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The main aim of this project was to investigate the possibility of manufacturing 3D parts of polyamide (nylon or PA) 6 by inkjetting its monomer caprolactam (CL). The principle of this process was similar to the other rapid prototype (RP) and rapid manufacturing (RM) processes in which a 3D part is manufactured by layer on layer deposition of material. PA6 was used as the thermoplastic polymer in this work because of its good properties and also because PA6 can be produced by heating its monomer (i.e. plus catalyst and activator) in a short time. Two polymerisation mixtures of CL-catalyst (mixture A) and CL-activator (mixture B) are intended to be jetted separately using conventional jetting heads and polymerise shortly after heating. Anionic polymerisation of CL (APCL) was investigated in the bulk and on a smaller scale. Sodium caprolactamate (CLNa and C10) and caprolactam magnesium bromide (CLMgBr) were used as catalysts and N-acetylcaprolactam (ACL) and a di-functional activator (C20) were used as activators. The influence of polymerisation conditions was investigated and optimised. These were catalyst-activator concentration, polymerisation temperature and the influence of the polymerisation atmosphere. The physical properties (monomer conversion, crystallinity, and viscosity average molecular weight) of PA6 samples produced using each catalyst-activator combinations were measured and compared. Small scale polymerisation was carried out using a hotplate, by hot stage microscopy and using differential scanning calorimetry (DSC). The influence of heating strategy on small scale polymerisation was studied using DSC. The polymerisation mixture compositions were characterised using rheometry, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and optical microscopy to investigate their suitability in jetting for using the available jetting heads. It was shown that the combination of CLMgBr-ACL resulted in fast polymerisation which was not sensitive to moisture. The C10-C20 combination resulted in fast polymerisation with the best properties in a protected environment (nitrogen); however, the polymerisation was affected by moisture in air and the properties of polymer produced and rate of polymerisation decreased in air. Polymers produced using CLNa-ACL had the poorest properties and polymerisation did not occur in air. Material characterisation showed that micro-crystals of CLMgBr existed in CLMgBr-CL mixture at the jetting temperature (80oC) which were too large to be jetted. However, the mixture of C10 in CL could be partially jetted. The activator mixtures had similar properties to CL and were easily jetted. Drop on drop polymerisation was carried out by dripping droplets of mixtures A and B (at 80oC) on top of each other on a hotplate at the polymerisation temperature. Small scale polymerisation in a DSC showed that the monomer conversion increased with increase in polymerisation temperature from 140oC to 180oC and decreased from 180oC to 200oC. The crystallinity of the polymer produced in the DSC decreased with increase in polymerisation temperature. Hot stage microscopy produced evidence for simultaneous polymerisation and crystallisation processes on heating. Small scale polymerisation in an oven and analysed by DSC showed that increasing catalystactivator concentration resulted in increasing monomer conversion and decrease in crystallinity. Monomer conversion also increased with increase in polymerisation temperature and polymerisation time. Comparison between small scale and bulk polymerisations shows a good agreement between the two polymerisation rates. This shows that the polymerisation mechanism did not change significantly when the quantity of materials was reduced to less than 20mg. Finally, the polymerisation was carried out in a DSC after jetting C10-CL and C20-CL mixtures into a DSC pan using a jetting system, which was made in another work.

Pulsed plasmas were investigated as a means of controlling the composition of the surfaces generated via plasma polymerisation. A variety of precursors were studied under a range of plasma conditions using both continuous wave and pulsed plasmas. Surface and bulk analytical techniques were used to characterise the deposited plasma polymers whilst deposition rate measurements aided in understanding the effects of altering the various plasma parameters. Continuous wave plasma polymerisation of saturated cyclic fluorocarbons yielded plasma polymers with high fluorine/carbon ratios. Plasma instability at low powers limits the extent to which continuous wave power can be used to achieve good selectivity in the polymerisation process. Pulsed plasma polymerisation of perfluoroallylbenzene was studied in detail to investigate the influence of pulsing parameters on the surface composition. Highly aromatic surfaces were obtained through retention of the perfluorophenyl group from the precursor. Deposition rate experiments confirmed polymerisation was taking place in the off-portion of the duty cycle for precursors with a functional group susceptible to radical initiated reactions. A cyclic siloxane precursor with vinyl substituents was used to generate surface consisting of siloxane rings in an organic matrix. The monomer structure was retained through the reaction of the vinyl groups in the off-portion of the duty cycle. For low duty cycle pulsed plasma polymers the Si:0 ratio of the plasma polymers was identical to that of the monomer, indicating successflil retention of monomer structure using pulsed plasmas. Preliminary investigations into the pulsed plasma polymerisation of styrene oxide yielded a range of polymer compositions with varying oxygen contents. The properties of the surfaces varied with oxygen content. The results indicate that pulsed plasmas can give significant enhancements over continuous wave plasmas in controlling surface composition and properties.

