The effect of strain state on the biostability of a poly(etherurethane urea) elastomer

• Published in: Journal of biomedical materials research Vol. 35; no. 3; pp. 319 - 329
• Main Authors: Schubert, Mark A., Wiggins, Michael J., Anderson, James M., Hiltner, Anne
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 05-06-1997; John Wiley & Sons
• Subjects: Biocompatible Materials - chemistry; Biological and medical sciences; Cobalt; Drug Stability; Hydrogen Peroxide; Kinetics; Medical sciences; Microscopy, Electron, Scanning; Polyurethanes - chemistry; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Rubber - chemistry; Spectroscopy, Fourier Transform Infrared; Stress, Mechanical; Technology. Biomaterials. Equipments. Material. Instrumentation; Time Factors; Scanning electron microscopy; Oxidative stress; Fourier transformation; Stability; Elastomer; Mechanical properties; In vitro; Degradation; Deformation measurement; Infrared spectrometry; Stress distribution; Biomaterial; Stress relaxation test; Etherurethane polymer; Physicochemical properties
• ISSN: 0021-9304; 1097-4636
• DOI: 10.1002/(SICI)1097-4636(19970605)35:3<319::AID-JBM6>3.0.CO;2-K

The effect of deformation state on degradation of a PEUU without added stabilizers was examined in an oxidative environment that simulates the in vivo biodegradation of the polymer. Polymer tubes were stressed uniaxially and biaxially over glass mandrels and treated in 20% hydrogen peroxide/0.1M cobalt chloride solution for 12 days at 37°C. The amount of degradation was determined from the ATR‐FTIR peak height of the amorphous aliphatic ether absorbance at 1110 cm−1. If a uniaxial stress was applied, degradation was inhibited and the amount of surface ether remaining after treatment increased linearly with strain. If the stress was biaxial, the amount of degradation was not reduced unless the strain was greater than 200%. Decreased degradation correlated with the amount of soft‐segment orientation. The decreased degradation rate was attributed to compaction of the polyether phase by orientatin, which resulted in lower permeability to oxidative agents, particularly oxygen. Macroscopic damage was confined to a thin peeling surface layer if the stress was uniaxial. In comparison, biaxially stressed PEUU ruptured. © 1997 John Wiley & Sons, Inc.