Evaluation of phosphosuccinate ester sodium salts as next-generation wetting agents for agrochemical water-dispersible granules (WDG)

Water-dispersible granules (WDGs) are commonly utilized agrochemical formulations due to their dust-free handling, quick dispersion, and enhanced operator safety; nevertheless, their efficacy is significantly influenced by the selection of wetting agents. This study systematically evaluated a series of phosphosuccinate-based wetting agents, specifically mono-ester (MEPS) and di-ester (DEPS) derivatives with octyl and ethylhexyl chains, as alternatives to the conventional sulfosuccinate surfactant dioctyl sodium sulfosuccinate (Multiwet™ 8269) in a Pymetrozine 50% WDG formulation. In the current study, WDGs were prepared using a wet granulation-extrusion procedure, and their surface-active properties were evaluated through surface tension measurements and interfacial parameter calculations. Using standard CIPAC methodologies, we looked at the formulation’s performance by checking its dispersibility, suspensibility, wet sieve residue, particle size distribution, zeta potential, foaming behavior, and spray-tank compatibility at room temperature (25 °C), cold (0 °C), and accelerated (54 °C) storage conditions. Throughout the trial, all of the formulations showed good physical stability, a consistent appearance, and a steady pH. Phosphosuccinate-based solutions showed better dispersion efficiency, less non-dispersible residue, better electrokinetic stability, and significantly reduced persistent foam formation than the benchmark. Structure property correlations showed that the functionality of esters and the structure of alkyl chains are very important for how things stick to surfaces and how granules break down. In general, the results show that phosphosuccinate wetting agents are good substitutes for traditional sulfosuccinates in high-performance WDG formulations that work better with spray tanks.