An efficient organosilane-modified polycarboxylate dispersant with excellent dispersing performance and superior wettability for tebuconazole suspension concentrate. (29th September 2021) - Zhang, Mingqian
Abstract : The dispersion stability and wettability of suspension concentrates are beneficial for improvement of the utilization rate of pesticides. Abstract : The dispersion stability and wettability of suspension concentrates are beneficial for improvement of the utilization rate of pesticides. Herein, four kinds of novel organosilane-modified polycarboxylate dispersants P(AA3 -APEG1 -Si x ) with different silicone contents ranging from 0 to 0.5 mol were successfully synthesized using acrylic acid (AA), allyl polyethoxyether (APEG-1000) and organosilicon modifier 3-(trimethoxysilyl)propylmethacrylate (MAPTMS) as monomers, and their surface properties were systematically investigated. Meanwhile, 25% tebuconazole (TEB) suspension concentrate (SC) was milled with the four P(AA3 -APEG1 -Si x (SCP(AA3 -APEG1 -Si x ) ), and the influences of P(AA3 -APEG1 -Si x ) on the zeta potential, particle size, suspension rate and rheological behaviors of the 25% TEB SC were also studied. The results showed that P(AA3 -APEG1 -Si0.5 ) had the lowest surface tension by maintaining an AA:APEG-1000 mole ratio of 3 : 1, and changing the MAPTMS additive amount from 0 to 0.5 mol. Additionally, the obtained TEB SCP(AA3 -APEG1 -Si x ) system exhibits shear thinning behavior under high shearing rate, showing typical features of a pseudo-plastic non-Newtonian fluid, which conforms to the Power-law model. More importantly, the SCP(AA3 -APEG1 -Si x ), especially for P(AA3 -APEG1 -Si0.5 ), exhibited relatively minimum change in particle size and zeta potential compared to that of the unmodified polymers, and displayed superior suspension rate. Significantly, TEB SCP(AA3 -APEG1 -Si x ) showed excellent wetting and spreading behavior on plant leaves, which contributes to obviously improving pesticide utilization.