Institute of Biophysics of Siberian Branch of Russian Academy of Sciences, Federal Research Center "Krasnoyarsk Science Center SB RAS", Krasnoyarsk, Russia.
Siberian Federal University, Krasnoyarsk, Russia.
J Environ Sci Health B. 2021;56(5):467-476. doi: 10.1080/03601234.2021.1911206. Epub 2021 Apr 14.
Different technologies to prepare long term pesticide forms include polymer coating, preparing composites and encapsulating pesticides in nanoparticles. A simple and low-cost method was proposed to obtain slow-release formulations by co-extrusion of a pesticide with a biodegradable polymer at a temperature above the melting points of both components. A herbicide metribuzin and low-melting polyester poly-ε-caprolactone were chosen for this work. Formulations containing 10%, 20%, and 40% herbicide were prepared. During 7 days of their exposition in water, it was released from 81% to 96% of initially loaded metribuzin; the highest release was detected for 40%-loaded forms. Biodegradation of the constructs and pesticide release were further studied in the model soil. Degradation rates of the specimens increased with an increase in pesticide content, from 9% to 20% over 14 weeks for the 10%/20%-loaded and the 40%-loaded specimens, respectively. The release of metribuzin reached, respectively, 37-38% and 55%. The herbicide content in soil was lower due to its partial degradation in soil; it reached 23-25% and 33%, respectively, from initially loaded into the polymer matrix. Release kinetics of metribuzin in water as in soil best fitted the First-order model. The used approach is promising for obtaining long-term release formulations for soil applications.
不同的技术可用于制备长效农药剂型，包括聚合物涂层、制备复合材料和将农药包封在纳米颗粒中。本研究提出了一种简单且低成本的方法，通过在高于两种成分熔点的温度下将农药与可生物降解聚合物共挤出，来获得缓控释制剂。本研究选择了一种除草剂嗪草酮和低熔点聚酯聚己内酯来进行这项工作。制备了含有 10%、20%和 40%除草剂的制剂。在水中暴露 7 天期间，初始负载的嗪草酮中有 81%到 96%被释放出来；在 40%负载的制剂中检测到最高的释放量。进一步在模型土壤中研究了构建体的生物降解和农药释放。随着农药含量的增加，样品的降解速率增加，10%/20%负载和 40%负载的样品在 14 周内分别从 9%增加到 20%。嗪草酮的释放量分别达到 37-38%和 55%。由于部分在土壤中降解，土壤中的除草剂含量较低，分别为初始负载到聚合物基质中的 23-25%和 33%。嗪草酮在水中和土壤中的释放动力学均符合一级模型。该方法有望用于获得用于土壤应用的长效释放制剂。
