Properties of poly(ethylene terephthalate)–poly(ethylene naphthalene 2,6‐dicarboxylate) blends with montmorillonite clay

Abstract

The production and properties of blends of poly(ethylene terephthalate) (PET) and poly(ethylene naphthalene 2,6‐dicarboxylate) (PEN) with three modified clays are reported. Octadecylammonium chloride and maleic anhydride (MAH) are used to modify the surface of the montmorillonite–Na+ clay particles (clay–Na+) to produce clay–C18 and clay–MAH, respectively, before they are mixed with the PET/PEN system. The transesterification degree, hydrophobicity and the effect of the clays on the mechanical, rheological and thermal properties are analysed. The PET–PEN/clay–C18 system does not show any improvements in the mechanical properties, which is attributed to poor exfoliation. On the other hand, in the PET–PEN/clay–MAH blends, the modified clay restricts crystallization of the matrix, as evidenced in the low value of the crystallization enthalpy. The process‐induced PET–PEN transesterification reaction is affected by the clay particles. Clay–C18 induces the largest proportion of naphthalate–ethylene–terephthalate (NET) blocks, as opposed to clay–Na+ which renders the lowest proportion. The clay readily incorporates in the bulk polymer, but receding contact‐angle measurements reveal a small influence of the particles on the surface properties of the sample. The clay–Na+ blend shows a predominant solid‐like behaviour, as evidenced by the magnitude of the storage modulus in the low‐frequency range, which reflects a high entanglement density and a substantial degree of polymer–particle interactions. Copyright © 2005 Society of Chemical Industry

In situ WAXS/SAXS structural evolution study during uniaxial stretching of poly(ethylene therephthalate) nanocomposites in solid state: Poly(ethylene therephthalate)/montmorillonite nanocomposites

“…The incorporation of MMT nanofillers in the PET polymer matrix have been made via various methods, namely: (i) in situ polymerization, [9][10][11][12][13][14][15][16][17][18][19] (ii) solvent assisted blending, [9][10][11] and direct melt blending. [12][13][14][15][16][17][18][19][20][21][22][23] Melt blending techniques are recognized as an attractive pathway to produce PNC in a commercial scale, due to: (i) the fast dispersion of nanofillers in the melt, (ii) the availability of melt compounding capacities, and (iii) the environmentally friendly preparation.1 A variety of blending apparatus were used for compounding of PET with MMT nanoparticles, specifically: (i) corotating twin-screw extruder, 12,14,15,21,22,24,25 (ii) corotating twin-screw micro extruder, 26,27 (iii) contrarotating extruder, 16 (iv) extrusion and subsequent injection moulding, 17,18,23 and direct injection molding. 17,23 However, the main limitations of melt blending methods are the delamination of MMT's layers into the polymer matrix and the thermal decomposition of the organic surfactants.…”

Nano and Hybrid Composites Based on Poly(ethylene terephthalate): Blending and Characterization

“…MMT can be easily separated and/or delaminated (exfoliated). 2,6,15,17 In most of the cases, the MMT are surface treated, thus originating organoclays with improved dispersion capability into the polymer matrices.…”

“…3,8,15,16,19 Like for many other polymers, a chosen route to prepare PET-layered silicate nanocomposites is by melt-blending techniques due to their simple and versatile processing way. 2,6,14,17 The melt-blending method is remarkable because it can produce both intercalated and exfoliated composites with a wide range of polymers. 3 In the intercalated form, the matrix polymer molecules are introduced between the ordered layers of the clay, resulting in an increase of the interlayer (gallery) spacing, but still maintaining the order; whereas in the exfoliated form, the clay layers are completely separated and dispersed within the polymeric matrix.…”

“…11,15,16 Composite materials with enhanced performance require that the polymer molecules are intercalated in the nanoclay galleries to promote their exfoliation/intercalation, that the size of clay agglomerates is substantially reduced (deagglomeration), and that a high dispersion of the nanoparticles in the polymer matrix is achieved. 4,17,18,20 The success of MMT (SCP Rockwood Additives, Moosburg, Germany) exfoliation is associated with the presence of strong interactions (degree of compatibility) between the nanoclays and the polymer chains, 17 in addition to an adequate mechanical loading and appropriate residence time. 6,18 A complete morphological characterization of PLSN is generally accomplished by the combination of transmission electron microscopy (TEM, University of Zaragoza, Zaragoza, Spain) (or high resolution scanning electron microscopy) and X-ray diffraction (XRD, University of Minho, Guimarães, Portugal) techniques.…”

Toughening of recycled poly(ethylene terephthalate) with clay‐compatibilized rubber phase

“…The ability of clay to influence structure of polymer blends is also of importance. The compatibilizing activity of clay13, 28 was successfully demonstrated for many polymer pairs but there are only few reports dealing with PET blends, in particular PET matrix systems 29–31. At the same time, the rising production of recycled bottle‐grade PET brings a valuable new low‐cost polymeric material.…”