鱼藤酮微胶囊化参数的确定

采用界面聚合法以甲苯-2,4-二异氰酸酯(toluene-2,4-di-isocyanate,TDI)-乙二胺(TDI-乙二胺)为成囊单体制备鱼藤酮微囊悬浮剂,对乳化剂配比、TDI-乙二胺、囊壁-囊芯、分散剂用量、反应pH值、乳化机转速、交联度等因子进行3水平正交优化试验,获得具有高成囊率和较佳恒定释放天数的鱼藤酮微囊悬浮剂制备工艺参数为:乳化剂1210-0204C质量比1∶ 2,成囊单体TDI -乙二胺摩尔比2.5∶ 1,囊壁-囊芯质量比1∶ 1,聚乙烯醇(PVA)在水相中的含量为2.5 mg/g,pH值7.2,转速1 200 r/min、交联度10%。对制备的2.49 mg/g鱼藤酮微囊悬浮剂的成囊率、平均粒径和囊壁厚度、光解稳定性、热贮与低温稳定性及释放速率进行测定,结果表明,以所选定技术参数制备的鱼藤酮微囊悬浮剂具有良好的光解稳定性和优异的控释作用。经125 W人工紫外光照6 d,鱼藤酮微囊悬浮剂的降解率为35.74%,而鱼藤酮乳油则完全降解,鱼藤酮微囊悬浮剂抗光降解性能显著增强;其恒定释放天数为22 d,具有优异的控释作用。

Parameters for Microencapsulation of Rotenone

Interfacial polymerization method using toluene-2,4-di-isocyanate (TDI) and ethylenedi-amine as capsule wall was adopted to prepare rotenone aqueous capsule suspension(CS). Three levels of orthogonal test on emulsifying agents proportion,TDI to ethylenediamine (proportion of mol), capsule wall to capsule nuclear, dosage of dispersant agent, pH, stirring speed of emulsifying and crosslinkage degree were designed to obtain the preparing technology parameters of rotenone CS with highest encapsulation rate and stable release speed. The technology parameters were emulsifier 1210-0204C 1∶ 2 ,TDI-ethylenediamine 2.5∶ 1,capsule wall-capsule muclear 1∶ 1,content of PVA 2.5 mg/g,pH 7.2,stirring speed 1 200 r/min,crosslinkage degree 10%.The critical parameters of 2.49 mg/g rotenone CS such as encapsulation rates, average particle size and the thickness of wall, the stability of photo-degradation, the stability of heating and low temperature storage and releasing speed were determined, and the results showed rotenone CS obtained significant photo-stability and controlling releasing efficiency. Under 125 W artificial ultraviolet radiation for 6 d, the degradation rate of rotenone CS was 35.74%, while the degradation rate of rotenone EC was 100%. The stable releasing time of rotenone CS was 22 d which indicates significant controlling releasing efficiency.