Supramolecular Elastomers Based on Oligo(β-Alanine) Crosslinking Platform
Views：949 Date：2014/3/10
Ph. D. Li Jia The University of Akron,USA
Title:Supramolecular Elastomers Based on Oligo(β-Alanine) Crosslinking Platform
Abstract:
Poly(b-alanine), or Nylon 3, is a highly crystalline polymer that decomposes before it melts and only dissolves in acids. In the crystalline state, neighboring poly(b-alanine) chains associate via hydrogen bonds to result in supramolecular sheets reminiscent of the b-structure of natural peptides (Scheme 1).
Scheme 1. Unit cell of the poly(b-alanine) crystal. The molecular structure and secondary structure of poly(b-alanine) are shown to the right.
The sheets stack over each other to form the 3rd dimension of the crystal structure. Very short oligo(b-alanine)s retain the strong propensity of forming the b-sheet-type supramolecular structure and can melt below the decomposition temperature. The high polarity of the molecular structure and the high propensity of self-association suggest that oligo(b-alanine)s would readily phase-separate from hydrocarbon polymers and physically crosslink and reinforce the hydrocarbon polymers.
My group started to explore the supramolecular oligo(b-alanine)s platform a few years ago, particularly focusing on its application in elastomeric materials. We have cumulated knowledge concerning the structures of the thermoplastic elastomers at the molecular, supramolecular, and morphological levels. The mechanical and dynamic mechanical properties of the materials have also been studied. Understanding the structure-property relationship of this class of novel elastomer is an important emphasis throughout the study. Discussion on the above aspects of the supramolecular oligo(b-alanine)-based elastomers will be the subject of this presentation.
________________________________
Biography:
EDUCATION •B. Sc., 1991, Lanzhou University, Lanzhou, Gansu, P. R. China. •Ph. D., 1996, advised by Professor Tobin J. Marks, Northwestern University, Evanston, IL 60208.
PROFESSIONAL EMPLOYMENTS •1996?1998, Postdoctoral Fellow with Professor Richard A. Andersen, University of California, Lawrence Berkeley Laboratory, Berkeley, CA 94720. •1998?2005, Assistant Professor, Department of Chemistry, Lehigh University, Bethlehem, PA 18015. •2005?2007, Senior Scientist and Group Leader, Rohm and Haas Electronic Materials, Marlborough, MA 01752. •2007?2011, Assistant Professor, 2011?present, Associate Professor, Department of Polymer Science, The University of Akron, Akron, OH 44325.
AWARDS •NSF CAREER Award (2002) •DuPont Young Investigator Award (2001) •Lindback Minority Junior Faculty Award (2000)
CURRENT RESEARCH INTERESTS Supramolecular elastomers and metal-catalyzed polymerizations.
OTHRT RESEARCH SPECIALTIES Photolithography materials, colloidal self-assembly, and soft lithography.
Ph. D. Li Jia