Characterization and Analysis of Hydroxyl-terminated Polybutadiene
Host
Department of Chemistry
Description
Abstract
Hydroxyl-terminated polybutadiene (HTPB) resin is used in the production of polyurethane rubber with applications ranging from commercial sealants to rubber binder. In recent years, HTPB production has inconsistently produced binder with both acceptable and unacceptable mechanical properties. Variability in HTPB lot production is under investigation as current methods of lot acceptance have not been able to properly identify unacceptable material. Thorough characterization of the HTPB polymer by various analytical chemistry techniques has provided insight into structure-property relationships, specifically identifying markers in the polymer structure that inhibit desirable mechanical properties upon cure. Several analytical techniques were used to characterize the variable backbone and end-group structure of HTPB: Fourier Transform Infrared (FTIR) spectroscopy, confocal Raman spectroscopy, Gel Permeation Chromatography – Multiangle Light Scattering (GPC-MALS), Matrix-assisted laser desorption/ionization – Time of Flight (MALDI-TOF) and Nuclear Magnetic Resonance (NMR) spectroscopy. FTIR is the analytical technique of choice due to its wide availability. Detailed interpretation of the FTIR spectra shows an increased aldehyde peak at 1700 cm-1 that correlates with poor mechanical behavior. However, NMR provides the most comprehensive characterization of the HTPB polymer with information regarding molecular weight, the ratio of trans-, cis- and vinyl- end groups, OH functionality, and determination of epoxide and aldehyde content.
About the Speaker
Aura Labatete Goeppinger is an analytical chemist in the Materials Science Department, Space Materials Laboratory of The Aerospace Corporation, a Federally Funded Research and Development Center in El Segundo, California. She is currently a graduate student at the Illinois Institute of Technology and will complete her M.S. in Analytical Chemistry in the Summer of 2019. Goeppinger received her B.S. in Chemistry from The Catholic University of America in Washington, D.C. As an undergraduate, she participated in the Research Experience for Undergraduates program at Georgetown University in Washington, D.C. synthesizing and characterizing copper-halide-ligand compounds. She also spent a summer with the NASA Academy program at Marshall Space Flight Center in Huntsville, AL investigating methods of maintaining air quality on the International Space Station. Goeppinger later attended graduate courses and performed research on uranium complexes at the University of California Los Angeles. Her current research at Aerospace involves characterization of materials used in ground systems, launch vehicles, and spaceflight hardware. These investigations often consist of failure analyses requiring customized analytical method development utilizing a wide range of techniques including GC-MS, HPLC, FTIR and SEM-EDS.