Lignin‐polyethylene glycol matrices and ethylcellulose to encapsulate highly soluble herbicides

Abstract

The blending of lignin with polyethylene glycol (PEG) allowed us to obtain formulations with controlled release properties in which metribuzin have been successfully trapped with encapsulation efficiency higher than 85%. Moreover, the modification of the lignin's viscoelastic properties by the addition of PEG led to obtain herbicide formulations with active ingredient contents lower than 15%, suitable for its application in soil. Fourier transformed infrared spectroscopy and differential scanning calorimetry studies indicated the compatibility between polymers and metribuzin in lignin-based controlled release formulations (CRFs). Lignin-based formulations were coated in a Wurster-type fluidized-bed equipment using ethylcellulose and dibutylsebacate. Scanning electron microscope pictures showed a homogeneous film in ethylcellulose-coated CRFs. The kinetic release studies showed that the release rate of metribuzin was mainly controlled either by selecting the granule size of controlled release lignin-PEG matrixes, or by changing the thickness of coating film for ethylcellulose coated CRFs. These results could help to increase the efficiency of delivery of the highly soluble herbicide metribuzin and prevent the environmental pollution derived from its use. V C 2014 Wiley Periodicals, Inc. J. Appl. Polym.Sci. 2015, 132, 41422.

Constructing Slow-Release Formulations of Metribuzin Based on Degradable Poly(3-hydroxybutyrate)

“…Because of these reasons, metribuzin is an appropriate herbicide for use in controlled delivery systems. By now, it was described developing slow release metribuzin formulations with different natural and synthetic materials, ,,− which should enable slow release of an active component, be fully biodegradable in the environment, and have a reasonable price.…”

Stability Phenomena Associated with the Development of Polymer-Based Nanopesticides

“…This versatile polyether is being utilized in various applications. For example, Fernández-Pérez et al reported that the combination of lignin and PEG for metribuzin delivery is a suitable formulation for soil applications, exposing a high encapsulation percentage [ 40 ]. Carbofuran is another insecticide that has been entrapped in PEG nanostructures, exhibiting a sustained release between 21 and 49 days, depending on the PEG molecular weights [ 41 ].…”

Plant Innate Immune Response: Qualitative and Quantitative Resistance

“…The cross-coupling reaction of monolignols forms phydroxyphenyl, guaiacyl, and syringyl lignins. These, and also lignans, are deposited to enforce secondary cell walls, thus preventing pathogen spread mainly through stem and rachis of inflorescence (Fern andezÀP erez et al, 2015;Niks et al, 2015). Hydroxycinnamic acid amides (HCAAs): Hydroxycinnamic acid amides are produced as polymers of amines and hydroxyphenols, in several combinations (Figure 3) (Dong et al, 2015;Kusano et al, 2015;Wen et al, 2014;Yogendra et al, 2015a).…”