High‐performance polyimide–clay nanocomposite materials based on a dual intercalating agent system

BACKGROUND: Polymer–clay nanocomposites (PCNs) have attracted considerable interest in recent years owing to their unique physical and chemical properties that lead to a wide range of applications. A series of PCN materials consisting of polyimide and layered montmorillonite (MMT) clay were successfully prepared by in situ polymerization. RESULTS: Silicate layers are better dispersed in polymer matrices when dual intercalating agents (hexadecyltrimethylammonium bromide–4,4′‐oxydianiline) are applied for MMT modification according to wide‐angle X‐ray diffraction and transmission electron microscopy studies. Effects of single and dual intercalating agents on thermal stability, mechanical strength and the molecular barrier of PCN materials consisting of organo‐modified MMT were studied by means of thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analyses, gas permeability analysis and vapor permeability analysis. CONCLUSION: Improved thermal and mechanical stabilities, as well as barrier properties were observed for the PCN materials containing dual intercalating agent‐modified MMT. Copyright © 2008 Society of Chemical Industry     

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

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⁺‐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. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2175–2181, 2005     

Characterization of latex-based isotactic polypropylene/clay nanocomposites

Polypropylene/clay nanocomposite (PCN) containing 1 wt% organo-modified clay was prepared by latex technology, previously successfully applied for preparation of carbon nanotubes (CNTs)/polymer composites. The level of dispersion of organoclay and the microstructure of the resulting PCNs were characterized by means of X-ray diffraction analysis, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The obtained results have demonstrated that the latex technique represents a promising method for preparation of PP/clay nanocomposites with good dispersion of exfoliated nanoclay particles. The influence of clay nanoparticles on nonisothermal crystallization of PCN was investigated by DSC. The crystallization onset temperature of the matrix rises for about 5 °C when crystallizing from the quiescent melt. Improved thermal stability of PP/nanoclay was observed as evaluated by TGA. The dynamic mechanical analysis reveals an increase in storage modulus of PP matrix in the nanocomposites for 30% over a temperature range, indicating an increase in the stiffness of the material with the addition of organically modified clay.     

Mechanical properties of polystyrene‐montmorillonite nanocomposites—Prepared by melt intercalation

A series of polymer‐clay nanocomposite (PCN) materials, consisting of thermoplastic polystyrene (PS) sample and dispersing inorganic organoclay platelets, were successfully prepared. First, organoclay was prepared by performing cationic exchange reactions between the sodium ions existing in the interlayer region of the clay mineral and intercalation agent, followed by dispersing the organophilic clay into a PS basis through the melt intercalation approach performed by a twin‐screw mixing method. The as‐prepared PCN materials in the form of a pellet subsequently characterized using the powder X‐ray diffraction (XRD) and the transmission electron microscopy (TEM). In this study, it is found that the wear resistance of PS to be effectively enhanced by the incorporation of low loading organophilic clay platelets. The surface morphological image for the neat PS and PS‐clay after a wear resistance test has also been compared and identified by the scanning electron microscopy (SEM). Furthermore, the effect of organoclay on three other different measurement types of mechanical properties for as‐prepared PCN materials, e.g., flexural tests, impact tests, and micron‐nano indenter tests were performed and compared. Generally, PCN materials exhibited an obvious enhancement of mechanical properties of neat polymer by an incorporated low loading of organophilic clay platelets into a polystyrene matrix used for the evaluation of mechanical properties as‐prepared samples. For example, mechanical strength (excepting flexural strength) almost remain same beyond 3 wt % clay loading in PS, whereas much detrimental effect being observed in the wear loss in case of PCNs with 5 wt % clay than 3 wt %. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effect of organic modifiers on dynamic and static nanomechanical properties and crystallinity of intercalated clay–polycaprolactam nanocomposites

