Cross-linked Cellulose Ester/Linseed Oil Composites for Controlled Release Fertilizers

Food scarcity is an ever-present concern for a growing population but can be mitigated through innovations in agriculture. Fertilizers are required to produce a sufficient amount of food, and while they contain key nutrients for crop growth, these nutrients can leech into the surrounding environment. Controlled release fertilizers slow the release of nutrients, encasing the prills in a semi permeable coating. Current coatings are non-biodegradable, causing microplastic soil contamination, which is very difficult to remove. Cellulose esters offer a compelling alternative, with an ability to cross-link into thin films that can be applied as coatings. The cellulose esterification was completed using a polar substitution method, allowing much of the reaction to be done at room temperature, eliminating thermal degradation that occurs when using heat activation. Linseed oil serves as a solvent, with its characteristic of polymerizing through auto oxidation. These two components can create a completely biodegradable film that allows for controlled nutrient release without environmental contamination.