Among the water-soluble polymers in which interest has been increasing recently, quaternary ammonium polymer is considered to be most extensively used, but very few kinetic studies have been conducted in the preparation of those polyelectrolytes. In the present work authors made an effort to elucidate the kinetic aspects of quaternization reaction of high polymer.
Polystyrene was chloromethylated with chloromethyl ether and quaternization reaction was carried out with tertiary amines including triethylamine, diethyl ethanolamine and pyridine in the media of dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP), dioxane and tetrahydrofuran (THF).
The results of experiments showed that the rate of quaternization had been affected greatly by the basicity of amines and polarity of solvents. Rate constants changed in the order of dielectric constant values of solvents except dioxane as follows : (Values in parenthesis indicate dielectric constants.)
DMF (36.7) >NMP (33.0) >Dioxane (2.2) >THF (7.4)
This peculiar behavior of dioxane was considered to be attributed to an increase in the micro-dielectric constant value over the bluk value in virtue of the specific solvation of dioxane to the quaternary ammonium salt. Solubility parameter has been found to be used with better correlation to rate constant than dielectric constant. Isokinetic relationship has also been observed between activation energy and entropy in all solvents except dioxane.
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