Effect of polymer as cosolvent on chemical reactions in solution—I. Effects of polystyrene and polyoxyethylene on the reaction of dansyl chloride with butylamine in organic solvents

The rates of reactions of 5-dimethylamino-1-naphthalenesulphonyl chloride (dansyl chloride) with butylamine in organic solvents have been measured in the presence of polymer such as polyoxyethylene (POE) or polystyrene (PS) as cosolvent and compared with those in the presence of cosolvents of low molecular weight analogues, viz. diethyloxyethane (DEE) and toluene (Tol.). Acceleration by cosolvent POE, compared with DEE, increases with increasing volume fraction of cosolvent and the effect depends on the degree of polymerization of the polymer cosolvent. Similarly, addition of cosolvent PS to ethyl acetate or chloroform results in increase in the reaction rate as compared with cosolvent Tol. The effect by PS also showed dependence on the degree of polymerization. The effect of polymer cosolvent on chemical reactions between two low molecular weight species is explained in terms of the thermodynamics of polymer solutions.