農藥製劑改良之研究

Study on Improvement of Pesticide Formulation

秦志平(Chih-Ping Chin)

指導教授 ： 吳和生

元智大學/工程學院/化學工程與材料科學學系/博士(2012年)

摘要

由於人口增長、人們收入增加和不斷增長的糧食消費，導致全球糧食需求將繼續增加。雖然在過去一個世紀內，糧食產量也隨之大幅度上升。糧食產量的增加能否跟上日益增加的糧食需求，仍是充滿變數。農藥作為植保產品，對於提供社會大眾高品質且價廉的食物供應上，有著極大的貢獻。因此，使用農藥是有其必要性和無法避免的。 也就在農藥的協助下，農民得以在有限的土地資源上獲得最大的糧食產量。
有鑒於現今在新藥的篩選和合成上變得日益困難並消耗大量的成本，所以在農藥製劑和加工技術上進行開發展和改良以便能將現存之農藥做最大限度地利用亦是農化產業重要的發展趨勢。儘管如此，現今常用的農藥製劑存在有一些問題，諸如：低效、使用不便及具有環境風險。隨著農化產業的發展和公共環境的要求，開發新型藥物輸送系統或改進現存的劑型以達到高效、安全、操作方便和環保的目的，是為現今植物保護產品的發展趨勢。
本研究分為三個主題進行討論。首先，於水懸劑(SC)實驗中，利用奈米技術製作一新型製劑，即奈米水懸劑，並將此與市售一般水懸劑進行比較。實驗結果證明，納米水懸劑在相同的劑量下具有較高的藥效 (藥效提升13.5%)，其物理和化學性質的穩定度可達2年，符合市售產品標準要求。再者，為了改良現存乳劑(EC)的缺點，我們使用生物柴油做為乳劑中的替代溶劑。實驗結果表明，它不僅是穩定的商業配方，更能使有效成分有效分布於目標作物上，從而增進藥效(藥效提升28.9 %)並延長作用時間，並可大幅降低施藥頻率。原體及溶劑所產生的不好味道並可藉由生質柴油低揮發性的特性得以改善。此外，由於生質柴油具生物可分解、生物適應性及高閃火點等特性，使得該製劑與一般市售乳劑相較之下，是為一環保、低毒及安全的劑型。
最後，在微乳劑（ME）的改良上，我們亦使用生質柴油取代其中之石化類有機溶劑。實驗結果證明，使用生質柴油做為溶劑應用於微乳劑製劑工程上，亦可得良好的微乳製劑。對於油溶性的固態農藥原體，使用生質柴油做為溶劑可有效擴大微乳劑均勻相區域(O/W及W/O)的面積，有效形成微乳劑。由性能試驗結果得知，生質柴油做為溶劑除透明度較低外，在物理和化學性質的穩定度上與市售微乳劑相等。由於生質柴油具有較好的耐溫性質，故可增加微乳劑存放的穩定度。且由藥效實驗結果得知，使用生質柴油之微乳劑，其藥效亦有顯著提升，提升幅度為13.1%。此外，以生質柴油將有害之石化類有機溶劑取代，可使微乳劑成為低風險和低毒性的安全劑型。

關鍵字

生物可降解 ； 農藥製劑 ； 微乳劑 ； 奈米懸浮液 ； 乳劑

並列摘要

Because the food demand is increased as a result of population growth, increased incomes and growing consumption of food. Although the world food production was also rose substantially in the past century. It is uncertain whether the yield increases in food production can be achieved to keep pace with the growing food demand. Crop protection products, pesticides, contribute to the production of a stable and predictable supply of high quality and affordable food. Therefore, the application of pesticides is becomes necessary and inevitable. With the help of pesticide, farmers can secure the maximum outputs of crop production from the limited land we have available.
Because the screening and synthesis of new active ingredients become more difficult and costly rising in the present days, the development and improvement in pesticide formulation and process technology are the important for maximum use of existing active ingredients. However, the existed pesticide formulations have some problems such as: inconvenient and unsafe to use, low efficacy, and potential environmental risks. As the development in agrochemical industry and popular environmental requirements, developing novel delivery system or improving the existed pesticide formulations with high efficacy, safe and convenient in operation and environmental friendly are trends in modern crop protection products.
There are three topics are discussed in this study. First, a nano-suspension as a novel delivery system by using nano technology was proposed in improving of suspension concentrate (SC) formulation. The experimental results indicated the nano-suspension has the higher efficacy (13.5% increased) at same dosage which was compared with a commercial product. The nano-suspension system acted in physically and chemically stability over a period of 2 years. Second, to improving the disadvantages of existed emulsifiable concentrate (EC) formulation, the biodiesel was proposed as a substitute carrier used in emulsifiable concentrate formulation. The experimental results showed that the biodiesel formulation was not only obtained as stable as commercial formulation but also increasing the residual of pesticides (28.9% increased), thus the efficacy was increased with a longer lasting time and the frequency of application was also reduced. Offensive odors from active ingredients and solvents can also be suppressed because of the low vaporization of biodiesel. In addition, the emulsifiable concentrate with biodiesel is becoming friendly to environment, low toxicity and safer in warehousing due to its natures of biodegradable, bio-compatibility and high flash point.
Finally, biodiesel was also conducted to replace petroleum-based solvents in microemulsion (ME) formulation. The experimental results demonstrated that good pesticide microemulsion can be prepared with biodiesel as the solvent. Furthermore, using biodiesel as a solvent for solid, oil-soluble active ingredients in pesticide microemulsion formulations can effectively increase the areas of the single-phase microemulsion regions (O/W and W/O) and allow the easier formation of microemulsions. The results of performance test, for the selected formulations, showed no significant difference between the biodiesel and commercial formulations, expect for a lower transparency. The biodiesel formulation is as stable as the commercial formulation with petroleum-based solvents. Because of its broader transparent temperature range, biodiesel increases the stability of the formulation in storage and transportation for a variety of environments. The experimental results indicated the biodiesel formulation has the higher efficacy (13.1% increased) at same dosage which was compared with a commercial product. In addition, the ME formulation with biodiesel also becomes friendly to environment, low toxicity and safe for user as compared to commercial formulation.

並列關鍵字

Emulsion concentrates ； Biodegradable ； Pesticide formulation ； Microemulsion ； Nanosuspension

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