Mechanical properties of polyurethane foam for potential application in the prevention and treatment of pressure ulcers

Abstract

The viscoelastic property is a crucial parameter for evaluating the feasibility of the foam to be used as pressure relief. This work aims to perform experimental measurements to determine the dependence of the viscous behavior of polyurethane foam on density and energy dissipation. Experimental measurements were realized for three types of polyurethane foams with different densities soft, medium and hard. The compression tests at room temperature characterized the mechanical properties of these samples. Furthermore, the structures of the samples were characterized using scanning electron microscopy (SEM). A proportional relationship was observed between the density of polyurethane (PU) foam and the tolerated strength at 90% compression. This material has an excellent remanence (persistence) which showed by the creep experiments at constant stress (2, 5, 10 N) for 6 h. Young Modulus, relaxation time and dissipation coefficient (DE) were also calculated from the stress-strain curve. Moreover, softening behavior, which is responsible for pressure relief, was measured by a cyclic compression test. This paper assesses the capacity of polyurethane to effectively maintain interfacial pressure below the critical threshold of 32 mm of mercury, which represents a significant risk level for the development of pressure sores.