Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Effect of silica nanoparticles on morphology of segmented polyurethanes

Journal Article · · Polymer
OSTI ID:1008742
Two series of segmented polyurethanes having soft segment concentration of 50 and 70 wt%, and different concentrations of nanometer-diameter silica were prepared and tested. Atomic force microscopy revealed a strong effect of nanoparticles on the large-scale spherulitic morphology of the hard domains. Addition of silica suppresses fibril formation in spherulites. Filler particles were evenly distributed in the hard and soft phase. Nano-silica affected the melting point of the hard phase only at loadings >30 wt% silica. A single melting peak was observed at higher filler loadings. There is no clear effect of the filler on the glass transition of soft segments. Wide-angle X-ray diffraction showed decreasing crystallinity of the hard domains with increasing filler concentration in samples with 70 wt% soft segment. Ultra small-angle X-ray scattering confirms the existence of nanometer phase-separated domains in the unfilled sample. These domains are disrupted in the presence of nano-silica. The picture that emerges is that nano-silica suppresses short-scale phase separation of the hard and soft segments. Undoubtedly, the formation of fibrils on larger scales is related to short-scale segment segregation, so when the latter is suppressed by the presence of silica, fibril growth is also impeded.
Research Organization:
Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
Sponsoring Organization:
USDOE
OSTI ID:
1008742
Journal Information:
Polymer, Journal Name: Polymer Journal Issue: (12) ; 2004 Vol. 45; ISSN 0032-3861; ISSN POLMAG
Country of Publication:
United States
Language:
ENGLISH

Similar Records

Phase structure in segmented polyurethanes having fatty acid-based soft segments
Journal Article · Mon Dec 31 23:00:00 EST 2012 · Polymer · OSTI ID:1362029

Thermoplastic polyurethanes with controlled morphology based on methylenediphenyldiisocyanate/isosorbide/butanediol hard segments: Thermoplastic polyurethanes with controlled morphology
Journal Article · Tue Jun 30 00:00:00 EDT 2015 · Polymer International · OSTI ID:1392417

Thermoplastic Polyurethanes with Isosorbide Chain Extender
Journal Article · Mon Dec 14 23:00:00 EST 2015 · Journal of Applied Polymer Science · OSTI ID:1245017