制备工艺对丁硫克百威微囊理化特性的影响

以水为介质,以脲醛树脂为壁材,采用原位聚合法制备了20%丁硫克百威微囊悬浮剂,并分别讨论了乳化剂种类、芯壁质量比、固化条件等因素对微囊形态、粒径大小及其分布、以及包封率的影响。结果表明:乳化剂1602#与500#的质量比为15 ∶2(质量分数为6%),芯壁质量比为1 ∶1,并以质量分数为1%的壳聚糖为甲醛吸附剂,2%的聚硅氧烷为改性剂,5%的硫酸铵溶液为酸度调节剂,60 ℃下固化2 h,制备出的丁硫克百威微囊外观形态良好、平均粒径2.00 μ m、粒径分布均匀,包封率大于90.9%以上,悬浮率大于92%。该微囊悬浮剂稳定性高,具有较好的开发应用前景。

The effect of preparation procedure on physico-chemical properties of carbosulfan microcapsules

Microcapsules containing carbosulfan with urea-formaldehyde (UF) were prepared by the in situ polymerization method in aqueous medium.The properties of carbosulfan microcapsules were analyzed with emulsifier,rate of pesticide and wall,temperature,acidifying agent,adsorbent agent of formaldehyde,modifier.According to the results,optimum reaction conditions were as follows:emulsion 1602# ∶500#=15 ∶2(m/m),carbosulfan ∶ UF=1 ∶1(m/m),the dosage of emulsifier were 6.0%,5%(NH4)2SO4 as the acidifying agent,1% chitosan as the adsorbent agent of formaldehyde,2% polysiloxane as the modifier.Under these conditions,the microcapsules showed satisfied surface morphology and particle size distribution,with the mean particle diameter of 2.00 μ m,and encapsulating rate was above 90.9%,suspension rate was above 92%.The 20% carbosulfan microcapsule suspension has the characteristics of high stability,and possesses a good potential for its development.