Polymer clay nanocomposites (PCN) of Polyamide6 and sodium montmorillonite are prepared using different organic modifiers (12‐aminolauric acid, n‐dodecylamine, and 1,12‐diaminododecane) to study effect of organic modifiers on structure and nanomechanical properties of PCN. Using X‐ray diffraction and differential scanning calorimetry, crystalline nature of PCNs are evaluated. Nanoscale viscoelastic properties of PCNs are evaluated using nanodynamic mechanical analyzer (NanoDMA). Nanoscale elastic modulus and hardness of PCNs are evaluated using nanoindenter. PCNs show enhancement in elastic modulus, storage modulus, loss modulus, and loss factor by maximum amount of 62.88%, 56.38%, 145.74%, and 71.43%, respectively, and decrease in percentage crystallinity by 16.52% compared to pure polymer. This result indicates that organic modifiers have effect on crystallinity and nanomechanical properties of PCN. To evaluate effect of clay loading on nanomechanical properties of PCN, PCN containing 12‐aminolauric acid is synthesized with different weight percent (3, 6, and 9% of weight of polymer) of organically modified montmorillonite (OMMT), which shows that nanomechanical properties of PCN improves with increase in clay loading. Our study reveals that change in crystallinity of polymer in PCN may have role in the enhancement of nanomechanical properties of PCNs in comparison to pristine polymer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis and properties of poly(ethylene terephthalate)/clay nanocomposites by in situ polymerization

Poly(ethylene terephthalate) (PET)/clay nanocomposites (PCNs) with N‐methyl diethanol amine (MDEA)‐based organoclays are synthesized by using in situ polymerization. Four kinds of MDEA‐based materials are prepared and used as organifiers of pristine montmorillonite. The clay treated with the organifiers has a d‐spacing range that is about 14–21 Å. The PCNs with these organoclays are characterized by using wide‐angle X‐ray diffraction, scanning and transmission electron microscopy, atomic force microscopy, capillary rheometry, and tensile and barrier testing. The PCNs form an intercalated and delaminated structure. The well‐stacked nanoclays are broken down into small pieces in the PET matrix and the thickness of the clay bundle decreases to 20 nm. The melt viscosity and tensile strength of these PCNs increases with only 0.5 wt % clay. In oxygen barrier testing, the PCN with 1 wt % well‐dispersed organoclay shows a twofold higher barrier property than pure PET. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1262–1271, 2007     

Nanocomposites of poly(methyl methacrylate) and organically modified layered silicates by melt intercalation

Polymer‐layered silicate nanocomposites of poly(methyl methacrylate) (PMMA) and an organically modified silicate [tetraallkyl ditallow ammonium bentonite (B34)] system prepared via melt intercalation were studied. The saturation ratio of PMMA to B34 was 25:75 (w/w), as determined by dynamic mechanical thermal analysis, differential scanning calorimetry, and X‐ray diffraction. The interaction between PMMA and B34 was detected by Fourier transform infrared spectrometry, which showed two new absorption bands of PMMA/B34 hybrids in comparison with unannealed physical mixtures of PMMA and B34. The degradation temperature of the PMMA/B34 hybrids was 26°C higher than that of neat PMMA according to thermogravimetric analysis, the thermal stability of the hybrids having been enhanced. The glass‐transition temperature of excess PMMA remaining outside the clay galleries was about 12–19°C higher than that of neat PMMA. A structural model of the hybrid was also presented. It involves some PMMA chains diffusing into the gallery of B34 and expanding it by 6.8 Å and some penetrating and interacting with the organic chains of the modified cations. Some of the PMMA chains partly contained inside the clay layers were entangled with those remaining outside when PMMA in excess of the saturation ratio was used. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2101–2115, 2004     

Preparation and properties of (BATB–ODPA) polyimide–clay nanocomposite materials

A series of polymer–clay nanocomposite (PCN) materials consisting of 1,4‐bis(4‐aminophenoxy)‐2‐tert‐butylbenzene–4,4′‐oxydiphthalic anhydride (BATB–ODPA) polyimide (PI) and layered montmorillonite (MMT) clay were successfully prepared by an in situ polymerization reaction through thermal imidization up to 300°C. The synthesized PCN materials were subsequently characterized by Fourier‐Transform infrared (FTIR) spectroscopy, wide‐angle powder X‐ray diffraction (XRD) and transmission electron microscopy (TEM). The effects of material composition on thermal stability, mechanical strength, molecular permeability and optical clarity of bulk PI and PCN materials in the form of membranes were studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), molecular permeability analysis (GPA) and ultraviolet‐visible (UV/VIS) transmission spectra, respectively. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1072–1079, 2004     

