Morphology, thermal and mechanical behavior of polypropylene nanocomposites toughened with poly(ethylene‐co‐octene)

Abstract

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

Morphological, viscoelastic and mechanical characterization of polypropylene/exfoliated graphite nanocomposites

“…The range between -10 and 30 °C (β-transition) corresponds to the glass-rubber transition (Tg) of PP. The transition between 60 and 120 °C can be related to the movement of intracrystalline amorphous segments (α-relaxation) [18,19] . In addition, Figure 4 demonstrates a reduction of the intensity and a small dislocation of the β transition to higher temperatures (approximately 3 °C) with the EG addiction relative to neat polypropylene.The intensity decrease effect could be associated with the reduction of the motion of the amorphous segments due hindrance by the graphite, or in other words, an increase in the elastic component of the material.…”

Rheology of Polymers with Nanofillers

“…• C] significantly affected the relative moduli below and above T g [Lim et al, 2006]. Thus, at 1Hz and 5 K/min, in the absence of TPE, E ′ r = 1.57 and 1.38 at 193 and 293 K, respectively, while in its presence E ′ r = 1.38 and 1.13, respectively, at these temperatures.…”

Weld line behaviour of exfoliated and toughened polypropylene layered silica nanocomposites

“…Literature has some studies regarding the preparation of PP-organoclay nanocomposites having a mixture between intercalated and partially exfoliated structures [12][13]. Moreover, although some benefits are gained with these structures, decrease in tensile ductility of the resultant nanocomposites especially at low temperatures was tried to be overcome via poly(ethylene-co-octene) (PEOc) copolymer addition for forming rubber toughened PP [14]. However, even the optimized amounts of the organoclay, PP-g-MAH and PEOc did not give both the desired impact resistance and exfoliation to the nanocomposites.…”