SYNTHESIS OF SURFACE-ACTIVE POLYMERIZABLE MONOMER AND CHEMICALLY FUNCTIONAL POLYMER COLLOIDS DERIVED THEREFROM

Date of Completion

January 1983

Keywords

Chemistry, Polymer

Degree

Ph.D.

Abstract

Model colloids having known particle size and surface chemistry are highly desirable for use in a variety of studies, such as colloid stability, interactions between particles and walls, and measurement of diffusion coefficients. Independent control of particle size and surface functional group density cannot, however, be achieved by conventional emulsion polymerization methods. This dissertation is concerned with a method by which these goals can be accomplished by means of the surface-active comonomers, sodium sulfodecylstyrylether (SSDSE) and styryloxyldecyltrimethylammonium bromide (SODTAB). These comonomers were synthesized through four-step sequences of reactions starting from coumarin.^ A series of monodisperse polystyrene latexes of the same size has been prepared covering a range of surface charge densities from ca. 1.0 to 10.0 (mu)C/cm('2). These latexes were synthesized by a two-step process. First, a monodisperse latex with low surface charge density was formed by means of conventional emulsion polymerization. Then, a seed copolymerization with the surface-active comonomer was used to control the surface charge density of the latex. These series of latexes were highly purified and used as model colloids to investigate the influence of the surface charge density on the colloid stability.^ The coagulation kinetics of the latex in different electrolyte solutions were determined by light scattering photometry. The effect of the surface charge density on a calculated value for the Hamaker constant and the Stern potential were obtained. It was found that interactions other than van der Waals attractive forces and double layer electrostatic repulsive forces are probably involved in a colloidal system, especially for high surface charge density latexes. ^

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