• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Stimuli-responsive polyampholytes based on acrylamide and amino acid derived N-substituted acryoyl monomers: Synthesis, characterization, and aqueous solution behavior ofpH- and salt-responsive model systems.
【24h】

Stimuli-responsive polyampholytes based on acrylamide and amino acid derived N-substituted acryoyl monomers: Synthesis, characterization, and aqueous solution behavior ofpH- and salt-responsive model systems.

机译：基于丙烯酰胺和氨基酸衍生的N取代的丙烯酰基单体的刺激响应性两性电解质：pH和盐响应模型系统的合成，表征和水溶液行为。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The fundamental structure-property-performance relationships of stimuli-responsive polyampholytes synthesized from acrylamido monomers were studied utilizing well-defined model systems. In order to elucidate significant comparisons between polyampholytes of varying compositions, it was necessary to prepare model terpolymers with random charge distributions, homogeneous compositions, and well-defined molecular weights (MW) and molecular weight distributions (MWDs). Thus, low-charge-density amphoteric copolymers and terpolymers composed of acrylamide (AM), (3-acrylamidopropyl)trimethyl ammonium chloride (APTAC), and the amino acid derived monomers (e.g. N-acryloyl valine (AVA), N-acryloyl alanine (AAL), and N-acryloyl aspartate (AAS)) were prepared via free-radical polymerization in aqueous media to yield terpolymers with random charge distributions and homogeneous compositions. Sodium formate (NaOOCH) was employed as a chain transfer agent during the polymerization to suppress gel effects and broadening of the MWD. Terpolymer compositions were determined by 13C and 1H NMR spectroscopy. Terpolymer MWs and polydispersity indices (PDIs) were obtained via size exclusion chromatography/multi-angle laser light scattering (SEC-MALLS) while hydrodynamic diameters were obtained via dynamic light scattering. Intrinsic viscosities determined by SEC-MALLS utilizing the Flory-Fox equation were found to agree with intrinsic viscosities measured via dilute solution viscometry. The data from SEC-MALLS experiments allowed for the comparison of radius of gyration-MW (Rg-M) relationships and the Mark-Houwink-Sakurada intrinsic viscosity-MW ([eta]-M) relationships for terpolymers and provided information regarding the dependence of macromolecular conformation and solvation on terpolymer composition. The Rg-M and [eta]-M relationships indicated little or no excluded volume effects under SEC conditions (expected near theta conditions of the measurements).; The pH- and salt-responsive dilute solution viscosity behavior of the low-chargedensity amphoteric copolymers and terpolymers has been examined to assess the effects of polymer structure and composition on solution properties. The low-charge-density terpolymers display excellent solubility in deionized (DI) water with no phase separation. The charge-balanced terpolymers exhibit antipolyelectrolyte behavior at pH values ≥ (6.5 +/- 0.2). (Abstract shortened by UMI.)
机译：利用明确定义的模型系统研究了由丙烯酰胺基单体合成的刺激反应性两性电解质的基本结构-性能-性能关系。为了阐明不同组成的多两性电解质之间的显着比较，有必要制备具有随机电荷分布，均一组成以及明确定义的分子量（MW）和分子量分布（MWD）的模型三元共聚物。因此，由丙烯酰胺（AM），（3-丙烯酰胺基丙基）三甲基氯化铵（APTAC）和氨基酸衍生的单体（例如N-丙烯酰基缬氨酸（AVA），N-丙烯酰基丙氨酸）组成的低电荷密度两性共聚物和三元共聚物（AAL）和N-丙烯酰基天冬氨酸盐（AAS）是通过在水性介质中进行自由基聚合制备的，得到具有随机电荷分布和均一组成的三元共聚物。在聚合过程中，将甲酸钠（NaOOCH）用作链转移剂，以抑制凝胶效应和MWD增宽。三元共聚物组成通过13 C和1 H NMR光谱测定。通过尺寸排阻色谱/多角度激光散射（SEC-MALLS）获得三元共聚物的分子量和多分散指数（PDI），而通过动态光散射获得流体动力学直径。发现通过SEC-MALLS利用Flory-Fox方程确定的本征粘度与通过稀溶液粘度法测得的本征粘度一致。来自SEC-MALLS实验的数据允许比较三元共聚物的回转半径-MW（Rg-M）关系和Mark-Houwink-Sakurada特性粘度-MW（η-M）关系，并提供有关依赖性的信息。构象和溶剂化对三元共聚物组成的影响Rg-M和η-M关系表明在SEC条件下（预期在测量的θ条件附近）很少或没有排除的体积效应。已检查了低电荷密度两性共聚物和三元共聚物的pH和盐响应性稀溶液粘度行为，以评估聚合物结构和组成对溶液性能的影响。低电荷密度三元共聚物在去离子（DI）水中显示出极好的溶解性，没有相分离。电荷平衡的三元共聚物在pH值≥（6.5 +/- 0.2）时表现出抗聚电解质行为。 （摘要由UMI缩短。）

著录项

  • 作者

    Ezell, Ryan Gillis.;

  • 作者单位

    The University of Southern Mississippi.;

  • 授予单位 The University of Southern Mississippi.;
  • 学科 Chemistry Polymer.
  • 学位 Ph.D.
  • 年度 2006
  • 页码 132 p.
  • 总页数 132
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 高分子化学（高聚物）;
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号