新型功能化生物降解农药载体材料的制备与药物控释的研究

In the pesticide processing field, microcapsule technology is an important and difficult problem in the world. Exploitation of competitive polymer wall is an important topic of contemporary pesticide microcapsule. A novel functional and biodegradable polymer as pesticide carrier will be prepared using carbon dioxide. The poly(propylene carbonate) is obtained by copolymerization of carbon dioxide with propylene oxide. The biodegradation rate and thermal stability of PPC will be improved by introducing maleic anhydride, which has the water affinity. Under the optimal conditions of the process terpolymerization, an aliphatic polycarbonate poly [(propylene oxide)-co-(carbon dioxide)-co-(malefic anhydride)] (PPCMAH) will be successfully synthesized. The polycarbonate has a hydrophobic segment and a hydrophilic one. A pesticide carrier material with pore structure will be prepared by using pore formed technique. The PPCMAH-pesticide microcapsules will be prepared by the water-in-oil-in-water multiple-emulsion method. The factors, which could obviously impact on the carried-drug capability of PPCMAH, will be studied systematically. We expect to elucidate the relationship between structural feature and spesticide release of these materials on higher administrativelevels. Research results will be helpful for making pesticide microcapsules production and providing a basis for quality standards. It makes contribution for modernize, internationalizing pesticide microcapsules.

农药微胶囊技术已成为国际上农药制剂加工领域的热点与前沿，开发有竞争力的高分子囊壁材料是当前农药微胶囊研究的一个重要课题。本课题以二氧化碳为基础原料制备新型功能化生物降解农药载体材料。拟通过含有亲水性极性基团顺丁烯二酸酐的引入，来改善由二氧化碳和环氧丙烷的共聚物聚亚甲基碳酸酯的降解性能，并改善其热稳定性能。通过对聚合反应条件的优化，制备一种既含有亲水链段又含有疏水链段的生物可降解脂肪族聚碳酸酯-聚[碳酸(亚丙酯-co-顺丁烯二酸酐)酯] (PPCMAH)。再利用致孔技术制备具有微孔结构的农药载体材料。采用复相乳液(W/O/W)溶剂挥发法制备PPCMAH载农药微胶囊，并对其载药性能和释药性能进行系统的研究。本课题拟从更高层次上阐明材料的结构与其对农药控释之间的关系，同时为制定合理农药微胶囊工艺和质量标准提供科学依据，为农药微胶囊现代化、国际化做出更大贡献。

本项目针对全国乃至全世界关注的焦点，即农药残留造成的对农产品的污染进而影响到人类的生活质量问题，开展了生物可降解农药载体材料的应用基础研究。以二氧化碳为基础原料合成了一系列载农药控释材料，并通过红外光谱和核磁共振谱，凝胶液相色谱等方法和手段对其结构进行分析。以吡虫啉为模型药物，采用复相乳液溶剂挥发法制备了新型功能化生物可降解农药微胶囊，并利用光学显微镜、扫描电镜、透射电镜、粒径仪等测试分析技术对其微观形貌进行了分析，研究了载农药微胶囊的载药性能和释放动力学行为，明确了载农药微胶囊的制备工艺，初步建立了聚合方法-材料结构-粒子微观结构-微胶囊性质之间的关系模型。结果表明，载农药微胶囊的理化特性由制备工艺决定，其结果决定了其生物效应和环境效应；载农药微胶囊的缓释特性与材料的结构、产品的粒径和环境均有关系；与传统制剂相比较，载农药微胶囊具有较好的生物效果和持效期，且生物效果可通过优化制备工艺得到较好的实验结果；载农药微胶囊与传统制剂相比较具有较小的环境毒性。其研究成果将为新型高效农药微胶囊的开发研究和科学使用提供新的思路和方法，对农业可持续发展及农产品与生态环境安全具有重要意义。