Angular dependent ESCA and infrared studies of segmented polyurethanes.

Area of Science:

• Materials Science
• Polymer Chemistry
• Surface Science

Background:

• Biomedical implants rely on complex polymer mixtures with specific surface properties.
• Understanding surface composition and bonding is critical for implant performance and biocompatibility.

Purpose of the Study:

• To investigate the surface bonding and composition of biomedical polymers using a combination of analytical techniques.
• To characterize commercially available polymers (Biomer, Avcothane) and model systems (polydimethylsiloxane, Avcomat).

Main Methods:

• Utilized vibrational spectroscopy (Attenuated Total Reflectance - ATR, Photoacoustic - PA) for bulk and surface analysis.
• Employed angular-dependent X-ray Photoelectron Spectroscopy (XPS or ESCA) for detailed surface composition.
• Compared surface sensitivity and depth profiling capabilities of different spectroscopic methods.

Main Results:

• Identified impurities segregated in the near-surface region, not detected by surface infrared.
• Determined the depth of polydimethylsiloxane (DMS) block segregation in Avcothane.
• Confirmed the presence of DMS within the top 20 Angstroms of Biomer surfaces.

Conclusions:

• A multi-technique approach is essential for comprehensive understanding of complex polymer surfaces.
• Sample preparation and morphology control are critical factors in surface analysis.
• The study provides insights into the surface characteristics of biomedical polymers relevant to implant applications.