利用阿维菌素具有2个活性羟基的特性,设计合成了一种具有阿维菌素结构单元的阴离子型聚氨酯分散剂,采用核磁共振和红外光谱表征了其结构.利用分散剂与阿维菌素结构的相似性,将溶有阿维菌素的分散剂溶液加入水中,制备了阿维菌素的纳米水分散体.研究分散剂中羧基含量及其分子量对分散体粒径的影响,结果表明,随着羧基含量的增加,分散体粒径逐渐降低,适当控制分子量有助于改善分散剂的分散能力.透射电镜显示分散粒子具有近似球形的形貌,粒径在20~40 nm之间.纳米分散体具有较高的离心稳定性和稀释稳定性.
Two reactive hydroxyl groups made avermectin a component to prepare anionic polyurethane disper- sant containing avermectin structure units. The structure of the resulting dispersant was characterized by 1H nuclear magnetic resonance spectrometer and infrared spectrometer. Based on the structural similarity be- tween the dispersant and avermectin, avermectin nano aqueous dispersion was fabricated via addition the solu- tion of dispersant and avermectin into water. The influences of carboxyl content and the molecular weight of the dispersant on the particle size of the dispersion were investigated. The results indicated that smaller parti- cles were obtained at higher carboxyl content and the dispersing ability was affected by the molecular weight of the dispersant. The transmission electron microscopic image of the dispersion revealed that almost spherical particles with most of the size in the range of 20-40 nm were formed. Moreover, the dispersion displayed high centrifugal stability and dilution stability.