利用酚醛环氧树脂-丙二胺聚合物制备高效氯氟氰菊酯微囊

探索了以酚醛环氧树脂-二元胺聚合物为壁材制备高效氯氟氰菊酯微囊(CS)的可行性，明确了酚醛环氧树脂用量及乳化剪切转速等因素对微囊基础物化特性以及药剂释放性能和应用效果的影响。利用油溶性单体酚醛环氧树脂与水溶性单体丙二胺，在油-水界面上发生聚合反应形成不溶于水的聚合物，制备得到高效氯氟氰菊酯微囊。通过光学显微镜和扫描电子显微镜观察其形貌；利用红外光谱仪分析囊壁结构；采用气相色谱法分析微囊的载药量、包封率和释放性能；经粒度分析仪测定平均粒径和粒度分布；最后采用浸叶法测定了该载药微囊的杀虫活性。结果表明:所得高效氯氟氰菊酯微囊为规则的球形，囊壁表面光滑无孔洞且伴有少量褶皱。随酚醛环氧树脂用量增加，微囊平均粒径增大，载药量下降，释放速率降低，而包封率变化不大。随乳化剪切转速增加，平均粒径下降，释放速率加快。采用优化条件制备所得微囊的平均粒径为21.33 μm，包封率为91.04%，载药量为43.97%。其释放动力学表现为:0~15 min内为快速释放阶段，累计释放量达到78.01%；15~240 min为缓慢释放阶段，在240 min时累积释放量达97.04%。4种不同粒径(2.78、5.19、11.86和23.15 μm)高效氯氟氰菊酯微囊和同剂量高效氯氟氰菊酯乳油对小地老虎幼虫的毒力测定结果表明:随着微囊粒径的减小，其毒力逐渐增大(LC50值分别为16.44、23.33、29.36和37.57 mg/L)，但不同粒径微囊处理组毒力均略低于乳油(LC50值为10.41 mg/L)。研究表明，可采用酚醛环氧树脂-二元胺聚合物为壁材制备高效氯氟氰菊酯微囊，速效性好且活性易调控，在农药微囊剂制备中具有很好的应用前景。

Lambda-cyhalothrin microcapsule prepared with 1,2-diaminopropane modified novolac epoxy resin by using interfacial polymerization

lambda-cyhalothrin-loaded microcapsules were prepared with diamine modified novolac-epoxy resin as wall material. The influences of novolac-epoxy resin amount and shearing rate on their properties, such as basic physicochemical parameters, release profiles and application properties were also investigated. The lambda-cyhalothrin microcapsules were prepared by interfacial polymerization of an oil-in-water emulsion which contained an oil-soluble novolac epoxy resin and water-soluble 1,2-diaminopropane. The microcapsules obtained were characterized by optical microscope and scanning electron microscopy. The structure of the polymer was analyzed using the infrared spectrometer. The loading capacity, encapsulation efficiency, and the release performance were analyzed using gas chromatography. The average particle size and distribution of microcapsules were detected by a laser particle size analyzer. The insecticidal activity of lambda-cyhalothrin microcapsules was determined using leaf-dipping method. The microcapsules were regular spherical particles, all of which displayed smooth surface without holes and accompanied with tiny wrinkles. With the increase of the content of novolac-epoxy resin, the average diameter of the microcapsules increased, the loading capacity declined, the release rate decreased and the encapsulation efficiency did not change significantly. The results also showed that the average diameter of the microcapsules decreased and the release rate increased with the shearing rate. As for the microcapsules prepared under the optimal conditions, the average particle size of the sample was 21.33 μm, encapsulation efficiency was 91.04% and the loading capacity was 43.97%. The microcapsules released fast in the first 15 min and reached a cumulative release rate of 78.01% in the first 15 min. Then they released much slower in the period between 15 min and 240 min, with cumulative release rate of 97.04% in the first 240 min. The lambda-cyhalothrin-loaded microcapsules with different particle sizes (2.78, 5.19, 11.86 and 23.15 μm) also displayed favorable insecticidal activities against Agrotis ypsilon (with the LC50 of 16.44, 23.33, 29.36 and 37.57 mg/L), although they had slightly lower toxicity compared with that of emulsifiable concentrate treatment (LC50 was 10.41 mg/L). Microcapsules fabricated with diamine modified novolac-epoxy resin exhibited rapid effectiveness and tunable bioactivity which make them potential candidates in pesticide formulations, especially microcapsules.