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分别制备了以脲醛树脂、密胺树脂、聚氨酯和聚脲为壁材的10%高效氯氰菊酯微囊悬浮剂,采用土壤薄层层析法、紫外光解法和室内自然光照对比法,通过高效液相色谱测定了各微囊悬浮剂在土壤中的迁移以及在紫外光和自然光照下的光解作用。结果表明:在粒径相近的情况下,以水为展开剂时,分别以聚脲、聚氨酯、密胺树脂和脲醛树脂为壁材的微囊悬浮剂的迁移性依次减小;同一壁材的微囊悬浮剂,迁移性随粒径增加而增大;在紫外光照射下,光解速率由大到小依次为高效氯氰菊酯原药,10%高效氯氰菊酯乳油,以及以聚脲、聚氨酯、密胺树脂和脲醛树脂为壁材的微囊悬浮剂,其半衰期分别是2.3、9.4、20.7、39.0、45.8和51.9 h;在自然光照条件下,上述各药剂的半衰期分别是5.8、5.9、6.9、6.7、12.9和17.3 d。将高效氯氰菊酯制备成微囊悬浮剂后其在自然条件下的光解明显低于原药和乳油,可延长其持效期。
A series of 10% beta-cypermethrin microcapsule suspensions with urea resin, melamine resin, polyurethane and polyurea as wall materials were prepared respectively. The soil thin layer chromatographic method, ultraviolet photolysis method and indoor natural light contrast method were used respectively. Chromatography was used to determine the migration of various microcapsule suspensions in soils and their photolysis under UV and natural light. The results showed that the migration of microcapsule suspending agent with polyurea, polyurethane, melamine resin and urea resin as the wall materials decreased with the similar particle size and water as the developing solvent. The microencapsulated suspending agent showed a migration-enhancing effect with the increase of particle size. Under UV light irradiation, the photodegradation rates were as follows: beta-cypermethrin, 10% alpha-cypermethrin, and polyurea, polyurethane, Resin and urea resin as wall material, the half-lives were 2.3, 9.4, 20.7, 39.0, 45.8 and 51.9 h, respectively. Under natural light conditions, the half-lives of the above agents were 5.8, 5.9, 6.9, , 12.9 and 17.3 d. The cypermethrin cypermethrin prepared into microcapsule suspension after its photoperiod under natural conditions was significantly lower than the original drug and EC, can extend its persistence period.