Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais, Escola de Engenharia, Bloco 2, sala 2233, Av Antonio Carlos, 6627 Pampulha, 31.270-901 Belo Horizonte, MG, Brazil.
Biomacromolecules. 2010 Mar 8;11(3):657-65. doi: 10.1021/bm901228a.
The combination of bioactive ceramics and polymers can allow the preparation of composites with tailorable mechanical properties and bioactive behavior. In these composites, bioactive ceramics can act as a source of both reinforcement and bioactivity, while the polymer matrix can add toughness and processability to the material. On the other hand, the effect of using a highly dimensional unstable phase as a reinforcing agent on the long-term properties of the composite is a major concern regarding the lifetime of possible applications. In this work, a bioactive glass-polysulfone particulate composite was prepared by hot-pressing at 215 degrees C a mixture of polysulfone and different concentrations of bioactive glass particles (Bioglass 45S5, particle size range: 125-106 microm) to yield composites having 20 and 40 vol % of bioactive glass particles. The obtained composites were exposed to a simulated body fluid at 37 degrees C for different periods of time ranging from 1 h to 60 days. After the test, the mechanical properties of the composites were investigated by a four-point bending test, while DMS (dynamic mechanical spectroscopy) was used to identify the effect of water on the structure and behavior of the composite. The interface between glass particles and the polymer was also investigated by SEM/EDX and diffuse reflection infrared spectroscopy. The results showed that a decay in the mechanical properties of the composites within the first 20 h of test can occur. Otherwise, after this initial decay, no more pronounced reduction in properties could be noted. The analyses of the fracture surface of composites tested in vitro indicated the hydration of the surface of the particles. Therefore, it was concluded that water migration through the interface of the composite causes surface dissolution of glass particles and formation of voids, which were responsible for the observed decay in mechanical properties. Composites with modified interfaces revealed less damaged fracture surfaces than composites with untreated interfaces.
生物活性陶瓷和聚合物的组合可以制备具有可定制机械性能和生物活性的复合材料。在这些复合材料中，生物活性陶瓷可以作为增强剂和生物活性的来源，而聚合物基质可以为材料增加韧性和可加工性。另一方面，使用高度尺寸不稳定的相作为增强剂对复合材料长期性能的影响是对可能应用的使用寿命的主要关注。在这项工作中，通过在 215°C 下热压混合物来制备生物活性玻璃-聚砜颗粒复合材料，混合物由聚砜和不同浓度的生物活性玻璃颗粒（Bioglass 45S5，粒径范围：125-106 微米）组成，以获得具有 20 和 40 体积%的生物活性玻璃颗粒的复合材料。将获得的复合材料在 37°C 的模拟体液中暴露不同时间，从 1 小时到 60 天不等。测试后，通过四点弯曲试验研究复合材料的力学性能，同时使用 DMS（动态力学光谱）来确定水对复合材料结构和行为的影响。还通过 SEM/EDX 和漫反射红外光谱研究了玻璃颗粒和聚合物之间的界面。结果表明，在测试的前 20 小时内，复合材料的力学性能可能会下降。否则，在初始衰减之后，不能再注意到性能的明显降低。对体外测试的复合材料断裂表面的分析表明颗粒表面的水合作用。因此，可以得出结论，水通过复合材料界面的迁移导致玻璃颗粒的表面溶解和空隙的形成，这是观察到的力学性能下降的原因。具有改性界面的复合材料显示出比具有未处理界面的复合材料更少损坏的断裂表面。
