The utilization of polyurethanes derived from castor oil in the prosthetics device: preliminary study

Abstract

With a view to using it as lining material for below knee prosthesis, this research developed and tested the mechanical resistance of a new polyurethane derived from castor oil, using of tensile strength measurement, and compared to with two other materials. The silicone elastomer and synthetic rubber foam, both of current use for the same purpose. The castor oil polyurethane and the silicone elastomer were tested either in a care, summing up five types of materials investigated. The parameters taken into consideration for analysis were the maximal load supported, the maximal at rupture, the elongation at rupture and modulus of elasticity for each material. The results showed the silicone elastomer with and without the mesh core was the most resistant material and that the resistance of the plain castor oil polyurethane is close to that of rubber foam. When combined with the mesh core, the resistance of the polyurethane became similar to that of the plain silicone elastomer. However, the polyurethane was the materials more flexible than silicone elastomer and than rubber foam. It was concluded that, despite weaker, the resistance of castor oil polyurethane can be increased by the combination with the mesh core, still preserving its greater flexibility and shock absorbing and load distribution capacity, as compared to the silicone elastomer. In this form it is, therefore an adequate material to make soft sockets for below knee prostheses.