Morphological and Rheological Properties of Polyamide 6/Poly(propylene)/Organoclay Nanocomposites

Abstract

Summary: Polyamide 6 (PA6)/Poly(propylene) (PP)/organoclay (octadecylamine intercalated montmorillonite) systems with and without compatibilizer (maleated poly(propylene) and ethylene/propylene‐based rubber (PPgMA and EPRgMA, respectively)) were produced by extrusion melt blending and the clay dispersion was characterized by transmission electron microscopy (TEM) and X‐ray diffraction (XRD). The rheological behaviour of the nanocomposites was determined by various methods, viz melt flow index (MFI), capillary and plate/plate rheological measurements. Attempts were made to trace the rheological parameters that reliably reflect the observed changes in the clay dispersion. It was found that some parameters in the viscoelastic range derived from frequency sweep measurements using a plate/plate rheometer are a suitable indicator for changes in the clay dispersion. High initial viscosity with a strong reduction as a function of frequency was attributed to improved clay exfoliation. The latter was also reflected by a high initial shear storage modulus (G′) along with its small change with the frequency.Variation of the storage modulus (G′) as a function of frequency for the PA6/PP nanocomposites. Note: this figure also indicates how the slopes at low and high shear rates were determined.imageVariation of the storage modulus (G′) as a function of frequency for the PA6/PP nanocomposites. Note: this figure also indicates how the slopes at low and high shear rates were determined.

Polyamide blend-based nanocomposites: A review

“…The higher G! and the smaller the related slope, as well as the higher "* and its higher related slope, the better the clay dispersion is [84]. Mojarrad et al [85] studied the influence of a nanoclay on the rheological properties of PA6/ABS nanocomposites (with ethylene-n butyl acrylate-carbon monoxidemaleic anhydride as a compatibilizer).…”

“…Furthermore, the clay layers were preferentially embedded in a PA6-grafted polyolefin phase, formed via chemical reactions between the primary and secondary amines of the PA6 and the anhydride groups of the maleated polypropylene (MAH-g-PP) and ethylene/propylene rubber (EPR-g-MA), respectively. The melt viscosity of the compatibilizer (EPRg-MA >> MAH-g-PP) was suggested to also affect the dispersion state of the organoclay [84]. The strength and stiffness of the PA6/PP nanocomposites were significantly improved in the presence of MAH-g-PP.…”

Polyethylene/synthetic boehmite alumina nanocomposites: Structure, thermal and rheological properties

“…Moreover, the difference in the melt viscosity and the G′ value at low shear rates are often considered as indicators for the fine dispersion and strong particulate filler/matrix interactions (e.g. [23,24]). However, this is clearly not the case when having a look at the graphs depicted in Figures 10 and 11.…”

Effect of injection molding parameters on nanofillers dispersion in masterbatch based PP-clay nanocomposites

“…plot illustrated the profound interaction between the silicate platelets and their trend to form a three dimensional superstructure. According to Chow et al [35], the stability of the clay dispersion can be related to the terminal slope, i.e. the higher the slope the less stable the clay dispersion.…”