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通过全天然产物蓖麻油酸酐(RAN)与羧甲基壳聚糖(CMC)的酰化反应,合成了羧甲基壳聚糖接技蓖麻油酸(CMC-g-RA)共聚物。探讨了原料的相对分子质量、RAN与CMC分子上氨基的物质的量之比、反应温度和溶剂等因素对产物取代度的影响。以CMC-g-RA为载体,通过在中性水中自组装大分子胶束的增溶作用,与植物源农药鱼藤酮(Rot)一起制备了一种新型的农药纳米粒子水分散剂。对其粒径、粒径分布、表面电荷、形态结构和Rot的负载率等物理性能进行了表征,探讨了CMC-g-RA和Rot溶液的浓度对纳米粒子各相关性能的影响。结果表明:所形成的纳米粒子干燥后外观形态呈密实光滑的球状,粒径在200～500 nm之间,具有较窄的粒径分布,表面带负电荷;该纳米粒子的Zeta电位值随CMC-g-RA和Rot质量浓度的升高而增大,在-40～-70 mV之间;Rot的负载率在20%～68%范围内。研究表明,改变Rot和CMC-g-RA溶液的质量浓度配比,可调节纳米粒子的物理性能;控制农药的负载率,有助于调控该新型制剂速效与缓释之间的关系。
Carboxymethyl chitosan-ricinoleic acid (CMC-g-RA) copolymer was synthesized by the acylation of all natural product ricinoleic anhydride (RAN) with carboxymethyl chitosan (CMC) The effects of the factors such as the relative molecular mass of raw materials, the ratio of the amount of amino groups on the RAN and CMC molecules, the reaction temperature and the solvent on the degree of product substitution were discussed. CMC-g-RA was used as a carrier to prepare a novel pesticide nanoparticle water dispersant along with rotenone (Rot), a plant-derived pesticide, by solubilization of self-assembled macromolecular micelles in neutral water. The physical properties such as particle size, particle size distribution, surface charge, morphology and Rot loading were characterized. The effects of concentration of CMC-g-RA and Rot solution on the relative properties of nanoparticles were discussed. The results showed that the morphology of the nanoparticles was smooth and spherical after drying. The size of the nanoparticles was in the range of 200-500 nm with a narrow particle size distribution and the surface was negatively charged. -g-RA and Rot mass concentration increases, between -40 ~ -70 mV; Rot load rate in the range of 20% to 68%. The results showed that changing the mass concentration ratio of Rot and CMC-g-RA solution can adjust the physical properties of nanoparticles. Controlling the loading rate of pesticides can help to control the relationship between the rapid-acting and the slow-release rate of CMC-g-RA.