Novel POBD‐modified organoclay and its polyimide nanocomposites for removal of the Co(II) ion

An organophilic clay has been obtained via cation exchange reaction between sodium montmorillonite and the hydrochloride salt of 2‐(5‐(3,5‐diaminophenyl)‐1,3,4‐oxadiazole‐2‐yl)pyridine, POBD. Thermogravimetric analysis (TGA) showed that thermal decomposition of the organophilic clay starts at about 350°C, which shows that it is quite thermally stable compared with conventional montmorillonite modified with aliphatic long chain surfactants. POBD‐modified organoclay almost quantitatively removed the Co(II) ion from aqueous solution at pH = 10.0 (Q_t = 3.00 mg g⁻¹, R = 98.2%). A series of polyimide/clay nanocomposite materials (PCNs) consisting of POBD and benzophenone‐3,3′,4,4′‐tetracarboxylic dianhydride, BTDA were also prepared by an in situ polymerization reaction via thermal imidization. POBD‐modified organoclay was used as a surfactant at different concentrations. Intercalation of polymer chains within the organoclay galleries was confirmed by WXRD. Both the glass transition temperature and thermal stability are increased with respect to pristine PI at low clay concentrations. At high clay loadings, the aggregation of organoclay particles results in a decrease in T_g and thermal stability. In the SEM images of PCN 1 and 3%, too many micro cracks are observed in the background, and a flower‐shape pattern spreads uniformly over the entire surface. The maximum Co(II) uptake capacity and efficiency were observed at pH 10.0 within a 40‐h period for both PI and PCN films. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Comparative studies of the properties of poly(methyl methacrylate)–clay nanocomposite materials prepared by in situ emulsion polymerization and solution dispersion

A series of polymer–clay nanocomposite (PCN) materials consisting of organic poly(methyl methacrylate) (PMMA) and inorganic montmorillonite (MMT) clay platelets were prepared successfully by the effective dispersion of nanolayers of the MMT clay in the PMMA framework through both in situ emulsion polymerization and solution dispersion. The as‐prepared PCN materials obtained with both approaches were subsequently characterized with wide‐angle powder X‐ray diffraction and transmission electron microscopy. For a comparison of the anticorrosion performance, a PCN material (e.g., 3 wt % clay loading) prepared by in situ emulsion polymerization, showing better dispersion of the clay platelets in the polymer matrix, exhibited better corrosion protection in the form of a coating on a cold‐rolled steel coupon than that prepared by solution dispersion, which showed a poor dispersion of the clay nanolayers according to a series of electrochemical corrosion measurements. Comparative studies of the optical clarity, molecular barrier properties, and thermal stability of samples prepared in both ways, as membranes and fine powders, were also performed with ultraviolet–visible transmission spectroscopy, molecular permeability analysis, thermogravimetric analysis, and differential scanning calorimetry. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1936–1946, 2004     

Preparation and properties of heterocyclically conjugated poly(3‐hexylthiophene)–clay nanocomposite materials

A series of heterocyclically conjugated polymer–clay nanocomposite (PCN) materials that consisted of organic poly(3‐hexylthiophene) (P3HT) and inorganic montmorillonite (MMT) clay platelets were prepared by in situ oxidative polymerization with FeCl₃ as an oxidant. The as‐synthesized PCN materials were characterized by Fourier transform infrared (FTIR) spectroscopy, wide‐angle powder X‐ray diffraction (WAXRD), and transmission electron microscopy (TEM). The effects of the material composition on the anticorrosion, gas barrier, thermal stability, flammability, mechanical strength, and electrical conductivity properties of the P3HT and PCN materials were studied by electrochemical corrosion measurements, gas‐permeability analysis (GPA), thermogrametric analysis (TGA), limiting oxygen index (LOI) measurements, dynamic mechanical analysis (DMA), and a four‐point probe technique, respectively. The molecular weights of extracted and bulk P3HT were determined by gel permeation chromatography (GPC) with THF as an eluant. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3438–3446, 2004     

