Effect of ionomer on clay dispersions in polypropylene‐layered silicate nanocomposites

Abstract

In this study, polypropylene (PP)/clay nanocomposites containing different concentrations of ethylene-methacrylic acid ionomer (i.e. Surlyn 1 ) were prepared, and the effect of ionomer on clay dispersion was studied via WAXD, rheology, SEM, and TEM. The role of the ionomer in the nanocomposites was compared with that of maleic anhydride grafted PP (PP-g-MA), which has been widely used as a compatibilizer in making PP/ clay nanocomposites. With an increase in the concentration of compatibilizer, the position of d 001 peak of OMMT shifted toward a lower angle for PP-g-MA system, while the position remained almost unchanged for Surlyn system, in which a larger interlayer spacing (d 001 ) was found with respect to the former. In rheology, the addition of the ionomer led to a gradual increase in both moduli and complex viscosity, and the nonterminal behavior at low frequency was observed in both systems. In addition, the ternary hybrid containing 20 wt % Surlyn achieved the largest enhancement in relative viscosity, which was more than that of the nanocomposite prepared from pure Surlyn or pure PP, presumably indicative of the existence of strong interaction between the components. Finally, SEM and TEM micrographs demonstrated that exfoliated structure was preferred for PP/Surlyn/OMMT hybrids, while intercalated morphology for PP/PP-g-MA/ OMMT.

Different Effects of Water and Glycerol on Morphology and Properties of Poly(lactic acid)/Soy Protein Concentrate Blends

“…rheological characterization is regarded as an effective tool to reveal the global dispersion state of the blend. [27][28][29] Figure 2 shows complex viscosity (h à ), storage modulus (G 0 ), and loss modulus (G 00 ) of PLA and its SPC blends with varying concentrations of water and glycerol at 175 8C. The addition of SPC significantly increased the complex viscosity [ Figure 2 Figure 2(a)], in contrast to the neat PLA which showed constant viscosity at low frequencies (v < 10 rad Á s À1 ).…”

Mechanical properties, morphology, and crystal structure of polypropylene/chemically modified attapulgite nanocomposites

“…The toughness of PP could be improved with the addition of elastomer at the expense of its strength. To address these concerns, PP/clay nanocomposites have been studied for several years as a solution 6–17. However, it is still a challenge to prepare PP/clay nanocomposites with well‐exfoliated structures.…”

Compatibilization of PP/PAE blends by means of the addition of an ionomer

“…Maleic anhydride‐grafted PP (PP‐ g ‐MA) has been used in mixtures of PP with polyamides [22–25], epoxy [26–28], EVOH [7, 15, 29], and organoclays [21, 30–33], among others. In the last decade, ionomers have been successfully used to compatibilize immiscible polymer blends [12, 13, 34–47] as well as to improve the dispersion of the organically modified montmorillonite clay in polyesters [48, 49]. In the case of PP‐based blends, different kinds of ionomers have been used to compatibilize them.…”

“…In the case of PP‐based blends, different kinds of ionomers have been used to compatibilize them. Thus, ionomers of poly(ethylene‐ co ‐methacrylic acid) (PEMA) have been used in PP‐based nanocomposites [34] and in blends of PP with liquid‐crystalline polymers (LCPS) [36] and EVOH [12, 13, 39, 40]. Ionomers of poly(ethylene‐ co ‐acrylic acid) have been used in PP/LCP blends [35], ionomers of poly(ethylene‐methacrylic acid‐isobutylacrylate) in PP/PA6 blends [37, 38], and liquid‐crystalline ionomers in blends of PP with both PA and PBT [41–43].…”