Thermal and Dynamic Mechanical Properties of Low Density Polyethylene-Silica Nanocomposites: Effect of Zinc-Ion Coating on Nanosilica

摘要

Low-density polyethylene (LDPE)/silica nanocomposites were developed by conventional melt blending in a sigma internal mixer.Two types of composite,each with 2.5 wt% filler,were produced.The first was obtained by melt blending nano-silica with LDPE in a co-rotating sigma internal mixer.The second was obtained by melt blending the same LDPE,with zinc-ion coated nano-silica.In the case of zinc-ion coated nano-silica- filled LDPE,wide-angle X-ray diffraction (WAXD) showed a decrease in the interplanar distance and an increase in lamellar crystal size when compared to nano-silica filled LDPE.DSC and TGA results showed the zinc-ion coated nano-silica filled LDPE has higher thermal stability,heat of fusion,melting temperature and crystallinity than LDPE filled with nano-silica.AFM surface topography images showed a uniform surface and lower roughness in the case of zinc-ion coated nano-silica filled LDPE than nano-silica filled LDPE.Furthermore,the zinc-ion coating over nano-silica showed improvements in storage modulus E',static modulus and thermal properties - a 26% increase in static elastic modulus and a rise in degradation onset temperature from 337 deg C to 355 deg C,in comparison to the nano-silica.