Available at: https://digitalcommons.calpoly.edu/theses/556
Date of Award
MS in Polymers and Coatings
Chemistry & Biochemistry
The use of nonionic associative thickeners was proposed for personal care applications. Various limitations of current rheology modifiers used in personal care were discussed. Nonionic associative polymers were examined as both thickeners and emulsifiers. The structure/property relationship for nonionic polymers and their ability to thicken and emulsify were fully examined. Results showed an increase in thickening efficiency for nonionic associative polymers with higher log(P) (partition coefficient) values. This was due to the formation of smaller aggregates and increased bridging between aggregates. The connection between oil polarity, log(P) of the associative polymer, and emulsion stability showed no relationship however; as the log(P) value of the polymer decreased, emulsion stability increased. The effects of nonionic associative polymer molecular weight and thickening efficiency proved to be positive; as molecular weight increased, thickening efficiency increased. Specific interactions between nonionic associative thickeners and common ingredients in personal care products were also explored. The interaction between nonionic associative thickeners and surfactants proved to be dependent on surfactant type as well as hydrophobe shape and size on the associative thickener. There appeared to a clear effect of salt on the thickening and emulsifying capabilities of the nonionic associative polymers but the exact interaction was not yet determined.
Superoxide dismutation (SOD) chemistry pertaining to manganese enzymes was explored. A series of manganese SOD mimetic enzymes were synthesized and their SOD activity was examined. The McCord-Fridovich Assay showed mimetic enzymes containing secondary amine bonds and electron difficiency around bonding sites had higher SOD activity. Click chemistry was used for the synthesis of a 1,4-triazole containing tridentate ligand. The ideal reaction conditions chosen for the click reaction was a solvent blend of 1:1 dichloromethane and water with copper sulfate and sodium ascorbate as a catalyst. The tridentate ligand was grafted onto azido-functionalized polystyrene. Infrared spectroscopy was used to confirm the completion of the click reaction. The azide peak at 2100 cm-1 was removed after the click reaction was performed on the azido-functionalized polystyrene.