Peparation And Characterization Of Polymer Carrier

As drug carriers, polymers can absorbe, encapsulate or disperse drugs in the polymers or in the micelles formed by polymers to form nano-drugs. As drug carriers, polymers have many advantages. First of all, the polymers particle sizes are small, which usually distributed between 50 nm to 200 nm. And because of its narrow size distribution, the nano-drugs can easily pass though the endothelial cells to get to some drug targets, which are hard to get to by some tranditional pharmaceutical preparations. Then a novel administration route was stublished. Secondly, the modification on the surface of polymer can endow polymer carriers with the similar core-shell structs with native protein or virus. It makes the nano-drugs not be phagocytosed by the reticular endothelial cells, easily. And the tranditional pharmaceutical preparations are easily be phagocytosed by native protein, and the nano-drugs avoid these disadvantages. Therefore, the nano-drugs can cycle in the blood for a long time. So, the dosage and administration frequency are decreased, and the utilization ratio is increased. In the present, the studies of polymer carrier are mainly concentrated in drug carrier. And the applications on pesticide formulations are rare.The polymer nano-particles were prepared by emulsion polymerization method, utilizing MA, EHMA and MAA as monomers at the temperature range 80-82℃. The monomers molar rato is MA/EHMA/MAA=5/5/3. And the dosage of emusifer is account for 6 % of the systerm. The prepared nano-particles were modified by MA. And the surface carboxylic groups were increased from 38.2 percent to 67.51 percent.The average particle diameters of nano-particles were charactered and confirmed that the polymer emulsions contain nano-particles of approximately 70 nm in diameter. The viscosity-average molecular weight is approximately 3×104 and resulted nano-particles were random copolymers. The resulted polymer having enhanced hydrophobicity improved the thermal stability of copolymer. A new acetochlor EW was prepared through this acrylate polymer carrier. And the distribution of acetochlor in the acrylate polymer carrier was also studied. The results showed that acetochlor EW was stirred at the rate of 2.0×104 r/min for 10 min having much better stability. Entrapment efficiency was also calculated and results confirmed that over 90 percent of acetochlor was encapsulated in the polymeric micelle. Therefore the stability of acetochlor EW was improved.In the experiment, the usage of the acrylate polymer carrier was widened. They not only used in drug carrier but also can be applicated in chemical fertilizer and pesticide preparations. The new acetochlor EW prolonged pesticide effect, reducing the dose of acrylate in application. And it attained the expected purpose of avoiding waste, reducing the usage of organic solvent, reducing the toxicity of pesticide and applying more easier.