Synthesis and dielectric properties of poly(methyl methacrylate)–clay nanocomposite materials

Abstract

Poly(methyl methacrylate) (PMMA)-clay nanocomposite (PCN) materials were synthesized through in situ intercalative polymerization. A cationic surfactant, [2(dimethylamino)ethyl]triphenylphosphonium bromide, was used as an intercalating agent with pristine Na ϩ -montmorillonite (MMT). The synthesized PCN materials were subsequently investigated by a series of characterization techniques, including wide-angle powder X-ray diffraction, Fourier transform IR spectroscopy, transmission electron microscopy, thermogravimetric analysis, and differential scanning calorimetry. Compared to pure PMMA, the PCN materials exhibit higher thermal degradation temperatures and glass-transition temperatures. The dielectric properties of PCN blending with a commercial PMMA material in film form with clay loading from 0.5 to 5.0 wt % were measured under frequencies of 100 Hz-1 MHz at 35-100°C. Significantly depressed dielectric constants and losses were observed for these PCN-blending materials.

Investigation of correlation between dielectric parameters and nanostructures in aqueous solution grown poly(vinyl alcohol)-montmorillonite clay nanocomposites by dielectric relaxation spectroscopy

“…Further, the formation of the hydrogen bonds between the PVA vinyl alcohol group and silicate oxygen force the PVA chains to create long adsorbed trains due to the atomically smooth dispersed MMT surfaces. The large reduction in ε′ value at 1 wt% MMT clay concentration in PVA-MMT clay nanocomposites also suggests that the amount of exfoliated structures is very high as compared to that of the PVA intercalated clay structures [14,15], which is the common characteristics of solution grown PCNs at very low clay concentration [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34]. The loss part ε″ spectra of complex dielectric function ( Figure 1b) reflects the presence of two relaxation processes in the PVA-MMT clay nanocomposite films over the frequency range 20 Hz-1 MHz, which can be seen in their complex plane plots (ε″ vs. ε′) (Figure 2).…”

“…This behaviour is not surprising, because in aqueous solutions the flexible PVA chain and dispersed clay exist with a variety of hydrogen bonded structures. Recently, Wang et al [20,21] investigated the dielectric properties of solution intercalated polystyrene-MMT clay and poly(methyl methacrylate)-MMT clay nanocomposite films within the frequencies of 100 Hz-1 MHz and found that loading of 1 wt% MMT clay significantly reduces the ε′ values as compared to the pure polymer film, which is mainly due to reduction in the number of aligned dipolar groups in the presence of randomly distributed exfoliated clay nanoplatelets in the polymer matrix. In PVA-MMT clay nanocomposites, the intercalation of PVA in clay galleries and exfoliation of MMT clay nanoplatelets occur simultaneously [13][14][15][16][17].…”

“…The complex dielectric function, alternating current (ac) electrical conductivity, impedance properties and electric modulus spectra of the PVA-MMT clay nanocomposite films were investigated over the frequency range 20 Hz to 1 MHz. An attempt is made to correlate the values of various dielectric parameters with structural behaviour of these nanocomposites materials to establish the use of dielectric relaxation spectroscopy as diagnostic tool for the development of on-line testing and monitoring of the nanocomposite formation in PCNs materials [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33].…”

Synthesis and characterization of in situ prepared poly (methyl methacrylate) nanocomposites

“…These nanocomposites exhibit enhanced thermal stability with greater dimensional stability, stiffness, strength, low thermal expansion and fire retardancy and also unusual magnetic, optical and electronic properties than their counterpart (Qiang et al 2004;Wang et al 2005). Nano-scale composite materials containing titanium oxides are interesting because of their potential applications in optoelectronic devices (Suzuki et al 2002).…”

Nanocomposite polymer electrolytes by in situ polymerization of methyl methacrylate: For electrochemical applications

“…These nanocomposites exhibit enhanced thermal and dimensional stability, stiffness, strength, low thermal expansion and fire retardancy and also unusual magnetic, optical, electronic properties than their counterpart. [7][8][9] Nanoscale composite materials containing titanium oxide are interesting because of their potential applications in optoelectronic devices. 10,11 A great deal of research effort has been focused on both, synthesis of high quality transparent films consisting of polymer-TiO 2 hybrid nanocomposites and their linear optical properties.…”