Rubber‐toughened polypropylene (PP) nanocomposites containing organophilic layered silicates were prepared by means of melt extrusion at 230 °C using a co‐rotating twin‐screw extruder in order to examine the influence of the organoclay and the addition of PP grafted with maleic anhydride (PPgMAH) as a compatibilizer on the morphological, mechanical and thermal properties. The mechanical properties of rubber‐toughened polypropylene nanocomposites (RTPPNCs) were studied through tensile, flexural and impact tests. Scanning electron microscopy (SEM) was used for investigation of the phase morphology and rubber particles size. X‐ray diffraction (XRD) was employed to characterize the formation of nanocomposites. The thermal properties were investigated by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The dynamic mechanical properties were examined by using dynamic mechanical analysis (DMA). From the tensile and flexural tests, the optimum loading of organoclay in RTPP was found to be 6 wt%. The optimum loading of PPgMAH, based on the tensile and flexural properties, was also 6 wt%. The increase in the organoclay and PPgMAH content resulted in a severe embrittlement, manifested by a drop in the impact strength and tensile elongation at break. XRD studies revealed that intercalated RTPPNCs had been successfully prepared where the macromolecular PP segments were intercalated into the interlayer space of the organoclay. In addition, the organoclay was dispersed more evenly in the RTPPNC as the PPgMAH content increased. TGA results revealed that the thermal stability of the RTPPNC improved significantly with the addition of a small amount of organoclay. Copyright © 2006 Society of Chemical Industry

Rubber-toughened polypropylene (PP)/orgMontmorillonite (org-MMT) nanocomposite with polyethylene octene (POE) copolymer were compounded in a twinscrew extruder at 230°C and injection-molded. The POE used had 25 wt % 1-octene content and the weight fraction of POE in the blend was varied in the range of 0 -20 wt %. X-ray diffraction analysis (XRD) revealed that an intercalation org-MMT silicate layer structure was formed in rubbertoughened polypropylene nanocomposites (RTPPNC). Izod impact measurements indicated that the addition of POE led to a significant improvement in the impact strength of the RTPPNC, from 6.2 kJ/m 2 in untoughened PP nanocomposites to 17.8 kJ/m 2 in RTPPNC containing 20 wt % POE. This shows that the POE elastomer was very effective in converting brittle PP nanocomposites into tough nanocomposites. However, the Young's modulus, tensile strength, flexural modulus, and flexural strength of the blends decreased with respect to the PP nanocomposites, as the weight fraction of POE was increased to 20 wt %. Scanning electron microscopy (SEM) was used for the investigation of the phase morphology and rubber particles size. SEM study revealed a two-phase morphology where POE, as droplets was dispersed finely and uniformly in the PP matrix.

A series of compatibilized polyamide 6/polypropylene (PA6/PP) blends, of composition 70/30, 50/50, and 30/70 have been prepared in a twin screw extruder followed by injection molding. The four types of PA6/PP blends involved are the neat PA6/PP blends, PA6/PP/ethylene-octene copolymer (polyolefin elastomer, POE), PA6/PP/organoclay, and PA6/PP/POE/organoclay. Tensile, flexural, and Izod impact test are performed on these blends. The morphology of the blends is characterized by scanning electron microscopy (SEM). The mechanical properties of the blends are found to be strongly dependent on the PA6/PP blend ratio. For any blend system, with the increase in PP concentration, the strength and stiffness decreases, while the toughness increases. The incorporation of 4 wt% organoclay into PA6/PP blends significantly increases the modulus and strength but with corresponding reductions in impact strength. Conversely, the incorporation of POE increases the toughness, while the strength and stiffness decrease. However, PA6/PP blends containing both organoclay and POE elastomer are shown to have the potential to be more rigid and tougher than the neat PA6/PP itself. Blend ratio and presence of organoclay are found to influence the morphology (e.g., POE particle size and distribution) of POE toughened nanocomposites systems. A finer particle size and better distribution of POE elastomer has been observed in high PP concentration PA6/PP blends and organoclay filled PA6/PP blends.

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Rubber toughened polypropylene (PP) nanocomposites (RTPPNC) containing organophilic layered silicates were prepared by means of melt extrusion at 230uC using a co-rotating twinscrew extruder in order to examine the influence of the organoclay and polyethylene octene (POE) as filler and impact modifier, respectively, on mechanical and fracture properties. The mechanical properties of RTPPNC were studied through tensile, flexural and impact tests. The strength and stiffness of RTPPNC were improved significantly with an increase in the clay content, in the presence of maleic anhydride modified PP (PPgMAH). From the tensile and flexural tests, the optimum loading of organoclay in impact modified PP was found to be 6 wt-%. Conversely, the stiffness and strength of the blends decreased with respect to pure PP as the concentration of POE in the blends was increased. The essential work of fracture (EWF) method was also used to evaluate the fracture toughness of the RTPPNC. EWF measurements indicated that the specific essential work of fracture (w e