Design and preparation of high-aspect-ratio zinc borate whiskers and their effects on mechanical properties of PP nanocomposite

Well-dispersed, high-aspect-ratio 4ZnOB(2)O(3)H(2)O whiskers (4ZnOB(2)O(3)H(2)O(HARw)) were synthesized by a facile hydrothermal method with the aid of ZnSO(4)7H(2)O. The formation mechanism was investigated, and the results showed that Zn2+ and SO42- ions played a crucial role in the control of 4ZnOB(2)O(3)H(2)O(HARw) extended along [010] direction. X-ray diffraction (XRD) analysis, high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), and thermogravimetry (TG)-differential scanning calorimetry (DSC) results confirmed that the powder was 4ZnOB(2)O(3)H(2)O. Scanning electron microscopy (SEM) and TEM showed that the average aspect ratio of the product was about 100. Nanocomposites of surface-modified 4ZnOB(2)O(3)H(2)O(SM-HARw)/PP were prepared and their mechanical properties measured. The results suggested that the mechanical properties of 4ZnOB(2)O(3)H(2)O(SM-HARw)/PP composites were superior to composites made with low-aspect-ratio whiskers (4ZnOB(2)O(3)H(2)O(SM-LARw)), which displayed poorer mechanical properties even at low addition.