Effect of the crystallization of bioactive glass reinforcing agents on the mechanical properties of polymer composites

Polymer composites based on the introduction of bioactive materials into polymer matrices can combine mechanical with bioactive properties suitable for many potential biomedical applications. In this work, glass-ceramics derived from the crystallization of bioactive glasses were tested as reinforcing agents in polymer composites. The kinetics of crystallization of soda-lime silica glasses containing phosphorous was studied to define conditions for obtaining glass-ceramics having different microstructures. This type of glass can be used in biomedical applications due to its ability to bind to bone (bioactive behavior). Evaluation of the mechanical properties of glass-ceramic bodies derived from bioactive glasses has allowed us to determine the relationship between microstructure and properties. A particular microstructure capable of leading to fine grained glass-ceramics with enhanced properties was then reproduced in bioactive glass particles. Thus, bioactive glass particles were crystallized to different levels and used as reinforcing agents in polymer (polysulfone) composites. Mechanical properties of composites were evaluated using a four-point bending test. Glass-ceramic reinforced composites showed higher elastic modulus than glass reinforced composites. Therefore, crystallization of silicate glasses used as reinforcing agents in polymer matrices is a possible way to enhance the mechanical properties of composites. Polymer composites having bioactive glass-ceramic particles display some mechanical properties comparable to human cortical bone.