Porous Open-Сell UHMWPE: Experimental Study of Structure and Mechanical Properties

Abstract

Ultra-high molecular weight polyethylene (UHMWPE) is a bioinert polymer that is widely used as bulk material in reconstructive surgery for structural replacements of bone and cartilage. Porous UHMWPE can be used for trabecular bone tissue replacement, and it can be used in living cell studies as bioinert 3D substrate permeable to physiological fluids. It is important to develop techniques to govern the morphology of open-cell porous UHMWPE structures (pore size, shape, and connectivity), since this allows control over proliferation and differentiation in living cell populations. We report experimental results on the mechanical behavior of porous open-cell UHMWPE obtained through sacrificial removal (desalination) of hot-molded UHMWPE-NaCl powder mixtures with pore sizes in the range 75 µm to 500 µm. The structures were characterized using SEM and mechanically tested under static compression and dynamic mechanical analysis (DMA), bending, and tensile tests. Apparent elastic modulus and complex modulus were in the range of 1.2 to 2.5 MPa showing a weak dependence on cell size. Densification under compression caused the apparent elastic modulus to increase to 130 MPa.

Multi-Scale Digital Image Correlation Analysis of In Situ Deformation of Open-Cell UHMWPE Foam

“…The structure and morphological characteristics of used powders are illustrated in Figure 1. The porous samples preparation method included the following technological procedures as mixing, hot pressing, and salt dissolution step according to the regime used in our previous paper [12].…”

“…Recently we placed our attention [12] on the static and dynamic mechanical testing in compression, bending, and tension of UHMWPE open-cell porous structures obtained via sacrificial desalination of hot compression-moulded UHMWPE-NaCl powder mixtures. it was shown with the help of optical and electron microscopy that significant inhomogeneity of strain distributed over the stochastic cellular structure seems to govern the overall response.…”

Design and Characterization of the Surface Porous UHMWPE Composite Reinforced by Graphene Oxide

“…Articular cartilage with porous structure has the advantage to provide human joints with excellent bearing capacity, bio-friction, and wear resistance performance [7]. Porous UHMWPE simulating as closely as possible the porous articular cartilage is a promising composite polymer used for various implant materials [8,9]. The various type and distribution of the filler materials are associated with the versatility of composite polymers.…”

Fabrication of Self-Lubricating Porous UHMWPE with Excellent Mechanical Properties and Friction Performance via Rotary Sintering

“…However, the high price of PI and PEEK limits their large-scale production/application [16][17][18]. Compared to other polymer porous materials, UHMWPE porous material products have the advantages of light weight, high specific strength, and good permeability [19][20][21]. Nowadays, research on the UHMWPE porous self-lubricating material is rare.…”