title: Assessment of mechanical behavior of PLA composites reinforced with Mg micro-particles through depth-sensing indentations analysis.
abstract: This work deals with the mechanical characterization by depth-sensing indentation (DSI) of PLLA and PLDA composites reinforced with micro-particles of Mg (up to 15wt%), which is a challenging task since the indented volume must provide information of the bulk composite, i.e. contain enough reinforcement particles. The composites were fabricated by combining hot extrusion and compression moulding. Physico-chemical characterization by TGA and DSC indicates that Mg anticipates the thermal degradation of the polymers but does not compromise their stability during processing. Especial emphasis is devoted to determine the effect of strain rate and Mg content on mechanical behavior, thus important information about the visco-elastic behavior and time-dependent response of the composites is obtained. Relevant for the intended application is that Mg addition increases the elastic modulus and hardness of the polymeric matrices and induces a higher resistance to flow. The elastic modulus obtained by DSI experiments shows good agreement with that obtained by uniaxial compression tests. The results indicate that DSI experiments are a reliable method to calculate the modulus of polymeric composites reinforced with micro-particles. Taking into consideration the mechanical properties results, PLA/Mg composite could be used as substitute for biodegradable monolithic polymeric implants already in the market for orthopedics (freeform meshes, mini plates, screws, pins, …), craniomaxillofacial, or spine.
authors: Centro Nacional de Investigaciones Metalúrgicas, CENIM-CSIC, Avda. Gregorio del Amo 8, 28040 Madrid, Spain; Departamento de Ciencia e Ingeniería de Materiales e Ingeniería Química, IAAB, Universidad Carlos III de Madrid, Avda. de la Universidad, 30, 28911 Leganés, Madrid, Spain. Electronic address: scifuent@ing.uc3m.es.
authors: S C
authors: SC
authors: Cifuentes
authors: Department of Control Engineering, Faculty of Electrical Engineering, Czech Technical University in Prague, Technická 2, Prague 6, Czech Republic. Electronic address: frutoemi@fel.cvut.cz.
authors: E
authors: E
authors: Frutos
authors: Instituto de Ciencia y Tecnología de Polímeros ICTP-CSIC, Juan de la Cierva 3, 28006 Madrid, Spain. Electronic address: rbenavente@ictp.csic.es.
authors: R
authors: R
authors: Benavente
authors: Grupo de Investigación ''Polímeros, Caracterización y Aplicaciones'' (U.A. del ICTP-CSIC), Universidad Politécnica de Madrid, 28006 Madrid, Spain. Electronic address: vicente.lorenzo@upm.es.
authors: V
authors: V
authors: Lorenzo
authors: Centro Nacional de Investigaciones Metalúrgicas, CENIM-CSIC, Avda. Gregorio del Amo 8, 28040 Madrid, Spain; Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina CIBER-BBN, Spain. Electronic address: jlg@cenim.csic.es.
authors: J L
authors: JL
authors: González-Carrasco
mesh_terms: D020341:Absorbable Implants; D055119:Elastic Modulus; D006244:Hardness; D008274:Magnesium; D008422:Materials Testing; D011091:Polyesters / Q000032:analysis*; D011108:Polymers / Q000032:analysis*; D014783:Viscosity
chemical_list: D011091:Polyesters; D011108:Polymers; C033616:poly(lactide); D008274:Magnesium
keywords: Biodegradable composites; Indentation tests; Magnesium; Mechanical properties; PLA