The Fundamentals of Admicellar Polymerization

胶束聚合的基础知识

• 批准号: 9521985
• 负责人: Brian Grady
• 金额: $ 27.5万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-04-15 至 2000-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9521985&HistoricalAwards=false
• 关键词: Fundamentals; Admicellar; Polymerization

Abstract - Grady - 9521985 A process called admicellar polymerization has been developed which can be used to form a very thin layer of polymer on a surface via a surfactant template. In this process a polymer is formed in the hydrophobic region of a surfactant bilayer absorbed on the surface. Through a cooperative research effort between PPG Industries and the Institute of Applied Surfactant Research at the University of Oklahoma, it has been shown that admicellar polymerized styrene-diene copolymers formed on a commercial precipitated silica significantly improve the properties of the silica as a filler for a rubber which serves as a model for automobile tires. Silica-filled tire treads may have advantages over normal carbon black filled tire treads, such as lower heat buildup and improved resistance to chipping/chunking. Silica-filled treads can also have a lower rolling resistance leading to better fuel economy and reduced emissions of greenhouse gases, while also having improved traction on wet pavement. These tires have not been popular because use of a costly organosilane coupling agent and increased mixing times are required. Admicellar polymerization might offer a mechanism for producing a silica-filled tread with these same performance advantages, yet a coupling agent is not required. The objectives of this research are to: (1) develop a kinetic expression for admicellar polymerization, (2) understand the effect of polymer composition on the improvement in filler properties, and (3) determine the relationship between silica pore structures and admicellar polymerization. To address the first objective, model surfaces will be used to isolate the kinetic problem from the pore diffusion problem. Since admicellar polymerization superficially resembles emulsion polymerization, Smith-Ewart kinetics will provide the theoretical starting point. The second objective is motivated by the fact that a silica modified with a styrene-diene copolymer has better filler properties than a silica modified with either homopolymer. The third part of the project will explore pore structure effects using controlled pore-size precipitated silicas in combination with scattering and liquid adsorption measurements to quantify changes in pore size.

摘要/ Abstract摘要：一种叫做胶束聚合的方法被开发出来，它可以通过表面活性剂模板在表面上形成一层很薄的聚合物。在该工艺中，在表面吸收的表面活性剂双分子层的疏水区域形成聚合物。通过PPG工业公司和俄克拉荷马大学应用表面活性剂研究所之间的合作研究，已经表明，在商业沉淀二氧化硅上形成的胶团聚合苯乙烯-二烯共聚物显著改善了二氧化硅作为汽车轮胎模型橡胶填料的性能。二氧化硅填充的轮胎胎面可能比普通炭黑填充的轮胎胎面有优势，例如更低的热量积累和更好的抗碎裂/块化。二氧化硅填充的胎面还可以具有更低的滚动阻力，从而提高燃油经济性，减少温室气体排放，同时还可以改善潮湿路面的牵引力。这些轮胎不受欢迎，因为使用昂贵的有机硅烷偶联剂和增加的混合时间是必需的。胶束聚合可以提供一种机制来生产具有相同性能优势的二氧化硅填充胎面，但不需要偶联剂。本研究的目的是：(1)建立胶束聚合的动力学表达式；(2)了解聚合物组成对填料性能改善的影响；(3)确定硅孔结构与胶束聚合之间的关系。为了解决第一个目标，将使用模型表面将动力学问题与孔隙扩散问题分离开来。由于胶束聚合表面上类似于乳液聚合，史密斯-埃沃特动力学将提供理论起点。第二个目标的动机是用苯乙烯-二烯共聚物改性的二氧化硅比用任何一种均聚物改性的二氧化硅具有更好的填料性能。该项目的第三部分将探索孔隙结构的影响，利用可控孔径的沉淀二氧化硅，结合散射和液体吸附测量来量化孔径的变化。