Non-polar phase selective solubility of modified poly(4-n-alkylstyrene) supports can be measured using fluorescent dyes as catalyst surrogates with thermomorphic and latent biphasic systems. By modifying the solvent compositions in heptane/ethanol and heptane/N, N-dimethylacetamide, increased non-polar phase selective solubility of modified polystyrene supports can be attained. Likewise, by varying the structure and length of the pendant alkyl chain, an increase in non-polar phase selective solubility is measured. These heptane soluble polymer supports can be useful for applications involving heptane soluble polymer-bound reagents and catalysts. Various polar and non-polar polymer supports were synthesized with an attached solvatochromic catalyst surrogates to determine the solvent accessibility of the supported species in pure and mixed solvents. The results of these studies indicate that in pure solvents, the influence of both polar and non-polar polymer supports on the solvent microenvironment of these polymer-supported probes is minimal. In mixed solvent systems, a polymer-like solvent microenvironment is measured in solvent mixtures comprised of solvents the polymer has unfavorable interactions. Poly(4-n-alkylstyrene) and internally functionalized polyisobutylene supports are two such polymer supports that exhibit this behavior. For terminally functionalized polymers in mixed solvents, the solvatochromic behavior does not indicate a collapsed structure. In mixed solvents, there is minimal influence of the polymer support on the solvent microenvironment of these terminally functionalized polymers. The application of soluble polyisobutylene supported copper complexes in the ATRP polymerization of styrene was investigated. Using the difference in solubility of the product polystyrene and the polyisobutylene copper complex in heptane, a solid/liquid separation of the soluble copper complex from the solid product was achieved. The results of these polymerizations indicate that the polyisobutylene copper complex behaves exactly like a low molecular weight copper complex in terms of control over molecular weight and molecular weight distribution. After the polymerizations, the polyisobutylene complexes could be separated as a heptane solution and recycled in multiple polymerizations of styrene.

Thesis (Ph. D.)--Institute of Paper Chemistry, 1967. / Includes bibliographical references (p. 90-93).

No description available.

No description available.

This investigation is concerned with the assessment of the performance of a novel spinning disc reactor (SDR) for the polymerisation of chemically initiated freeradical polymerisation of styrene. The application of high acceleration fields such as those created on the surface of the grooved rotating disc to the polymerising system is aimed at intensifying the polymerisation rate and producing a better quality polymer product. As part of the experimental programme, four separate sets of experimental runs were conducted on a 360 mm diameter grooved rotating disc at a fixed temperature of 88-90°C to explore the effects of disc rotational speed and prepolymer feed conversion/viscosity on the extent of monomer conversion and molecular weight properties (M., MW and MWD) of the product from the SDR. The performance data of the SDR was compared with conventional batch polymerisation data. Both the disc rotational speed and prepolymer feed conversion/viscosity variables were found to have a profound influence on the performance of the SDR. A steady increase in conversion, rate of polymerisation and hence time saving in one pass in the SDR were observed with a rise in the prepolymer feed conversion and rotational speed until, for the latter, an optimal speed of rotation which gave the highest rate of polymerisation was reached. The results have been explained in relation to the effect of disc speed and prepolymer feed viscosity on mean film thickness, mean residence time and film surface instabilities. Furthermore, the SDR product is seen to have generally improved characteristics in terms of narrower molecular weight distribution when compared to polymer prepared in the batch at the same conversion. The large enhancement of the rate of styrene polymerisation in the SDR was discussed in terms of a possible improvement in the BPO initiator efficiency f and non-stationary state polymerisation conditions likely to be prevalent on the rotating disc. The general improvement in SDR product quality was ascribed to the combined effects of a reduced diffusion path length and an intense mixing mechanism within the thin film. A separate experimental study exploring the effects of micromixing efficiency on the conversion and molecular weight properties of styrene polymerisation in the batch was also undertaken. The opposing effects of enhanced micromixing in batch and continuous polymerisation systems were contrasted in a theoretical manner. A theoretical case study highlighting the energy efficiency of the SDR was also carried out. Savings in energy of more than 70% was calculated for a semi-batch process using an industrially adapted spinning disc reactor in comparison to a purely batch process. Finally, a two-stage continuous industrial process for free-radical polymerisation has been proposed consisting of an enhanced tubular reactor in the first stage followed by a parallel arrangement of several rotating disc surfaces. Improvements in intrinsic safety and minimised risks of polymer degradation and thermal runaways are the expected potential benefits. Keywords: Process Intensification, Thin Film, Spinning Disc Reactor, Free Radical Polymerisation, Polystyrene

Thesis (Ph.D.)--University of Wollongong, 2004. / Typescript. Includes bibliographical references: p. 172-180.

Thesis (M.S.)--Rochester Institute of Technology, 2004. / Typescript. Includes bibliographical references (leaves 46-48).

Thesis (M.Sc.). / Written for the Dept. of Chemistry. Title from title page of PDF (viewed 2009/06/29). Includes bibliographical references.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: Polymer; polystyrene; electrospinning; rheology. Includes bibliographical references (leaves: 67 - 68 ).

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references (leaves 71-72). Also available in electronic version.