Effect of Oligomeric-Modified Montmorillonite on Morphology and Properties of Polycarbonate/ Montmorillonite Nanocompqsites

摘要

Low-molecular-weight copolymers of styrene and vinyl-benzyl ammonium salts (oligomeric surfactant) were used to modify montmorillonite (MMT). The oligomeric-modified MMT showed good thermal stability, which made it suitable to be used for preparing polycarbona-te(PC)/MMT nanocomposites at high temperature. A different series of PC/MMT nanocomposites had been prepared by melt processing using a twin screw extruder. The effect of oligomeric surfactant structure and clay loading on the morphology, mechanical property, thermal stability, and color appearance of the nanocomposites were explored. The results of X-ray diffraction and transmission electron microscopy analyses indicated that the PC/MMT nanocomposites had partially exfoliated structures. The PC/MMT nanocomposites were found to retain light colored, which was important for optical application. Compared to neat PC, the nanocomposites showed better properties of thermal stability and heat insulation. The mechanical properties of the nanocomposites are significantly enhanced by incorporating clay into the PC matrix. The tensile strength of nanocomposites with 2 wt% clay content was up to 55 MPa, which was much higher than that of the neat PC (37 MPa). The maximum tensile modulus value was 19% higher than that of neat PC