The effect of montmorillonite modification and the use of coupling agent on mechanical properties of polypropylene–clay nanocomposites

Abstract

In this work, polypropylene (PP)–clay nanocomposites obtained by melt blending were investigated. Different commercial montmorillonites (MMTs), such as unmodified MMT, octadecyl ammonium-modified MMT, and dimethyl dialkyl ammonium-modified MMT, have been used. Maleic anhydride–polypropylene (MAPP) copolymer has been used as a coupling agent, and the effect of clay modification as well as MMT: MAPP ratio on final nanocomposites performance was studied. The transmission electron microscopy was used to evaluate the incorporation of clays into the PP matrix. The isothermal crystallization behavior of neat PP and different nanocomposites was studied by differential scanning calorimetry and polarized optical microscopy. Only nanocomposites based on organically modified MMT showed mechanical performance improvements. Nanocomposite reinforced with 5 wt% of organically modified MMT without MAPP showed modulus and strength values of 871 and 29.3 MPa, respectively, these values being higher, around 23% and 4.6%, respectively, than modulus and strength values of neat PP. The incorporation of MMT into the PP matrix produced an increment on the crystallinity rate with respect to neat PP. The half crystallization time of nanocomposites without MAPP was, at least, two times faster than for a neat PP system.

Melt rheological behaviour of high-density polyethylene/montmorillonite nanocomposites

“…polymers and temperature can be investigated from the semi-logarithmic Arrhenius expression equation (6). The value of activation energy (DE) for HDPE, HDPE/MMT and HDPE/HDPE-g-MA/MMT nanocomposites was determined from the slope of log corrected h versus 1/T curves (Figure 6).…”

“…15,16 So as to acquire a superior chemical compatibility between clay and polyethylene, the utilisation of organoclay with high hydrophobicity is prescribed and a few researchers attempted to utilise various organo-modifiers for functionalisation of clay and some researchers used compatibilisers to improve the polarity of polyolefins so that effective interaction can be achieved between polymer and clay. 17,18 Recently, Arbelaiz et al 6 have investigated the effect of MMT modification as well as MMT: maleic anhydride-polypropylene (MAPP) ratio on the mechanical properties of PP-clay nanocomposites.…”

“…In the MMT clay structure an octahedral sheet of aluminum or magnesium hydroxide is sandwiched in between two silica tetrahedral sheets. 6 High-density polyethylene (HDPE) is one of the most commonly utilised thermoplastic polymers in huge quantity. However, there are some limitations in its applications due to its restricted barrier properties to oxygen and different hydrocarbon fuels like gasoline, diesel and kerosene, poor resistance to crack propagation and poor oxidative degradation stability.…”

“…In the MMT clay structure an octahedral sheet of aluminum or magnesium hydroxide is sandwiched in between two silica tetrahedral sheets. 6…”

Functional Elastomeric Copolymer Membranes Designed by Nanoarchitectonics Approach for Methylene Blue Removal

“…In contrast, the presence of maleic anhydride (2 wt%) in the copolymer provided reactive centers for covalent coupling reactions [33,34], and enabling condensation with primary amines [35]. Accordingly, recent reports used the amine/maleic anhydride coupling strategy for assembling a large number of polymer blends [36,37] and composites [38][39][40]. In this work, homobifuctional bisamine linkers were covalently reticulated with maleic anhydride blocks of PSEBMA, yielding elastomeric membranes through amide and imide bonds.…”