Influence of processing conditions and physicochemical interactions on morphology and fracture behavior of a clay/thermoplastic/thermosetting ternary blend

This study provides information on the mechanical behavior of epoxy‐poly(methyl methacrylate) (PMMA)‐clay ternary composites, which have been prepared using the phase separation phenomenon of PMMA and the introduction of organophilic‐modified montmorillonites (MMTs), the continuous matrix being the epoxy network. Two dispersion processing methods are used: a melt processing without any solvent and an ultrasonic technique with solvent and a high‐speed stirrer. TEM analysis shows that phase separation between PMMA and the epoxy network was obtained in the shape of spherical nodules in the presence of the clay in both process methods used. Nanoclay particles were finely dispersed inside thermosetting matrix predominantly delaminated when ultrasonic blending was used; whereas micrometer‐sized aggregates were formed when melt blending was used. The mechanical behavior of the ternary nanocomposites was characterized using three‐point bending test, dynamic mechanical analysis (DMA), and linear elastic fracture mechanics. The corresponding fracture surfaces were examined by scanning electron microscopy to identify the relevant fracture mechanisms involved. It was evidenced that the better dispersion does not give the highest toughness because ternary nanocomposites obtained by melt blending present the highest fracture parameters (K_Ic). Some remaining disordered clay tactoids seem necessary to promote some specific toughening mechanisms. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Enhanced corrosion prevention effect of polysulfone–clay nanocomposite materials prepared by solution dispersion

A series of polymer–clay nanocomposite (PCN) materials containing polysulfone (PSF) and layered MMT clay were successfully prepared by effectively dispersing inorganic nanolayers of MMT clay in an organic PSF matrix via a solution dispersion technique. The synthesized PCN materials were subsequently investigated with a series of characterization techniques, including Fourier transform infrared (FTIR) spectroscopy, wide‐angle powder X‐ray diffraction (XRD) and transmission electron microscopy (TEM). The prepared PCN coatings with low clay loading (1 wt %) on cold‐rolled steel (CRS) were found to be superior in corrosion prevention to those of bulk PSF, based on a series of electrochemical measurements of corrosion potential, polarization resistance, corrosion current and electrochemical impedance spectroscopy (EIS) in a 5 wt % aqueous NaCl electrolyte. The effects of material composition on the molecular barrier, mechanical strength and optical clarity of PSF and PCN materials, in the form of membranes, was also studied by molecular permeability analysis (GPA), dynamic mechanical analysis (DMA) and UV‐Visible transmission spectra, respectively. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 631–637, 2004     

Enhanced corrosion protection coatings prepared from soluble electronically conductive polypyrrole‐clay nanocomposite materials

A series of electronically conductive nanocomposite materials that consisted of soluble polypyrrole (PPY) and layered montmorillonite (MMT) clay platelets were prepared by effectively dispersing the inorganic nanolayers of MMT clay in organic PPY matrix via an in situ oxidative polymerization with dodecylbenzene sulfonic acid (DBSA) as dopant. Organic pyrrole monomers were first intercalated into the interlayer regions of organophilic clay hosts and followed by a one‐step oxidative polymerization. The as‐synthesized electronically conductive polypyrrole–clay nanocomposite (PCN) materials were then characterized by Fourier transformation infrared (FTIR) spectroscopy, wide‐angle powder X‐ray diffraction (XRD), and transmission electron microscopy (TEM). PCNs in the form of coatings with low clay loading (e.g., 1.0 wt %) on cold‐rolled steel (CRS) were found to exhibit much better in corrosion protection over those of pristine PPY based on a series of electrochemical measurements including corrosion potential, polarization resistance, and corrosion current in 5 wt % aqueous NaCl electrolyte. Effects of the material composition on the thermal stability, optical properties, and electrical conductivity of pristine PPY along with PCN materials, in the form of fine powder, powder‐pressed pellet, and solution, were also studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), UV‐visible absorption spectra, and four‐point probe technique, respectively. The viscosity of PPY existed in PCN materials and pristine PPY were determined by viscometric analysis with m‐cresol as solvent. The heterogeneous nucleating effect of MMT clay platelets in PPY matrix was studied by wide‐angle powder XRD. The corresponding morphological images of the nucleating behavior of clay platelets in PPY matrix were investigated by scanning electron microscopy (SEM). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 3264–3272, 2003     

