Structure and properties of polyethylene ionomer based nanocomposites

Abstract

Li and Zn ionomers of poly(ethylene-comethacrylic acid) were modified by two organically modified montmorillonites by melt mixing. In the nanocomposites (NCs), the increase in the loss tangent main peak temperature indicated a reduction in the mobility of the long-chain segments containing neutralized acid groups. The stack compaction observed by wide-angle X-ray scattering and transmission electron microscopy in the Cloisite 30B based NCs was attributed to the partial degradation of the surfactant and to the irreversible character of the ionexchange process of the ammonium cation of the surfactant with the Li cation. The considerable dispersion that occurred in the poly(ethylene-co-methacrylic acid) zinc salt (PEMAZn)/Cloisite 20A (20A) NCs was attributed to the high volume of the surfactant, which reduced undesired interactions between the inorganic clay surface and the ionomer. The ductile nature of the matrix remained in all of the NCs, and the increase in the modulus of elasticity of the PEMA-Zn/ 20A NCs reached a value five times greater than that of the PEMA-Zn matrix. The results suggest that this ionomer is suitable for use both as a matrix for 20A NCs and as a compatibilizer of polyolefin-based NCs with 20A.

Polypropylene/clay nanocomposites: An innovative one-pot process

“…Enhancement of clay dispersion was reported using polyethylene (PE) ionomers ( i.e . ammonium carboxylate polyampholytes prepared from polyethylene (PE)‐graft‐maleic anhydride (PE‐ g ‐MA)) as matrix and using poly(ethylene‐co‐methacrylic acid) ionomer as matrix or as compatibilizer in PE/organomodified clay nanocomposites and in PP/organomodified clay nanocomposites . Similar improvement of clay dispersion in PP/organomodified clay nanocomposites was obtained using, as compatibilizer, PP‐ g ‐MA ionomer neutralized by potassium hydroxide .…”

Engineering Polypropylene–Calcium Sulfate (Anhydrite II) Composites: The Key Role of Zinc Ionomers via Reactive Extrusion

“…As was mentioned elsewhere, the good mechanical properties of PP–AII composites can be ascribed not only to the effects of crosslinking, due to the formation of clusters of Zn ionomer, but also to the existence of good compatibility between the PP matrix and filler. Additionally, it is not excluded that the pendant ionic groups in the ionomer might increase the polarity of PP [ 66 , 67 , 89 ], and this plays a key role in improving the interactions with AII. As in the case of other ionomers, Zn ionomer can act as a compatibilizer, allowing a finer filler dispersion and better adhesion between the PP and AII microparticles [ 66 , 67 , 90 ].…”

“…For compatibilization and to obtain enhancements of proprieties, the PP/AII compositions have been modified with selected reactive modifiers, such as PP functionalized/grafted with maleic anhydride (PP-g-MA), and an ionomeric monomeric additive, zinc diacrylate. In fact, fillers such as talc, calcium carbonate, and AII are polar in nature; therefore, for better interfacial adhesion (PP–filler), the modification of PP can be accomplished by attaching polar groups onto the PP backbone, e.g., via the addition of PP-g-MA [ 64 , 65 ], or using metallic ionomers (i.e., zinc diacrylate to lead to Zn ionomer) [ 66 , 67 ], experimental methods often considered in prior studies.…”

Dispersion and mechanical properties of a nanocomposite with an organoclay in an ionomer‐compatibilized LDPE matrix

“…The maximum MMT content was low (4.4%), and the phase behavior of the matrix was not reported. In a previous report on the dispersion of OMMT's using a single MMT content,29 pure Pema‐Zn was shown to be more effective than the Pema‐Li in dispersing organoclays. Moreover, it was shown that the Cloisite 20A organoclay was the most adequate organic modification for achieving dispersion when using this ionomer.…”