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Ion containing copolymers via the emulsion copolymerization of polar and ionic vinyl monomersPackard, Kevan A. January 1983 (has links)
The synthesis of ion containing copolymers by emulsion copolymerization of polar vinyl monomers with ionic vinyl monomers has been studied. The copolymerization of n-butyl acrylate with sodium-pstyrene sulfonate proved to be particularly rapid. With the proper choice of chain transfer agent soluble polymers with enhanced rubbery plateaus have been synthesized. The best conditions for the polymerizations were a reaction temperature of 70°C and reaction times up to 8 hours with TWEEN 20 used as the emulsifier.
Analysis of the copolymer composition by UV spectroscopy, and potentionmetric titration was not possible due to the vastly different solubility characteristics of the components of this system. This prevented the use of homopolymer blends as standards for these techniques.
The study of the copolymerization kinetics of this system was very difficult due to the coagulation of the polymer latex. The rate of copolymerization was nevertheless shown to be very rapid.
The synthesis of the sulfonated styrene monomer by a literature procedure led to the formation of a covalent sulfonamide instead of the desired ionic sulfonate. This product was substantiated by l<sub>H</sub> and 13<sub>C</sub> NMR infrared, mass spectral, and melting point data.
Study of the physical properties of these polymers by differential scanning calorimetry and thermal mechanical analysis showed them to have only a low temperature acrylate glass transition with an enhanced rubbery plateau due to the ionic pseudo crosslinking. Stress-strain measurements showed that this pseudo crosslinking gives enhanced tensile properties (modulus, tensile strength) in the ion-containing polymers. / M.S.
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