Titanium Dioxide Particle-induced Alkaline Degradation of Poly(ethylene Terephthalate): Application to Medical Textiles

Titanium dioxide induced degradation of bright high-tenacity poly(ethylene terephthalate) (PET:2GT) used in medical applications was investigated under both relaxed and stressed conditions. It was found that successive layers of the polymers were removed by hydrolysis as weight loss (%) was linear with the treatment time. However, owing to the presence of titanium dioxide, tenacity loss occurred and, therefore, at a given time of hydrolysis treatment, the breaking load loss (%) was greater than the weight loss (%). Scanning electron microscopy of the hydrolyzed PET showed that surface pitting occurred due to the presence of titanium dioxide. Larger pits formed on the surface of the stressed fibers than on the relaxed fibers. The findings suggest that the failure of numerous PET (Dacron) grafts, which have been responsible for many deaths, is due to the penetration of hydroxyl ions through the surface defects caused by titanium dioxide.