Effects of polymer composition and viscosity on droplet size of recirculated spray solutions.

摘要

Tests were carried out on 12 polymers used in commercial drift retardants to determine shearing effect on physical properties and sprayed droplet size distributions. A shear test stand which simulated agricultural sprayers was used. Polymers including polyethylene oxides, polyacrylamides, and a polysaccharide, with a range of molecular weights, anionicities and concentrations were tested. Droplet sizes of all samples decreased with increasing recirculation. Increasing concentration and molecular weight increased droplet sizes of unsheared spray samples for non-ionic and anionic polymers. Most polymer based drift retardants lose effectiveness after recirculation through agricultural sprayers, but degradation varies greatly with polymer type.