In vitro oxidation of high polydimethylsiloxane content biomedical polyurethanes: Correlation with the microstructure
Rebeca Hernandez,
Jadwiga Weksler,
Ajay Padsalgikar,
James Runt,
Corresponding Author
Rebeca Hernandez
Department of Materials Science and Engineering, Pennsylvania State University, Pennsylvania
Department of Materials Science and Engineering, Pennsylvania State University, PennsylvaniaSearch for more papers by this authorJadwiga Weksler
Aortech Biomaterials, Dalmore Drive, Caribbean Park, Scoresby, Victoria 3179, Australia
Search for more papers by this authorAjay Padsalgikar
Aortech Biomaterials, Dalmore Drive, Caribbean Park, Scoresby, Victoria 3179, Australia
Search for more papers by this authorJames Runt
Department of Materials Science and Engineering, Pennsylvania State University, Pennsylvania
Search for more papers by this authorRebeca Hernandez,
Jadwiga Weksler,
Ajay Padsalgikar,
James Runt,
Corresponding Author
Rebeca Hernandez
Department of Materials Science and Engineering, Pennsylvania State University, Pennsylvania
Department of Materials Science and Engineering, Pennsylvania State University, PennsylvaniaSearch for more papers by this authorJadwiga Weksler
Aortech Biomaterials, Dalmore Drive, Caribbean Park, Scoresby, Victoria 3179, Australia
Search for more papers by this authorAjay Padsalgikar
Aortech Biomaterials, Dalmore Drive, Caribbean Park, Scoresby, Victoria 3179, Australia
Search for more papers by this authorJames Runt
Department of Materials Science and Engineering, Pennsylvania State University, Pennsylvania
Search for more papers by this authorAbstract
The resistance to in vitro metal ion oxidation of a polydimethylsiloxane (PDMS)-containing thermoplastic polyurethane elastomer (Elast-Eon™) is compared with that of a polyurethane consisting of the same hard segment chemistry and content, but with aliphatic polycarbonate soft segments (PCU). Scanning electron microscopy and attenuated total reflectance Fourier transform infrared spectroscopy were used to assess changes in surface morphology and chemistry. The extent of bulk degradation was assessed indirectly by dynamic mechanical analysis and small-angle X-ray scattering experiments. The findings indicate that Elast-Eon™ is more resistant to oxidation than the PCU, because of the presence of the PDMS soft segments as well as its phase separated microstructure. The PCU exhibits a rather high degree of intermixing between hard and soft segments, rendering the hard segments dissolved or trapped in the soft phase more susceptible to oxidative conditions. By contrast, we propose that the existence of a completely phase separated PDMS soft phase in Elast-Eon™ protects the remainder of the segments from oxidation. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
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