This thesis describes the synthesis of degradable materials based on functional aliphatic polycarbonates/polyesters synthesised via ring-opening copolymerisation (ROCOP) and post-polymerisation modifications. Chapter 3 details the synthesis of cationic poly(ester-b-carbonate-b-ester) via ringopening copolymerisation of CO₂ and vinyl-cyclohexene oxide (v-CHO), ringopening polymerisation (ROP) of rac-lactide, and subsequent post-polymerisation modifications of this material through a radical thiol-ene reaction and a quaternisation reaction. These cationic polymers show high surface zeta-potential (> 40 mV) and display effective antibacterial properties with killing efficiencies of > 99.9% against Gram-negative bacteria Escherichia coli. Chapter 4 describes the synthesis of amphiphilic block poly(phosphoester-b-carbonate-b-phosphoester)s using ROCOP of CO₂ and v-CHO and ROP of ethyl ethylene phosphate (EP). These amphiphilic block polymers self-assemble into either micelles or vesicles, depending on the hydrophobic/hydrophilic block ratio. The potential use of the vesicles in drug delivery is also described, and initial results detailing the enzymatic degradation of these vesicles are presented. In addition, the hydroboration-oxidation is investigated as a new post-polymerisation modification method to functionalise an alkene-containing polycarbonate, poly(vinylcyclohexene carbonate) (^VPC). The hydroxyl functionalised polycarbonate shows improved hydrophilicity and cell adhesion, compared to the unfunctionalised precursor. The side chain hydroxyl groups are then tested for making graft poly(carbonate-g-phosphoester). Chapter 5 further investigates the use of the hydroboration-oxidation reaction in functionalising poly(cyclohexadiene carbonate) (^CPC) and poly(vinylcyclohexenemaleate) (^V,MPE). A selective post-polymerisation modification is also demonstrated on a blend of ^CPC and ^VPC or ^V,MPE featuring both terminal and internal alkene groups using the hydroboration-oxidation method, where the terminal alkene groups are functionalised exclusively. Lastly, an orthogonal post-polymerisation approach is carried out on the unreacted internal alkene groups of hydroxyl-containing ^V,MPE via thiol-ene reactions to install other functional groups such as carboxyl, amine and methoxy-poly(ethylene glycol).

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This thesis describes the techniques of anionic polymerisation and characterisation used in the synthesis of poly(methyl methacrylate)/poly(ethylene oxide) diblock copolymers, the various surface techniques used to examine the interfacial properties of these copolymers spread on water, and the dynamics of these copolymers in solution. The surface techniques used were surface pressure-concentration isotherm studies, neutron reflectivity, surface quasi-elastic light scattering, and ellipsometry. The thermodynamics of micellization and dynamic properties of the copolymer solutions were investigated using light scattering. The diblock copolymers had a target composition of 50:50 mole ratio and M(_W) = 50000. In addition, several copolymers had one or both blocks holly deuterated which was necessary for the neutron reflectivity studies where contrast variation was required to apply the kinematic approximation. Surface pressure isotherms give thermodynamic information about the behaviour of polymer segments at the interface. It has been possible to interpret this behaviour by using neutron reflectivity to obtain information concerning die thickness and distribution of the PMMA and PEO blocks, and water at the interface. The trends in layer thickness have been supported by the ellipsometric measurements and interpretation of the viscoelastic SQELS data has allowed conclusions about the hydrodynamics of the polymer chains at various surface concentrations.

Research into the synthesis of sequential, poly(n-butyl acrylate), PnBA/polystyrene, PS, IPN microgel (μ-gel) dispersions in organic media was performed. Poly(styreneco- divinylbenzene), PSIDVB (0, 1, 5 & 10 weight % DVB), particles were synthesised by emulsion copolymerisation and these microgels were characterised by dynamic mechanical thermal analysis (DMT A), gel permeation chromatography and diffuse reflectance Fourier transform infrared (DRIFT) spectroscopy.