可生物降解聚合物微胶囊的制备与特性

Biodegradable Polymeric Microcapsules:Preparation and Properties

一直以来,可生物降解聚合物被广泛用于各种行业产品中,如包装材料、薄膜制品和生物材料等。可生物降解聚合物的特性与一般聚合物并不完全相同,可采用化学改性、接枝共聚、交联和互穿聚合物网络等技术和不同助剂对聚合物进行改性。虽然这些方法在聚合物改性方面的应用已非常成熟,但化学改性和互穿聚合物网络技术比物理改性复杂。

Biodegradable polymeric microcapsules can be produced through different methods of which emulsion solvent - evaporation/ extraction is frequently used.In this technique,the polymer(often polylactide) is dissolved in a good solvent and is emulsified together with a poor solvent into a nonsolvent phase.The solvent is then removed through the nonsolvent phase by evaporation.This results in solidification of the polymer around an internal droplet of the poor solvent.The poor solvent may be removed later when hollow capsules are required. This paper discusses the fundamental aspects of the formation process of hollow polylactide microcapsules and its effects on the physical and chemical properties of the capsules,with emphasis on the solidification process of the polymer and the resulting properties of the shell.The scope for improvement and adaptation of the current process,including new emulsification techniques,is also discussed. The main message of this paper is that the properties of the capsules can be optimized through the solidification process of the polymer which can be highly influenced by the proper choice of the nonsolvent and oil.Since this field is hardly investigated in literature,there is room for improvement,especially if the capsules can be produced with the newest emulsification technologies that are becoming available.