Studies on the Surface Properties of Alcohol Ethoxylate and the Application in Suspension Concentrate

Abstract

The paper studies the critical micelle concentration(cmc),the equilibrium surface tension(γcmc),the standard free energy of micellization(ΔGm),the area per molecular at cmc(Acmc) and hydrophile lipophile balance(HLB),which are affected by the function of the oxyethylene group( EO) number in the alcohol ethoxylate(AEO). It also studies the influence of AEO with different EO number as dispersants on the rheological properties(viscosity,storage modulus G',γflowand thixotropy) and the physical stability( the suspension rate before and after the hot storage,residual pourability ratio) of Mancozeb(25%) suspension concentrate(SC). As the value of the oxyethylene group number increase from 4 to 20,the values of cmc,γcmc,ΔGm,Acmcand HLB are rising. The adding of AEO can reduce the viscosity of Mancozeb(25%) SC,and the SC with AEO-9 has the lowest viscosity. With the increase of the EO chains in AEO,the thixotropy recovery of SC which has higher residual pourability ratio decreases gradually. Through strain sweep,we find the values of G' and γflowreflect the structural variation of the SC,and then G' and γflowcan be used as suitable SC stability indicators.