Formation of polymeric microspheres using electron beam radiation
Formation of polymeric microspheres using electron beam radiation
复制标题
使用电子束辐射形成聚合物微球
DOI：
10.1002/app.1991.070430603
复制
发表时间：
1991
期刊：
影响因子：
--
通讯作者：
G. Wilkes
中科院分区：
文献类型：
--
作者：
D. Mcherron;G. Wilkes
聚合物颗粒目前通过各种不同的技术生产。这种新的方法说明了交联聚合物微球的形成，通过将三丙烯酸丙氧基丙烷（辐射敏感单体）到polyaphron系统，并将其暴露于电子束辐射。多泡沫体基本上是包封在分散在水性基质中的非常薄的水性膜中的液滴的集合。该薄膜为系统提供了极高的稳定性，从而允许极高的分散相浓度。多泡沫体的形成需要在分散（单体）和连续（水）相中存在表面活性剂。研究了单体相浓度、单体相和水相表面活性剂浓度、水相表面活性剂类型和制备温度的影响，以了解促进形成具有窄尺寸分布的聚合物微球的条件。形成直径为2至40微米的聚合物微球，单体浓度高达67体积%，而不发生任何泡沫体桥接或不需要搅拌以保持单体相分散在水性基质中。此外，通过在分散相中掺入可聚合的氟化丙烯酸酯来证明降低微球的润湿性的能力。
Polymeric particulates are currently being produced by a variety of different techniques. This new approach illustrates the formation of cross-linked polymeric microspheres by incorporating trimethylolpropane propoxylate triacrylate (a radiation-sensitive monomer) into a polyaphron system and exposing it to electron beam radiation. Polyaphrons are essentially a collection of droplets encapsulated in a very thin aqueous film dispersed in a aqueous matrix. This film gives extreme stability to the system, which allows for extremely high dispersed-phase concentrations. The formation of polyaphrons requires the presence of a surfactant in both the dispersed (monomer) and continuous (aqueous) phases. The effects of monomer-phase concentration, monomer- and acqueous-phase surfactant concentration, aqueous-phase surfactant type, and preparation temperature were studied to gain an understanding of the conditions that promote the formation of polymeric microspheres with a narrow size distribution. Polymeric microspheres ranging from 2 to 40 microns in diameter were formed with monomer concentrations as high as 67 vol % without any aphron bridging occurring or need for agitation to keep the monomer-phase dispersed in the aqueous matrix. In addition, the ability to reduce the wettability of the microspheres is demonstrated through incorporation of a polymerizable fluorinated acrylate in the dispersed phase.