基于聚碳酸亚丙酯载体的农药微胶囊制备与表征

Preparation and characterization of pesticide microcapsule based on the poly(propylene carbonate) carrier

采用阴离子配位聚合法,以高聚物负载型双金属氰化物复合体(DMC)作为催化剂,合成了二氧化碳、环氧丙烷二元共聚物:聚碳酸亚丙酯(PPC)。并以聚乙烯醇PVA-1788为水相稳定剂,采用乳化溶剂挥发法制备毒死蜱微胶囊。采用土壤悬浊拟环境培养实验法评价了PPC的降解性能。通过光学显微镜(OM)、扫描电子显微镜(SEM)、广角X射线衍射(W-XRD)、高效液相色谱(HPLC)等表征农药微胶囊的性能。结果表明,PPC具有生物可降解性,所得的PPC-毒死蜱微胶囊球形规整,表面光滑。95%的微胶囊粒径在3～10μm范围内,载药量和包封率分别达到16.75%和89.34%。微胶囊释药性能研究表明,PPC-毒死蜱微胶囊具有明显的缓释效应,其释放可分为前期快速释放和中后期稳定释放2个阶段。释放27d,PPC微胶囊累积释药量达86.87%。

Poly（propylene carbonate）（PPC） was synthesized by anionic coordination polymerization of carbon di- oxide and propylene epoxide,double metal cyanide complexes （DMC） as catalyst. The chlorpyrifos microspheres were prepared by emulsion solvent volatilization method with PVA-1788 as stabilizer. The degradation performance of PPC was evaluated by simulated soil suspension environment experiment. The properties of the pesticide microcapsule were characterized by scanning electron microscope,optical microscope, wide-angle X-ray diffrac- tion spectra and high performance liquid chromatograph. The results showed that PPC was found to be biode- gradable,and the microcapsule had a smooth and spherical surface,and 95% microcapsules was in the range of 3- 10/lm. The drug loading and encapsulation efficiency of PPC-chlorpyrifos microspheres were 16. 75% and 89.34% ,respectively. Study on release effect showed that PPC-chlorpyrifos microcapsule had significant controlled-release effect and release of chlorpyrifos could be divided into early rapid-release stage and later controlled-release stage. The accumulated drug release reached 86.87% in 27days.