Development of Highly Bioactive and Mechanically Strong Starch Thermoplastic/Bioglass Composite Biomaterials

摘要

Bioglass 45S5 (BG45S5), with a granulometric distribution between 38 and 53 #mu#m, was incorporated into a biodegradable starch based polymers (starch/ethylene-vinyl alcohol blends -SEVA-C) aiming to develop composites with adequate properties for bone replacement applications. Composites with 10 and 40 percent (by weight) of Bioglass 45S5 were compound by twin-screw extrusion (TSE) and then injection moulded. SEVA-C/ hydroxylapatite (HA) composites were also produced using the same methodology for comparative purposes. The mechanical properties of the composites were evaluated in tensile tests, and their bioactivity was assessed by analysing the respective surfaces scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS) after different immersion periods in a simulated body fluid (SBF). The biodegradability of the composites was also assessed. The results obtained indicated the SEVA-C/Bioglass composites present a slightly higher stiffness and strength (a modulus of 3.8 GPa and UTS of 38.6 GPa) than SEVA-C/HA composites. The bioactivity of SEVA-C composites becomes relevant for BG45S5 amounts of only 10 percent wt. The composites were biodegradable being the results correlated with the correspondent materials compositions.