Controlled-release systems for agrochemicals using biodegradable block copolymers with low-temperature formability

Abstract

Biodegradable block copolymers composed of poly(1,5-dioxepan-2-one) (PDXO), poly(trimethylene carbonate) (PTMC), or poly(ε-caprolactone) (PCL) with poly(l-lactide) (PLLA) were evaluated as matrix materials for controlled-release pesticide formulations. These polymers can be molded under pressure at low temperatures, allowing incorporation of heat-sensitive agrochemicals without thermal degradation. Clothianidin, a neonicotinoid insecticide, was embedded in these polymer matrices and processed into granule-type formulations. Release studies in aqueous and soil environments demonstrated sustained release over one month, attributed to the gradual enzymatic degradation of the polymer matrices by soil microbes. The formulations maintained pesticidal activity throughout the release period. These results indicate that biodegradable baroplastic copolymers are suitable carriers for controlled-release agrochemicals, offering both environmental compatibility and functional performance. Their pressure-induced processability and biodegradability make them a promising alternative to conventional non-degradable plastics, enabling long-term efficacy while reducing environmental impact and supporting sustainable agricultural practices.