The Study Of Aqueous Acrylic Acid Resin Film-coating And Redispersible Polymer Powders

In the medicine tablet or the capsule surface, the macromolecular material for pharmaceutical coating can form very thin elastic membrane ,which could be dissolved under a certain pH value,time or position in person body. Pharmaceutical coating has the features of controlled release and protection. The acrylic polymer is the most common used pharmaceutical coating material,which was security, stability , non-stimulation and etc. There are three kinds of pharmaceutical coating material because of its dissolved pH value, i.e. the enteric acrylate resin, the stomach acrylate resin and the osmotic acrylate resin.We have studied the emulsion polymerization process of enteric acrylate resin, using the methyl acrylic acid and the methyl methacrylate as the monomers, and stomach acrylate resin , using methyl methacrylate and 2-(dimethylamino) ethyl methacrylateas as monomers.The former was prepared using sodium dodecyl sulphate and tween-85 as emulsifier,the latter using cetyltrimethyl ammouium bromide and OP-10 as emulsifier. The effects of dosage, species of emulsifier, initiator, relative molecular mass modulator, reaction temperature, speed of stirring and the way of feeding on the process were investigated in detail.At last, we have got The best emulsion polymerization craft. There are no organic solvents in the polymerization process.The acrylate resin's relative molecular weight was determined with Ubbelodhe viscosimeter. The morphology of the prepared emulsion was studied with IR. The checking datums were shown that the acrylate emulsion accords with the criterion of Pharmacopoeia of People's Republic of China, and provided for the reference of the acrylate resin industrialization production. This thesis provided the best preparation technological process of the dispersible emulsion powder's mother liquor and the spray drying conditions was mastered well.The mother liquor was prepared using two kinds of method, ie, core/shell-emulsion polymerization and using protective colloid in normal emulsion polymerization process. The stability of redispersible latex powder liquor was determined and various factors of affecting latex properties were discussed. After the scanning electron microscopy test, functional groups and their size distribution were analysised detailed. The results showed that the prepared powder can be easy dispersed in water. The redispersible latex powder is a kind of thermoplastic resin, low-strength material; its solution is a two-way system, mixed with water for re-emulsification, and has the same properties with the original latex.