Wood filled high density polyethylene composites with nanosilica containing
Polimery 2012, No 3, 192
The influence of silica containing immobilized nanosilver (SGS-Ag) (Fig. 1, Table 1) on the structure, thermal (Table 2) and mechanical (Tables 3, 4) properties of wood-filled high density polyethylene composites (WPC) was investigated. All materials were compounded in a co-rotating twin-screw extruder and then injection molded. The composites were characterized with SEM (Figs. 2, 4, 5) and DSC (Figs. 6, 7) methods. The thermal decomposition was studied by TGA (Figs. 12—14, Table 5). The mechanical properties and heat distortion temperature were also determined. The addition of silica in the presence of maleated high density polyethylene (MPE-HD) improves adhesion between the PE-HD and wood fiber. Storage modulus values of prepared composites containing nanosilica measured by DMTA were sensitive to the microstructure of the nanocomposites (Fig. 8). It was found out, that contents and size of nanosilica particles have great impact on nanocomposites properties. Higher silica contents resulted in higher storage modulus, proving that the material became stiffer. Crystallization rates and crystallinity were found to increase by adding MPE-HD as well as nanosilica. The thermal stability of WPC containing SGS-Ag was better compared to either WPC or neat PE-HD. The gradual enhancement in tensile and flexural strengths of the wood-filled PE-HD composites containing MPE-HD was observed. The addition of silica nanoparticles to the wood-filled PE-HD composites increased tensile and flexural modulus, and impact strength pointing to a synergistic effect arising from the presence of the reinforced PE-HD phase, containing high amounts of the finely dispersed wood fiber.