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Surface characterization of segmented siloxane–urethane block copolymers
Author(s) -
Benrashid R.,
Nelson G. L.,
Linn J. H.,
Hanley K. H.,
Wade W. R.
Publication year - 1993
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1993.070490316
Subject(s) - siloxane , thermogravimetric analysis , copolymer , materials science , polymer , differential scanning calorimetry , silicone , polymer chemistry , scanning electron microscope , fourier transform infrared spectroscopy , chemical engineering , thermal stability , composite material , physics , engineering , thermodynamics
Abstract New siloxane–urethane block copolymers were synthesized and the effect of a siloxane moiety on microphase segregation in soft/hard block copolymers was studied by several analytical methods. Scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) provided topographical and bulk composition information. Electron Spectroscopy for Chemical Analysis (ESCA) provided surface chemical information. Fourier Transform Infrared Spectroscopy (FTIR) provided chemical bond information for the near‐surface region. Thermogravimetric Analysis (TGA) provided information concerning the thermal stability of the polymers. Differential Scanning Calorimetry (DSC) provided information on the soft and hard block segments within the polymer. These studies showed that the block copolymer contained and enhanced silicone‐containing surface. For films cast on glass, less silicon was detected in the bulk (exposed by physically removing the surface material), and on the backside (glass) of the polymer film, than on the air‐exposed surface. Of particular interest is the fact that data also show that the solvents, from which the polymers were cast, have a significant influence on microphase segregation. The films cast from THF have higher silicone concentrations at the surface as compared to polymers cast from DMAC/CH 2 CL 2 or dioxane. © 1993 John Wiley & Sons, Inc.