2006 Volume 24 Pages 73-80
Montmorillonites (Mt's) modified by boronic acid derivatives were filled in poly (vinyl alcohol)(PVA), and the microstructure and mechanical properties of PVA/Mt nanocomposites were investigated. Two types of boronic acid were used : 4-aminophenylboronic acid (4AP) and 4-aminomethylphenylboronic acid (4AMP). It was confirmed by the X-ray diffraction that the interlayer spacing of the Mt modified by 4AP (4APMt) was extended to 16.04Åwhile the spacing of unmodified Mt was 12.26Å. By 4phr filling the 4APMt, the tensile modulus (2.7GPa) and tensile strength (67MPa) of PVA have increased to 3.6GPa and 97MPa, respectively. The 4APMt-filled PVA has also exhibited the increase of storage moduli over the wide range of temperature, the enhancement of glass transition temperature, and the lower tanδ value at peak temperature. And the 4APMt-filled PVA has also showed remarkably lower water absorption property compared with PVA matrix and 4AMPMt-filled PVA. These properties are considered due to the uniform dispersion of 4APMt's in the PVA matrix and the exfoliated and/or intercalated microstructures of 4APMt's confirmed by the transmission electron microscopy. These results suggest the strong bond (monodiol complex) formation between the 4APMt and PVA matrix.
