title: Evaluation of damage progression and mechanical behavior under compression of bone cements containing core-shell nanoparticles by using acoustic emission technique.
abstract: In this work, the effect of the incorporation of core-shell particles on the fracture mechanisms of the acrylic bone cements by using acoustic emission (AE) technique during the quasi-static compression mechanical test was investigated. Core-shell particles were composed of a poly(butyl acrylate) (PBA) rubbery core and a methyl methacrylate/styrene copolymer (P(MMA-co-St)) outer glassy shell. Nanoparticles were prepared with different core-shell ratio (20/80, 30/70, 40/60 and 50/50) and were incorporated into the solid phase of bone cement at several percentages (5, 10 and 15 wt%). It was observed that the particles exhibited a spherical morphology averaging ca. 125 nm in diameter, and the dynamic mechanical analysis (DMA) thermograms revealed the desired structuring pattern of phases associated with core-shell structures. A fracture mechanism was proposed taking into account the detected AE signals and the scanning electron microscopy (SEM) micrographs. In this regard, core-shell nanoparticles can act as both additional nucleation sites for microcracks (and crazes) and to hinder the microcrack propagation acting as a barrier to its growth; this behavior was presented by all formulations. Cement samples containing 15 wt% of core-shell nanoparticles, either 40/60 or 50/50, were fractured at 40% deformation. This fact seems related to the coalescence of microcracks after they surround the agglomerates of core-shell nanoparticles to continue growing up. This work also demonstrated the potential of the AE technique to be used as an accurate and reliable detection tool for quasi-static compression test in acrylic bone cements.
authors: Unidad de Materiales, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130., Col. Chuburná de Hidalgo, C.P. 97200 Mérida, Yucatán, Mexico.
authors: O F
authors: OF
authors: Pacheco-Salazar
authors: Tokyo Metropolitan University 1-1 Minami-Osawa, Hachioji-shi, Tokyo 192-0397, Japan.
authors: Shuichi
authors: S
authors: Wakayama
authors: Tokyo Metropolitan University 1-1 Minami-Osawa, Hachioji-shi, Tokyo 192-0397, Japan.
authors: Takenobu
authors: T
authors: Sakai
authors: Unidad de Materiales, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130., Col. Chuburná de Hidalgo, C.P. 97200 Mérida, Yucatán, Mexico.
authors: J V
authors: JV
authors: Cauich-Rodríguez
authors: Unidad de Materiales, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130., Col. Chuburná de Hidalgo, C.P. 97200 Mérida, Yucatán, Mexico.
authors: C R
authors: CR
authors: Ríos-Soberanis
authors: Unidad de Materiales, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130., Col. Chuburná de Hidalgo, C.P. 97200 Mérida, Yucatán, Mexico. Electronic address: manceruc@cicy.mx.
authors: J M
authors: JM
authors: Cervantes-Uc
mesh_terms: D000162:Acoustics; D001843:Bone Cements / Q000737:chemistry*; D019245:Compressive Strength; D008422:Materials Testing; D053758:Nanoparticles; D011108:Polymers / Q000737:chemistry
chemical_list: D001843:Bone Cements; D011108:Polymers
keywords: Acoustic emission; Acrylic bone cement; Core-shell nanoparticles