عنوان مقاله [English]
نویسندگان [English]چکیده [English]
The effect of microwave thermal treatment on mechanical properties of composites made from MDF dust-polypropylene was investigated. In this regard, nanoclay (Cloisite 15A) was added in three different (2, 4 and 6 %wt) levels into the composites. Furthermore, polypropylene (PP) was used as a matrix material and maleic anhydride-grafted polypropylene (MAPP) was used as coupling agent at 4%wt. The medium density fibreboard (MDF) dust was used as lignocellulosic material in the present study. Test samples were made, using extrusion process (twin screw), as granules. Then, samples with dimensions 30×20×1 cm were prepared with 1 g/cm3 nominal density for the polymer composites using hot pressing method. The bending strength and impact strength were measured according to the technical specifications CEN/TS15534:2007 and D-4495 regulation of ASTM standard, respectively. Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) techniques were employed to evaluate the extent of intercalation and exfoliation of silicate layers in the nanocomposites. Finally, the mechanical tests of flexural strength, flexural modulus and impact strength were performed on the samples. The results showed that the highest flexural strength, flexural modulus and impact strength were obtained at level 2 wt% nanoclay particles. The mechanical strength of the samples that were treated by microwave radiation was the highest. Also, X-ray diffraction studies showed increases in the interlayer spacing of silicate layers and intercalation of polymer chains between the clay layers. Scanning electron microscopy results showed that in the nanocomposites treated by microwave radiation, MDF dust was desirably compounded with thermoplastic materials.