Kinetics and Mechanism of Stable Free Radical Miniemulsion Polymerization (SFRMP) and Application to the Preparation of Nanostructured Latex Particles

稳定自由基细乳液聚合（SFRMP）的动力学和机理及其在纳米结构乳胶颗粒制备中的应用

• 批准号: 9980208
• 负责人: Mohamed El-Aasser
• 金额: $ 25万
• 依托单位: Lehigh University
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-10-01 至 2003-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9980208&HistoricalAwards=false
• 关键词: Kinetics; Mechanism; Stable; Free; Radical

Most polymeric materials with special properties have narrow molecular weight distributions (MWDs). In this project the PIs will use a novel free radical initiator system with nitroxide stable radicals that will promote the synthesis of polymers with narrow MWDs. Initial attempts to use this initiator system in emulsion polymerizations were unsuccessful, and problems were traced to large monomer droplets. To overcome these problems, a miniemulsion polymerization technique was developed. Monomer is first dispersed in the form of submicron droplets where nucleation and polymerization occur. Polystyrene latexes with relatively high solids content and with particle sizes of 100 nm were successfully prepared, and narrow MWDs were obtained. An understanding of the kinetics and mechanism of this unique emulsion polymerization process is one of the primary goals of this project. New avenues for the synthesis of latex particles with a variety of covalently bonded functional groups (e. g., carboxyl, amino, epoxy) at the particle surface will be explored. The PIs will also take advantage of the "living" character of polymer chains in an investigation of the preparation of multi-layered colloidal particles with desired surface structures/properties by sequential monomer addition steps. The properties of these materials will be measured and are expected to differ substantially from those being made by conventional polymerization processes.

大多数具有特殊性能的聚合物材料具有窄的分子量分布（MWD）。 在这个项目中，PI将使用一种新的自由基引发剂系统，具有氮氧稳定的自由基，这将促进窄分子量分布聚合物的合成。 在乳液聚合中使用该引发剂体系的最初尝试是不成功的，并且问题被追溯到大单体液滴。 为了克服这些问题，开发了细乳液聚合技术。 首先将聚乙二醇以亚微米液滴的形式分散，在此发生成核和聚合。 成功地制备了具有相对高的固含量和粒径为100 nm的聚苯乙烯乳液，并获得了窄的分子量分布。 了解这种独特的乳液聚合过程的动力学和机理是本项目的主要目标之一。 合成具有各种共价键合官能团的胶乳颗粒的新途径（例如，例如，在一个实施例中，羧基、氨基、环氧基）。 PI还将利用聚合物链的“活性”特性，通过连续的单体加成步骤来研究具有所需表面结构/性质的多层胶体颗粒的制备。 这些材料的性能将被测量，并预计将大大不同于那些正在通过传统的聚合工艺。