<p> In part I of this dissertation, several cationic polyacrylamides were tested under different conditions for their ability to improve the retention of fines in papermaking. A dynamic drainage jar was used to simulate the turbulence encountered in the papermaking process. Several factors, including temperature, the amount and intensity of turbulence, the additive concentration and the presence of impurities were found to affect fines retention with polymers present. A polymer made by Nalco Chemicals proved to be superior to a commonly used polymer, Percol 292 for a standard fine paper pulp. It was thought that further retention improvements might be possible by tailoring the charge density and molecular weight of polyacylamide retention aides for the specific papermaking system they are intended for. Novel approaches to retention such as those employing combinations of an anionic polymer, a cationic polymer and zirconium oxychloride were thought to show promise as well.</p> <p> In part II of this dissertation several broad polyacrylamide molecular weight standards were prepared by inverse suspension and solution processes on pilot plant equipment at the McMaster Institute for Polymer Production Technology. They were characterized by laser light scattering and viscometry at McMaster, and externally by other methods. Although the polyacrylamides prepared compare favourably to currently available commercial standards when both are analysed by SEC, further analysis must be done to be certain of the molecular weight averages.</p> <p> A relationship is presented to provide for simpler and more accurate light scattering analysis in the future. This relationship relating Mw to the second Virial coefficient may be used to eliminate some uncertainty in the often scattered plots encountered when calculating molecular weights for polyacrylamides analysed by light scattering.</p> / Thesis / Master of Engineering (MEngr)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/19420 |
| Date | 05 1900 |
| Creators | Stanislawczyk, Vic |
| Contributors | Hamielec, A. E., Chemical Engineering |
| Source Sets | McMaster University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
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