Controllable synthesis of the Al4B2O9 nanowhisker and their applications in reinforced polyhydroxyalkanoate composites

Abstract

Large quantities of aluminum borate (Al₄B₂O₉) nanowhiskers have been successfully synthesized by sol–gel and post-thermal-treatment methods. A series of experiments have been conducted to obtain an optimum condition for generating nanoscale precursor for the synthesis of Al₄B₂O₉ nanowhiskers with an average diameter of 20–40 nm and length of several hundred nanometers, respectively. With decreasing boron content, the crystallized temperature is reduced, and the structure of Al₄B₂O₉ phase is different in the Al₂B₃ and Al₂B system. In addition, the effects of Al₄B₂O₉ nanowhiskers on the mechanical properties of biodegradable polyhydroxyalkanoate (PHA) have been studied. It is worth noting that with adding the 0.6 wt% Al₄B₂O₉ nanowhiskers, the mechanical properties of PHA composites are improved, the elongation to break increased by 13.5%, the ultimate tensile increased by 106.8% and yield strength increased by 190% compared with the pure PHA.