Yes / It has been shown that seeded granules of calcium carbonate can be produced in commercial batch high shear granulators such as the Cyclomix high-shear impact mixer. Seeded granules are attractive to the pharmaceutical industry due to their high uniformity and good mechanical properties which can assist efficient tablet manufacture. In the current study, attempts to produce seeded granules of Durcal 65 and PEG 4000 binder using hot melt granulation are reported, in response to the recent shift towards continuous pharmaceutical manufacturing. Various screw configurations and rotation speeds were investigated in a series of experiments to determine the relationship between process conditions and granule properties. Particle size analysis, strength measurement and structural characterisation were used to quantify granule properties. It was found that using a series of kneading elements arranged at a 60° staggering angle located near to the feed section of the extruder screw generated strong, spherical granules. From structural characterisation approximately 5–15% of extruded granules were found to be seeded. Twin screw melt granulation is therefore considered to be a promising technique for continuous production of seeded granules, although a more detailed investigation is required to optimise yield and quality.

The main theme of this research is to understand the structure-property evolution during crystallization of a semicrystalline thermoplastic polymer. A combination of techniques including rheology, small angle light scattering, differential scanning calorimetry and optical microscopy are applied to follow the mechanical and optical properties along with crystallinity and the morphology. Isothermal crystallization experiments on isotactic poly-1-butene at early stages of spherulite growth provide quantitative information about nucleation density, volume fraction of spherulites and their crystallinity, and the mechanism of connecting into a sample spanning structure. Optical microscopy near the fluid-to-solid transition suggests that the transition, as determined by time-resolved mechanical spectroscopy, is not caused by packing/jamming of spherulites but by the formation of a percolating network structure. The effect of strain, Weissenberg number (We) and specific mechanical work (w) on rate of crystallization (nucleation followed by growth) and on growth of anisotropy was studied for shear-induced crystallization of isotactic poly-1-butene. The samples were sheared for a finite strain at the beginning of the experiment and then crystallized without further flow (Janeschitz-Kriegl protocol). Strain requirements to attain steady state/ leveling off of the rate of crystallization were found to be much larger than the strain needed to achieve steady state of flow. The large strain and We >1 criteria were also observed for morphological transition from spherulitic growth to oriented growth. An apparatus for small angle light scattering (SALS) and light transmission measurements under shear was built and tested at the University of Massachusetts Amherst. As a new development, the polarization direction can be rotated by a liquid crystal polarization rotator (LCPR) with a short response time of 20 ms. The experiments were controlled and analyzed with a LabVIEWTM based code (LabVIEWTM 7.1) in real time. The SALS apparatus was custom built for ExxonMobil Research in Clinton NJ.

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In an effort to synthesize macromolecules comprising both covalent and non-covalent bonding to tune ultimate physical properties, a variety of methodologies and functionalization strategies were employed. First, protected functional initiation, namely 3-[(N-benzyl-N-methyl)amino]-1-propyllithium and 3-(t-butyldimethylsilyloxy)-1-propyllithium, in living anionic polymerization of isoprene was used to yield well-defined chain end functional macromolecules. Using both initiating systems, polymers with good molar mass control and narrow molar mass distributions were obtained and well-defined chain end functionality was observed. There was no observed effect on the polymer microstructure from the polar functionality in the initiator, with ~92% 1,4- and 8% 3,4-enchainment observed in each case. Further investigation of the 3-[(N-benzyl-N-methyl)amino]-1-propyllithium initiated polyisoprenes proved that facile deprotection was not possible and residual catalyst was not removable from the polymer. However, polymers initiated with 3-(t-butyldimethylsilyloxy)-1-propyllithium were quantitatively hydrogenated and deprotected under relatively mild conditions to yield hydroxyl functional macromolecules in several architectures, including linear and star-shaped. Excellent conversion from arm polymer to star polymer was observed and well-defined macromolecules were obtained. Subsequently, a series of non-functional, hydroxyl functional, and 2-ureido-4[1H]-pyrimidone (UPy) chain end functional linear and star-shaped poly(ethylene-co-propylene)s were synthesized and characterized. The melt phase properties were investigated using melt rheology and the effect of macromolecular topology and multiple hydrogen bond functionality was investigated. Linear UPy functional poly(ethylene-co-propylene)s exhibited increased viscosity and shear thinning onset at lower frequencies than non-functional polymers of similar molar mass due to interaction of the multiple hydrogen bonding groups. Star-shaped UPy functional poly(ethylene-co-propylene)s showed inhibition to terminal flow and the absence of a zero shear viscosity in melt rheological characterization, indicative of a network like structure imparted from the multiple hydrogen bonding interactions. In addition, the living anionic polymerization of D3 was controlled using the functionalized initiators3-[(N-benzyl-N-methyl)amino]-1-propyllithium and 3-(t-butyldimethylsilyloxy)-1-propyllithium. Good molar mass control and narrow molar mass distributions were observed. In contrast to the polyisoprene homopolymers, facile deprotection of the 3-(t-butyldimethylsilyloxy)-1-propyllithium was not possible due to the acid sensitivity of the poly(dimethylsiloxane) backbone. However, facile deprotection of the protected secondary amine was achieved through hydrogenolysis and well-defined terminal amine functionalized poly(dimethylsiloxane) was synthesized, which are then amenable to further functionalization reactions. In contrast to the well-defined polymers synthesized using living anionic polymerization, free radical polymerizations was used to synthesize free radical copolymers with broader polydispersities and pendant UPy groups. These copolymers were compared with a simple dimeric hydrogen bonding carboxylic acid containing copolymer. Melt rheological characterization revealed that, at similar concentrations, the effect of the UPy group was much greater than the carboxylic acid, and broadened plateau moduli and increased viscosity for the UPy containing polymers were observed, while the acid containing polymer exhibited similar results to a non-functional control. The dynamic viscosity was observed to increase systematically with increasing UPyMA incorporation and the quadruple hydrogen bonding interactions were observed to dissociate between ~80-150 °C. / Ph. D.