Organoclay Nanocomposites from Ethylene–Acrylic Acid Copolymers

Abstract

Summary: A study of the structure–property relationships for nanocomposites prepared by melt compounding from ethylene–acrylic acid copolymers of varied composition and molecular architecture, and organoclays modified with different ammonium ions has been made by DSC, POM, SEM, TEM, WAXD, and rheological and mechanical tests. Within the series of clays investigated, the best levels of dispersion were displayed by those organically modified with quaternary ammonium ions containing two long alkyl tails. The relevant nanocomposites were shown to possess mixed exfoliated and intercalated morphology. The spacing of the intercalated clay stacks, most of which comprise few silicate layers, was found to be independent of clay loading, in the range of 2–50 phr, and to change with the molecular architecture of the matrix polymer. An indication that the excess surfactant present in some of the clays, and the organic material added in others to expand the interlayer spacing, were expelled from the clay galleries during melt blending and acted as plasticisers for the matrix polymer, was obtained from WAXD and rheological characterisations.TEM micrograph of the nanocomposite of EAA1 with 11 phr of 15A.magnified imageTEM micrograph of the nanocomposite of EAA1 with 11 phr of 15A.

A Two‐Step Method Based on Micromechanical Models to Predict the Young's Modulus of Polymer Nanocomposites

“…[3][4][5][6][7][8][9] The contribution of interphase to mechanical properties of nanocomposites is considerable, due to the high interfacial area at polymernanoparticles interfaces. [10][11][12][13][14][15][16][17][18][19][20] It was reported that the interphase volume fraction exceeds the nanoparticle volume fraction in some samples demonstrating that the mechanical properties are significantly improved by both nanoparticles and interphases. [21] Therefore, many researchers have studied the interphase properties and its contribution to the mechanical properties of polymer nanocomposites.…”

Comparative study of nanocomposites of polyolefin compatibilizers containing kaolinite and montmorillonite organoclays

“…3(e,f)] a really bad dispersion can be seen for both types of clays (immiscible system). However, as previously reported by other authors, 41 ethylene-acrylic acid copolymers can be good matrices to disperse organoclays. In our case, the reason for the agglomeration of the clays could be the high content of acrylic acid groups (17%) that contain the particular copolymer used, perhaps making the polymer too polar for a good compatibilization with the organoclays.…”

Effect of different dispersing additives on the morphology and the properties of polyethylene-based nanocomposite films

“…The powder samples were incorporated in KBr. 13 C cross-polarization magic-angle spinning nuclear magnetic resonance ( 13 C de-coupled { 1 H} CP-MAS NMR) spectra were obtained at room temperature on a Bruker Avance II 400 MHz (9.4 T) spectrometer (Bruker, Ettlingen, Germany) operating at 100.63 MHz for the 13 C nucleus with a MAS rate of 13 kHz for 1024 scans, a contact time of 1.5 µs, and a repetition delay of 1.5 ms.…”

“…When polymer melt and filler are not well adherent, e.g. in the case of a non-polar matrix such as polyolefins containing polar particles such as nanoclays, use of an adhesion promoter or compatibilizer, having polar groups is necessary [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. In order to modify the clay morphology and consequently the final macroscopic properties in clay filled polyethylene, different commercial compatibilizers have been used.…”

“…Sánchez-Valdes et al [11] have used Zn-neutralized carboxylate ionomer, while, Shah et al [12] used Na-neutralized poly(ethylene co-methacrylic acid), both Surlyn ® by DuPont, in LDPE/clay nanocomposite formulation. Filippi and coworkers [13][14] have used as a compatibilizer, the ethylene-acrylic acids copolymers (Et-g-AA), namely Escor ® by Exxon-Mobil. Xu et al [15] have prepared HDPE/clay nanocomposites using a HDPE-g-AA co-polymer.…”