Controlled-release Formulations of Trifluralin Herbicide by Interfacial Polymerization as a Tool for Environmental Hazards

Trifluralin is a widely used herbicide that can be an environmental hazard due to its sensitivity to photodegradation and volatilization to the atmosphere. Using modern techniques, such as microencapsulation, may help maintain trifluralin activity for an appropriate period and reduce applications' quantity and frequency. This work aimed to develop controlled-release formulations of trifluralin by microencapsulation of the active ingredient using interfacial polymerization. The successful encapsulation of trifluralin in the polyurethane network was confirmed by IR and 1HNMR spectroscopy, showing the two compounds' corresponding signals. Dissipation of trifluralin in the microencapsulation and EC formulations were tested with the herbicide exposure to UV light in a reactor for 0, 2, 4, 6, and 8 h. The results showed that the formulation significantly affected herbicide dissipation (P≤0.01). With increasing UV exposure, the active ingredient in the EC formulation decreased linearly and reached 43% after 8 h. In comparison, only 0.9% of the initial herbicide level in the microencapsulation was lost during the same time. Our results indicated that an effective herbicide such as trifluralin can be protected from volatilization and photodegradation by developing a microencapsulation formulation.