A simple approach for a PEG-b-PLA-compatibilized interface in PLA/HAp nanocomposite. From the design of the material to the improvement of thermal/mechanical properties and bioactivity

摘要

A simple approach towards the compatibilization of polylactide (PLA) and hydroxyapatite (HAp) nanoparticles nanocomposites is here presented. An amphiphilic diblock copolymer, consisting of poly(ethylene glycol) (PEG) and PLA block was prepared and used to form an interphase between PLA matrix and HAp nanofiller. This copolymer was next mixed with HAp to intimly deposit PEG block on the HAp surface. Effective hydrophobization via PLA chains presence on the surface of the modified nanoparticles was attested via dispersion test in chloroform. Finally, the as modified HAp nanoparticles were blended in PLA. Thermal analyses showed a T-g superior to human body temperature. Dynamic mechanical and morphological analysis attested for improved dispersion and deagglomeration state of the nanoparticles in PLA. Interfacial mechanical properties studies recorded an increase of 150 in compressive modulus compared with neat PLA. In vitro bioactivity assay showed beneficial effect on the mineralization process in simulated body fluid when the interphase is created. This improvement of mechanical properties and bioactivity combined with a simple production process as extrusion make these materials suitable choice for potential load bearing applications.