GOALI: Understanding the Role of Interfacial Structure in Controlling Oil-Resistant Properties of Elastomeric Rubbers

University Of Akron, Akron OH

Investigators

Abstract

Dhinojwala, Ali - University of Akron Mohsen Yeganeh and Dennis Peiffer - ExxonMobil Research and Engineering "GOALI: Understanding the Role of Interfacial Structure in Controlling Oil-Resistant Properties of Elastomeric Rubbers" The objective of this research is to study the surface interaction of two important commercial elastomers, EXXPRO and nitrile rubbers, with oil and water. EXXPRO and nitrile rubbers are based on brominated methylstyrene and polyacrylonitrile (PAN), respectively. In the U.S. alone, the production of copolymers based on PAN and EXXPRO is 1 billion lbs./year. The oil-resistance and good weatherability properties of these substances are inherently dependent on understanding the interaction of these polymers with hydrophobic and hydrophilic liquids (oil and water). The PIs propose to study the molecular structure at polymer/liquid interface using a surface-sensitive infrared-visible sum frequency generation spectroscopy (SFG). The content of PAN in nitrile rubber and brominated methylstyrene in EXXPRO will be varied systematically, and the influence of these polar substitutions on the surface structure will be studied at air, water, and n-alkane interfaces. Selectively deuterated polymers and liquids will be used to independently study the orientation of both the polymer and water (or alkanes) groups at the interface. This information will allow development of a fundamental understanding of the relationship between the structures at the interface and their oil-resistant and weatheribility properties. The research focuses on applying this new surface characterization technique on industrially important copolymers that contain both hydrophobic and hydrophilic groups. Hydrophilic and hydrophobic segments are also the main ingredients of copolymers for biomedical applications, coatings and surface-active additives. This study will help in understanding these systems as well. Broader Impact: The surface interaction of polymers with liquids is important in many industrial and biomedical applications. The interaction of acrylonitrile in acrylic fibers or gasoline pipelines with water or oil is important in understanding the mechanism behind these applications. This work will provide a direct measurement of the structure of both the polymer molecules and hydrophobic or hydrophilic liquids at the polymer/liquid interfaces. This information will be important to ExxonMobil and other industries involved in designing polymers that are often exposed to water or other fluids. The long- term goal of this research is to aid scientists in designing engineered copolymers using mettalocene chemistry to produce better oil and water resistant properties. This study will also provide important insight into the development of biocompatible (bio-invisible) polymers for biomaterial applications. The project will also provide valuable training to the post-doctoral and graduate students because of their collaboration in an industrial laboratory.