Reactive extrusion of poly(ethylene terephthalate)–(ethylene/methyl acrylate/glycidyl methacrylate)–organoclay nanocomposites

Abstract

This study was conducted to investigate the effects of component concentrations and addition order of the components on the final properties of ternary nanocomposites composed of poly(ethylene terephthalate), organoclay, and an ethylene-methyl acrylate-glycidyl methacrylate (E-MA-GMA) terpolymer acting as an impact modifier for PET. In this context, first, the optimum amount of the impact modifier was determined by melt compounding binary PET-terpolymer blends in a corotating twin-screw extruder. The amount of the impact modifier (5 wt%) resulting in the highest Young's modulus and moderate elongation at break was selected owing to its balanced mechanical properties. Thereafter, by using 5 wt% terpolymer content, the effects of organically modified clay concentration and addition order of the components on the properties of ternary nanocomposites were systematically investigated. Mechanical testing revealed that different addition orders of the materials significantly affected the mechanical properties. Among the investigated addition orders, the best sequence of component addition (PI-C) was the one in which poly(ethylene terephthalate) was first compounded with E-MA-GMA. Later, this mixture was compounded with the organoclay in the subsequent run. In X-ray diffraction analysis, extensive layer separation associated with delamination of the original clay structure occurred in PI-C and CI-P (Clay ؉ Impact Modifier followed by PET) sequences with both 1 and 3 wt% clay contents. X-ray diffraction patterns showed that at these conditions exfoliated structures resulted as indicated by the disappearance of any peaks due to the diffraction within the consecutive clay layers. POLYM. COMPOS., 28: 251-258, 2007.

Epoxy/PCL nanocomposites: Effect of layered silicate on structure and behavior

“…The enhanced efficiency of impact modifiers allows their content to be reduced. This effect was observed in both immiscible thermoplastic systems [7][8][9] and epoxies with two phase structures formed by the reaction-induced phase separation (RIPS) [10] of a modifier dissolved in an uncured resin. The enhanced mechanical performance of epoxy systems was mostly observed in liquid rubbers and clays [11][12][13] and in combinations of thermoplastics (PEEK, PEI, PES, ABS) and clays [14][15][16][17][18][19][20].…”

“…The primary shortcoming is the increase in viscosity that limits the content of the modifier. An increasing number of studies have indicated not only that nanofillers (NF) can compensate for the stiffness reduction of impact-modified polymeric systems but also that a suitable combination of NF and a polymeric modifier can also provide a synergistic effect (e.g., further increasing the material toughness) [7][8][9][10][11][12][13][14][15][16]. The enhanced efficiency of impact modifiers allows their content to be reduced.…”

“…The synergistic effect of the nanofiller consists in its complex effect on the multiphase system by reinforcement, leading also to a change in the component parameter profile combined with a significant influence on the structure and parameters of the interface. The NF influences the structure by affecting the dynamic phase behavior in the case of immiscible thermoplastics [7][8][9] and the phase separation (including RIPS) that occurs in thermosets. In both cases, the change of morphology type and dimension, including the formation of complex structures, is accompanied by an influence on the interface and crystallinity parameters [19].…”

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

“…21 Successful melt dispersion requires the presence of strong interactions between the inorganic nanofillers and the macromolecules, an appropriate stress field and an enough residence time. In the literature many works report about PET/MMT nanocomposites with enhanced tensile mechanical properties, produced via melt blending, namely: (i) higher modulus, 12,[15][16][17][18]25 (ii) higher strength, 12,14,18 and (iii) higher deformability. 14 Until now, research efforts have been devoted to the characterization of the deformation mechanism of PNCs with MMT during uniaxial stretching, as a function of the degree of delamination of MMT.…”

Structure and Mechanical Properties of Nanocomposites Based on an Amorphous Copolyester

“…The addition of an ionomer to PET enhanced both the dispersion [14][15][16] and the mechanical properties, [16] due to an enhancement of the polymer/organoclay interactions. The mechanical properties and the morphology of recycled PET, [9,16,17] and the toughening by rubber addition [18] have been studied, as well as the effect of organoclay addition on nucleation [19] and the enhancement of barrier properties. [20] In the case of poly(butylene terephthalate) (PBT)-based PNs, the clay acted as a heterogeneous nucleating agent at low content [8] but as a physical hindrance to retard crystallization at high content.…”