Effect of organoclay on the thermal stability,mechanical strength,and surface wettability of injection‐molded ABS–clay nanocomposite materials prepared by melt intercalation

In this article, a series of polymer–clay nanocomposite (PCN) materials consisted of commercial thermoplastic ABS matrix and dispersing inorganic organoclay platelets were successfully prepared by melt intercalation through the twin‐roller mixer. The as‐prepared materials in the form of pellet were then shaped by injection‐molding machine and the as‐molded specimens were subsequently examined by chemical characterizations, through Fourier transformation infrared (FTIR) spectroscopy, powder X‐ray diffraction (XRD), and transmission electron microscopy (TEM). Effect of the organoclay on thermal stability, mechanical strength, and surface wettability of PCN materials, in both the form of standard dumbbell shape and pellet, was studied using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), tensile test, hardness test, and contact‐angle measurements, respectively. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99; 1576–1582, 2006     

The role of interfacial interactions on the crystallinity and nanomechanical properties of clay–polymer nanocomposites: A molecular dynamics study

Polymer clay nanocomposites (PCN) show enhanced mechanical, thermal, liquid or gas barrier properties in comparison to pure polymer. However, the mechanisms for enhancement of these physical properties of PCN are not well understood. This knowledge is important for tailoring the properties of PCN to desired specifications. Our earlier study showed that organic modifiers have significant influence on the crystallinity and nanomechanical properties of PCN. For quantitative evaluation of the influence of organic modifiers on the crystallinity and nanomechanical properties of PCN, molecular models of three intercalated PCNs containing same polymer and clay but with three different organic modifiers are constructed in this work. Using molecular dynamics simulations, the interaction energies among the different constituents of PCNs are evaluated. This study reveals that the interactions between polymer, organic modifiers, and intercalated clay are critical factors in controlling the crystallinity and enhancement of nanomechanical properties of PCN. We have described the possible mechanisms leading to change in crystallinity and nanomechanical properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effect of clay with different cation exchange capacity on the morphology and properties of poly(methyl methacrylate)/clay nanocomposites

PMMA/clay nanocomposites were successfully prepared by in situ free‐radical polymerization with the organic modified MMT‐clay using methyl methacrylate monomer and benzoyl peroxide initiator. Two clays with different cation exchange capacity have been used to prepare and compare the several properties. The clays have been modified using Amphoterge K2 by ion exchange reaction to increase the compatibility between the clay and polymer matrices. The modified clays have been characterized by wide‐angle X‐ray diffraction pattern, Fourier transform infrared spectroscopy, and thermogravimetric analysis (TGA). The powdered X‐ray diffraction and transmission electron microscopy techniques were employed to study the morphology of the PMMA/clay nanocomposites which indicate that the modified clays are dispersed in PMMA matrix to form both exfoliated and intercalated PMMA/modified clay nanocomposites. The thermomechanical properties were examined by TGA, differential scanning calorimetry, and dynamic mechanical analysis. Gas permeability analyzer shows the excellent gas barrier property of the nanocomposites, which is in good agreement with the morphology. The optical property was measured by UV–vis spectroscopy which shows that these materials have good optical clarity and UV resistance. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Thermal and mechanical properties of melt processed intercalated poly(methyl methacrylate)–organoclay nanocomposites over a wide range of filler loading

