Amalvy J I, Unali G F, Li Y, Granger-Bevan S, Armes S P, Binks B P, Rodrigues J A, Whitby C P
Department of Chemistry, University of Sussex, Falmer, Brighton, BN1 9QJ, UK.
Langmuir. 2004 May 25;20(11):4345-54. doi: 10.1021/la035921c.
2-(Dimethylamino)ethyl methacrylate (DMA) was block copolymerized with methyl methacrylate (MMA) using group transfer polymerization to give four AB diblock, ABA triblock, and BAB triblock copolymers of low polydispersity (Mw/Mn < 1.20). In addition, a near-monodisperse styrene-functionalized DMA-based macromonomer was synthesized via oxyanionic polymerization using a potassium 4-vinylbenzyl alcoholate initiator. These five well-defined, tertiary amine methacrylate-based copolymers were evaluated as steric stabilizers for the synthesis of polystyrene latexes via emulsion and dispersion polymerization. The most efficient steric stabilizers proved to be the DMA-MMA diblock copolymer and the DMA-based macromonomer. The polystyrene latexes were characterized in terms of their particle size and morphology, stabilizer content, surface charge, and surface activity using dynamic light scattering, scanning electron microscopy, 1H NMR spectroscopy, aqueous electrophoresis measurements, and surface tensiometry, respectively. The pH-dependent surface activity exhibited by selected latexes suggests potential applications as stimulus-responsive particulate emulsifiers for oil-in-water emulsions.
采用基团转移聚合方法，使甲基丙烯酸2-(二甲氨基)乙酯（DMA）与甲基丙烯酸甲酯（MMA）进行嵌段共聚，得到了四种低多分散性（Mw/Mn < 1.20）的AB二嵌段、ABA三嵌段和BAB三嵌段共聚物。此外，使用4-乙烯基苄醇钾引发剂通过氧阴离子聚合反应合成了一种近单分散的、基于DMA的苯乙烯官能化大分子单体。通过乳液聚合和分散聚合反应，对这五种结构明确的、基于甲基丙烯酸叔胺酯的共聚物作为聚苯乙烯胶乳合成的空间稳定剂进行了评估。结果表明，最有效的空间稳定剂是DMA-MMA二嵌段共聚物和基于DMA的大分子单体。分别使用动态光散射、扫描电子显微镜、1H核磁共振光谱、水性电泳测量和表面张力测定法，对聚苯乙烯胶乳的粒径和形态、稳定剂含量、表面电荷和表面活性进行了表征。所选胶乳表现出的pH依赖性表面活性表明，它们作为水包油乳液的刺激响应型颗粒乳化剂具有潜在的应用价值。
