Phase Separation in Polyurethanes - A Deuterium NMR Study.
Abstract
Solid state deuterium NMR spectroscopy is used to address phase separation i specifically labeled polyurethanes. The hard segment is 4,4'-diphenyl-methane diisocyanate (MDI) chain extended with 2,2,3,3,-D SUB 4 butanediol and the soft segment is polyoxypropylene end-capped with oxyethylene. The samples contain 100, 70, 60 and 50 wt% hard segment. The results show 1) that the core of the hard segment microdomains is identical to the pure hard segment material with respect to molecular motion; 2) that the amount of hard segment in the interfacial regions can be quantified; 3) that the NMR and SAXS data are in good agreement concerning the fraction of interfacial hard segment; and 4) that the interfacial hard segments undergo nearly isotropic motion on a 10,000,000/s time scale, suggesting that there are few long-lived interrurethane hydrogen bonding interactions in the interfacial area. Author keywords include: Polyurethanes; Small Angle X-ray Scattering; Microphase Separation; Deuterium NMR.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 18, 1985
- Accession Number
- ADA151515
Entities
People
- A. Galambos
- I. Gancarz
- J. J. Dumais
- L. M. Leung
- L. W. Jelinski
Organizations
- Princeton University