Trujillo-Cayado, Luis Alfonso , SANTOS GARCÍA, JENIFER, Calero, Nuria , Carmen Alfaro, Maria , Munoz, Jose
Si
Afinidad
Article
Científica
0.106
0.148
01/01/2013
000319648200008
This study deals with a rheological characterization of a commercial suspoemulsion used for agrochemical application. Steady state flow and low amplitude oscillatory shear (SAOS) behaviour at five different temperazatures in the range of 5 to 25 degrees C are compared. Flow curves revealed that the pseudoplastic behaviour obeying the Sisko model was less pronounced as temperature was increased. Stress sweeps performed at 0.1 Hz allowed to determine the small linear viscoelastic range of the suspoemulsion, which depended on the temperature. The suspoemulsion at the different temperatures studied exhibited the typical weak-gel viscoelastic behaviour under SAOS between 3 and 0.01 Hz. The occurrence of a minimum of G '' allowed to calculate the "Plateau" modulus, which decreased with temperature according to an Arrhenius type equation. Despite of that, the suspoemulsion showed an elastic character, which favoured its physical stability. Also, It has been demonstrated that the system did not follow the Cox-Merz superposition rule.
suspoemulsion; rheology; viscoelasticity; non-newtonian flow; pesticide