. This includes the details of a 1 L high-pressure autoclave, previously only used for extraction, which has been used for the scale-up of polymer synthesis. The techniques used to analyse the polymers produced are also outlined. The first main topic area of this thesis is the synthesis of polymer particles via dispersion polymerisation, which is discussed in Chapter 3. The first structure investigated is a poly(methyl methacrylate) (PMMA) particle incorporating a crosslinking component. The loading of the crosslinking component was varied to establish the effect this had on the particle structure, as well as the glass transition temperature (Tg). These parameters were probed using scanning electron microscopy (SEM) and dynamic mechanical analysis (DMA) respectively. A second particle of interest contained a core-shell internal morphology. Two monomer composition were investigated, both containing a PMMA shell encasing either a poly(butyl acrylate) (PBA) or poly(benzyl acrylate) (PBzA) core. The loading of the core material (BA or BzA) was gradually increased and once again the changes in the particle morphology and Tg were probed. The ability to preferentially stain the PBzA allowed for probing of the internal morphology of the PBzA containing particles using transmission electron microscopy (TEM). Utilising scCO2 as the reaction medium removes the need for high-energy post polymerisation drying steps usually associated with dispersion polymerisations carried out in traditional solvents. However, despite numerous advantages, scale remains a hurdle which has thus far limited the applicability of scCO2 for the commercial production of polymer particles. As this thesis was industrially funded, the second topic area of investigation was the feasibility of increasing the scale of the high-pressure reactions, which is discussed in Chapter 4. The dispersion polymerisation of methyl methacrylate (MMA) was chosen as a model system as it has been well-studied in the literature. In this Chapter, comparisons are made between the particles produced on a small (60 mL) scale and those produced on a larger (1 L) scale using analogous reaction conditions. SEM was used to analyse the morphology of the particles produced. Control of the particle size, by variation of the concentration of the poly(dimethyl siloxane) stabiliser (PDMS) is demonstrated, with similar size particles being produced on both scales. The desired application for these particles is as impact modifiers. With this in mind, the synthesised particles were combined with various PVC formulations and tested at Kaneka Belgium. Several industrially standard tests were performed, including Brabender torque rheometry, transparency and Izod impact tests. The results of these tests are summarised in Chapter 5. Comparisons are made between the particles synthesised in Nottingham and those produced commercially by Kaneka, intended for the same application. These tests allowed for conclusions to be drawn about the composition of the particles as well as the internal morphology present. The data collected complimented the analysis carried out in Nottingham. It also provided an opportunity to assess areas that could be improved upon in the future production of particles

Terminal functional glycopolymers via a combination of catalytic chain transfer polymerisation (CCTP) followed by three consecutive click reactions

The combination of catalytic chain transfer polymerisation (CCTP) with both thiol-ene and copper catalysed alkyne azide coupling (CuAAC) click chemistry has been employed to give a new route to functional glycopolymers for applications in bioconjugation and biological targeting. Ring opening of poly(glycidyl methacrylate) with sodium azide and subsequent reaction with alkyne functional carbohydrates, as prepared by Fischer glycosylation, has been exploited. This combination of a range of efficient chemistry gives a route to multi gram quantities of glycopolymers avoiding the need for living radical polymerisation chemistry. © 2012 The Royal Society of Chemistry

Multiblock sequence-controlled glycopolymers via Cu(0)-LRP following efficient thiol–halogen, thiol–epoxy and CuAAC reactions

The combination of copper(0) mediated living radical polymerization (Cu(0)-LRP) with thiol–halogen, thiol–epoxy and copper catalysed alkyne azide coupling (CuAAC) click chemistry has been employed to give a new route to multiblock sequence-controlled glycopolymers. Multiblock poly(glycidyl acrylate)-co-(acrylic acid 3-trimethylsilanyl-prop-2-ynyl ester) (poly(GA)-co-(TMSPA)) were obtained by Cu(0)-LRP in DMSO at ambient temperature via iterative monomer addition whereby the sequence of the multi blocks is attained in a designed way. Thiol–halogen and thiol–epoxy reaction of poly(GA) have been exploited, which suggested a preference for the reaction of the halogen rather than the epoxide for the thiol with triethyl amine as catalyst. The obtained multiblock poly(GA)-co-(TMSPA) were then used for sequential thiol–halogen, thiol–epoxy and CuAAC reactions to build functional glycopolymers in defined sequence

Aqueous copper-mediated living radical polymerisation ofN-acryloylmorpholine, SET-LRP in water

The polymerisation of N-acryloylmorpholine in water is reported utilising Cu(0)-mediated living radical polymerisation (SET-LRP). The inherent instability of [CuI(Me6-Tren)Br] in aqueous solution is exploited via rapid disproportionation to prepare Cu(0) particles and [CuII(Me6-Tren)Br2] in situ prior to addition of monomer and initiator. Quantitative conversion is attained within 30 min for various degrees of polymerisation (DPn = 20–640) with SEC showing symmetrical narrow molecular weight distributions (Đ < 1.18) in all cases. Optimised conditions are subsequently applied for the preparation of a diblock copolymer poly(NIPAm)-b-(N-acryloylmorpholine), illustrating the versatility of this approach

Organocatalytic synthesis of vinylene carbonates

The organocatalytic synthesis of vinylene carbonates from benzoins and acyloins was studied using diphenyl carbonate as a carbonyl source. A range of N-Heterocyclic Carbene (NHC) precursors were screened and it was found that imidazolium salts were the most active for this transformation. The reaction occurs at 90°C under solvent-free conditions. A wide range of vinylene carbonates (symmetrical and unsymmetrical, aromatic or aliphatic), including some derived from natural products, were prepared with 20-99% isolated yields (24 examples). The reaction was also developed using thermomorphic polyethylene-supported organocatalysts as recoverable and recyclable species. The use of such species facilitates the workup and allows the synthesis of vinylene carbonates on the preparative scale (> 30 g after 5 runs)

A medieval farming glossary of Latin and English words Taken mainly from Essex records

SIGLEAvailable from British Library Document Supply Centre-DSC:3812.050(138) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Absolut “copper catalyzation perfected”; robust living polymerization of NIPAM: Guinness is good for SET-LRP

The controlled polymerization of N-isopropyl acrylamide (NIPAM) is reported in a range of international beers, wine, ciders and spirits utilizing Cu(0)-mediated living radical polymerization (SET-LRP). Highly active Cu(0) is first formed in situ by the rapid disproportionation of [Cu(I)(Me6-Tren)Br] in the commercial water–alcohol mixtures. Rapid, yet highly controlled, radical polymerization follows (Đ values as low as 1.05) despite the numerous chemicals of diverse functionality present in these solvents e.g. alpha acids, sugars, phenols, terpenoids, flavonoids, tannins, metallo-complexes, anethole etc. The results herein demonstrate the robust nature of the aqueous SET-LRP protocol, underlining its ability to operate efficiently in a wide range of complex chemical environments.ISSN:1759-9962ISSN:1759-995