HYDROLYSIS OF SIMAZINE UNDER ALKALINE CON DITIONS

The kinetics of chemical hydrolysis of simazine (2-chloro-2,6-bis (eth ylamino)-1,3,5-triazine) was investigated under alkaline conditions. T he rate constants (k) and half-lives(t(1/2)) were determined, and then activation energy (E(a)) of hydrolysis of simazine was calculated. Si mazine was easily hydrolyzed in NaOH solution. The hydrolytic rate inc reased with raising the reaction temperature and increasing the amount of NaOH. The rate constants(k) at 60, 70 degrees C and 80 degrees C w ere 0.0684(s(-1)), 0.127(s(-1)) and 0.236(s(-1)), respectively. The ha lf-lives(t(1/2)) at 60, 70 degrees C and 80 degrees C were 10.13(h), 5 .46(h) and 2.94(h), respectively. The activation energy (E(a)) of hydr olysis was 6.04 x 10(4)(J mol(-1)), this value agreed with the one cal culated by Burkhard et al. Simazine would be hydrolyzed by the mechani sm as flows; chloro substituents linked to triazine ring are reacted w ith by hydroxide ions to form hydroxy substituents. The liberated chlo ride ions are reacted with water, so that hydrochloric acid is formed. The resulted hydrochloric acids are neutralized by NaOH.