Dynamic opto-rheological study of estane copolymers using step-scan FTIR spectroscopy
- Duke Univ., Durham, NC (United States). Dept. of Chemistry
- Los Alamos National Lab., NM (United States)
Polyurethane copolymers generally consist of linear segments of polyurethane and polyester (or polyether). At room temperature, these polymers undergo a micro-phase separation, in which the polyurethane segments form hard domains while the polyester segments form relatively soft domains that act as the crosslinks between the hard cores. A wide variety of techniques has been utilized to characterize the microscopic (molecular) structure of polymeric materials. Recently, the dynamic infrared opto-rheological method has been developed, which involves the combination of dynamic mechanical analysis (DMA) and time-resolved infrared (IR) spectroscopy to study the real time IR spectral changes in polymer films under sinusoidal (or impulse) tensile stress of small amplitude. Phase-locked electronics are used to record the dynamic infrared spectral change in-phase and in-quadrature with the applied mechanical field. The result provides insight on the response to the external stress on the molecular and submolecular scale. While for relatively narrow spectral ranges this experiment is efficiently carried out by use of a dispersive spectrometer, for measurements over broader spectral windows, the use of step-scan Fourier transform infrared (S{sup 2}FT-IR) has proved to be more effective. In the study reported here, dynamic opto-rheology using S{sup 2}FT-IR spectroscopy has been applied to the polyurethane/polyester copolymer Estane 5703. Dynamic in-phase and quadrature spectra in the mid-IR region at two orthogonal polarizations have been collected, and dynamic dichroic spectra calculated and interpreted.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE Assistant Secretary for Human Resources and Administration, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 661440
- Report Number(s):
- LA-UR-98-505; CONF-980314-; ON: DE98003459; TRN: AHC29814%%56
- Resource Relation:
- Conference: American Chemical Society (ACS) meeting, Dallas, TX (United States), 26 Mar - 2 Apr 1998; Other Information: PBD: [1998]
- Country of Publication:
- United States
- Language:
- English
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