Interactions of anionic surfactants and polymers used as spray tank adjuvants

摘要

Interactions between some water-soluble polymers used as spray drift control additives in spray tank mixes and a range of anionic, sulfonated surfactants were investigated. Changes in the shear viscosity of the solutions were used as an indicator of investigated. Changes in the shear viscosity of the solutions were used as in indicator of investigated. Changes in the shear viscosity of the solution were used as an indicator of interactions. Anionic polymers showed no viscosity increase with any of the sulfonated surfactants. SOme non-ionic polmers, notable poly(enthylene oxide) (PEO), poly(vinyl alcohol) and poly(vinyl pyrrolidone) showed marked increases in viscosity in semi-dilute solutions. The extensional viscosity of very dilute (1-1000ppm) solutions of PEO, was determined by pressure and flow rate measurements in a packed bed. Extensional viscosity increased by a factor of up to 10 with added soudim dodecyl benzene solfonate (NaDDBS). The droplet size distributions of the solutions sprayed hrough an agricultural spray nozzle were deterined, using as exmaples PEO solutions of varying moolecular weigth, with and without NaDDBS. The droplet size distributions increased with increasing extensional viscosity. Similar experiments with anionic polymers demonstrated that the droplet size correlates with extensional viscosity, and not with shear viscoity.