Preparation and characterization of polymeric films from Polyvinyl Alcohol (PVA) / Methylcellulose (MC) for the controlled release of the agrochemical Terbuthylazine

Abstract

In the last decades, the development of matrices for incorporation of bioactive species employing polymers as carriers has been gaining ground particularly as a potential device for the controlled release of these species due to the bioavailability, good matrix association with bioactive species and lower toxicity of the polymers . In the agrochemical area, processes of photodegradation, leaching and surface migration reduce the efficiency of agrochemicals. The industrial agriculture practiced in Brazil is based on the intensive use of pesticides and herbicides. One approach to minimizing herbicide transport losses, prolonging the time of action, and reducing toxicity, after soil application is the use of controlled release formulations, whereby the herbicide is delivered gradually over time, thus limiting the amount immediately available for transport processes. In this work, the controlled release of the herbicide Terbuthylazine (TBA) was studied using the PVA / MC polymer blend. Infrared spectra show that there was a mixture of polymers and that MC was more pronounced in the films. The release was rapid in the first 10 minutes of assay, thus showing that the PVA / MC blende is a potential polymeric matrix for controlled releases of agrochemicals in soil.