BACKGROUND: Poly(methyl methacrylate) (PMMA)–organoclay nanocomposites with octadecylammonium ion‐modified montmorillonite, prepared via melt processing, over a wide range of filler loading (2–16 wt%) were investigated in detail. These hybrids were characterized for their dispersion structure, and thermal and mechanical properties, such as tensile modulus (E), break stress (σ_brk), percent break strain (ε_brk) and ductility (J), using wide‐angle X‐ray diffraction, transmission electron microscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and tensile and impact tests. RESULTS: Intercalated nanocomposites were formed even in the presence of 16 wt% clay (high loading) in PMMA matrix. PMMA intercalated into the galleries of the organically modified clay, with a change in d‐spacing in the range 11–16 Å. TGA results showed improved thermal stability of the nanocomposites. The glass transition temperature (T_g) of the nanocomposites, from DSC measurements, was 2–3 °C higher than that of PMMA. The ultimate tensile strength and impact strength decreased with increasing clay fraction. Tensile modulus for the nanocomposites increased by a significant amount (113%) at the highest level of clay fraction (16 wt%) studied. CONCLUSION: We show for the first time the formation of intercalated PMMA nanocomposites with alkylammonium‐modified clays at high clay loadings (>15 wt%). Tensile modulus increases linearly with clay fraction, and the enhancement in modulus is significant. A linear correlation between tensile strength and strain‐at‐break is shown. Thermal properties are not affected appreciably. Organoclay can be dispersed well even at high clay fractions to form nanocomposites with superior bulk properties of practical interest. Copyright © 2007 Society of Chemical Industry     

Use of a new natural clay to produce poly(methyl methacrylate)‐based nanocomposites

Nanocomposites of poly(methyl methacrylate) (PMMA) filled with 3 wt% of modified natural Algerian clay (AC; montmorillonite type) were prepared by either in situ polymerization of methyl methacrylate initiated by 2,2′‐azobisisobutyronitrile or a melt‐mixing process with preformed PMMA via twin‐screw extrusion. The organo‐modification of the AC montmorillonite was achieved by ion exchange of Na⁺ with octadecyldimethylhydroxyethylammonium bromide. Up to now, this AC montmorillonite has found applications only in the petroleum industry as a rheological additive for drilling muds and in water purification processes; its use as reinforcement in polymer matrices has not been reported yet. The modified clay was characterized using X‐ray diffraction (XRD), which showed an important shift of the interlayer spacing after organo‐modification. The degree of dispersion of the clay in the polymer matrix and the resulting morphology of nanocomposites were evaluated using XRD and transmission electron microscopy. The resulting intercalated PMMA nanocomposites were analysed using thermogravimetric analysis and differential scanning calorimetry. The glass transition temperature of the nanocomposites was not significantly influenced by the presence of the modified clay while the thermal stability was considerably improved compared to unfilled PMMA. This Algerian natural montmorillonite can serve as reinforcing nanofiller for polymer matrices and is of real interest for the fabrication of nanocomposite materials with improved properties. Copyright © 2009 Society of Chemical Industry     

Effect of clay platelet dispersion as affected by the manufacturing techniques on thermal and mechanical properties of PMMA‐clay nanocomposites

In this work, the properties of Poly(methyl methacrylate) (PMMA)‐clay nanocomposites prepared by three different manufacturing techniques viz., solution mixing, melt mixing, and in‐situ bulk polymerization in presence of clay were studied. Morphological analysis revealed that the extent of intercalation and dispersion of the nanoclay were relatively higher in the in‐situ polymerized nanocomposites than those of solution and melt blended nanocomposites. Differential Scanning Calorimetric study indicated maximum increment in T_g of the PMMA in the in‐situ polymerized PMMA‐clay nanocomposites. Thermo gravimetric analysis showed improved thermal stability of PMMA in all the nanocomposites and the maximum improvement was for in‐situ polymerized nanocomposites. The storage moduli of all the nanocomposites were higher than the pure PMMA. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009