Evaluating the Adhesion of New Spreader-Sticker Adjuvants
SourceSpreader-sticker adjuvants are commonly used in agrochemical formulations to enhance the coverage, adherence, and rain-fastness of active ingredients on plant leaf surfaces. They typically combine a spreading agent that lowers the surface tension of the water droplets with a “sticker,” which can be a synthetic polymer, biopolymer, latex, or polyterpene, to prevent the rapid wash-off of the active ingredient. The spreader parts of the adjuvants are fairly consistent from one product to another and typically consist of alcohol ethoxylates used to lower the contact angle between the droplets and the leaf surface. The sticker portion depends on the specific product, however, and different compounds are used in the industry. This study examines a new class of sticker polymers based on poly(oxyalkylene) polyamides and the effect of molecular structure, active ingredient, and formulation on their adhesiveness.