Synthesis of epoxy–clay nanocomposites: influence of the nature of the clay on structure

Kornmann, Xavier; Lindberg, Henrik; Berglund, Lars A.

doi:10.1016/s0032-3861(00)00346-3

Cited by 609 publications

(467 citation statements)

References 24 publications

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“…So far, the results from XRD, SEM, and TEM combine to indicate that with high speed and temperature assistance, one can obtain a fine dispersion at the micro-scale, good distribution of clay, and good intercalation/exfoliation of clay in the epoxy system. Kornmann et al [3,4] also obtained an intercalated/ exfoliated structure for epoxy nanocomposites, but the clay particles were not uniform and homogeneously distributed in the matrix, and a substantial number of large clay aggregates remained. Good intercalation and good dispersion have also been obtained by using a three-roll mill to disperse the clay nanoparticles, as reported by Yasmin et al [6].…”

Section: Resultsmentioning

confidence: 99%

“…Dispersion process parameters mainly include premixing temperature, mixing speed and time, power of ultrasonic tooling, shearing forces, etc. Direct mixing of organoclay and epoxy with mechanical mixing and sonication is widely used to disperse nanoclay in epoxy [1][2][3][4][5]. However, it is not enough to produce a high degree of dispersion.…”

Section: Introductionmentioning

confidence: 99%

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Preparation and properties of epoxy nanocomposites. I. The effect of premixing on dispersion of organoclay

Ngo¹,

Ton‐That

Hoa³

et al. 2009

Polymer Engineering & Sci

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The objective of this work was to systematically study the effect of the conditions of shear and temperature used to premix nanoclay with epoxy resin on the dispersion and intercalation/exfoliation of the nanoclay in the resulting epoxy nanocomposites. The different mixing approaches used were hand stirring, conventional mechanical stirring, a high-speed homogenizer, and a microfluidizer. The quality of dispersion and intercalation/exfoliation of the organoclay in the epoxy resin was analyzed after premixing (before adding hardener) by means of X-ray diffraction (XRD) and rheological measurements. Nanocomposites obtained after adding hardener and curing were characterized by means of XRD, field emission gun scanning electron microscopy, transmission electron microscopy, and image analysis. Both the premixing and curing steps were found to play a determining role in the dispersion and intercalation/exfoliation of organoclay. Increased intercalation and exfoliation can take place during curing, with the extent depending on the curing rate. Although full exfoliation of clay cannot be achieved at the premixing stage, this step appears to be very important in controlling the micro-dispersion and thus affecting the further intercalation and exfoliation that take place during the curing step.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Preparation and properties of epoxy nanocomposites. I. The effect of premixing on dispersion of organoclay

Ngo¹,

Ton‐That

Hoa³

et al. 2009

Polymer Engineering & Sci

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“…The incorporation of organophilic nanoclay into both unmodified epoxy and CMDI-toughened epoxy systems reduces the values of T g . The decrease in the values of T g is due to the plasticization of organoclay-modified epoxy systems during swelling period by cetyltrimethylammonium ions [29][30][31][32].…”

Section: Thermal Propertiesmentioning

confidence: 99%

“…The peaks of hybrid nanocomposites containing 1, 3, and 5 wt% of organoclay were slightly lower (1648C, 1608C, and 1558C, respectively) than that of unmodified epoxy (Table 1), which was in good agreement with those obtained by means of DSC. Because the peak height is associated with molecular mobility, it is observed that the intercalation of the polymer molecules between the clay layers has greatly reduced their molecular mobility [29,30] and decreased the intensity of tan d. Figure 6 shows the plots of storage modulus as functions of temperature for the neat epoxy and the resulting nanocomposites. The clay addition has a considerable effect in the stiffness behavior of the nanocomposites which affects the dynamic mechanical properties of the nanocomposites.…”

Section: Mechanical Propertiesmentioning

confidence: 99%

Organoclay‐filled caprolactam‐blocked methylenediphenyl diisocyanate‐toughened epoxy interpenetrating network matrices

Premkumar

Chozhan

Alagar

2009

Polymer Engineering & Sci

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An interpenetrating networks of varying weight percentages (5, 10, and 15%) of caprolactam-blocked methylenediphenyl diisocyanate(CMDI)-toughened epoxy matrices were developed and characterized. The toughened epoxy system was further modified with 1, 3, and 5% (by wt) of organophilic montmorillonite (MMT) clay. Organoclay-filled hybrid CMDI-epoxy matrices, developed in the form of castings, were characterized for their thermomechanical properties. The data obtained from differential scanning calorimetry and dynamic mechanical analysis showed that there was a significant loss in the values of glass transition temperatures (T g ) of organoclay-filled hybrid epoxy systems when compared with that of neat epoxy resin, whereas increasing trend in thermal stability was observed. The values obtained from mechanical studies indicated that the CMDI-toughened epoxy and organoclay-filled CMDI-epoxy systems were improved the mechanical properties according to its percentage concentration. From X-ray diffraction analysis, it was observed that the presence of d 001 reflections of the organophilic MMT clay in the CMDI-toughened epoxy systems indicated the development of intercalated clay structure which in turn confirmed the formation of intercalated nanocomposites. Homogeneous surface morphologies of CMDI-toughened epoxy and organoclay-filled CMDItoughened epoxy systems were ascertained from scanning electron microscope. POLYM. ENG. SCI., 49:747-755, 2009. ª

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“…The ability to determine the size and shape of clay platelets accurately is of fundamental importance in understanding the structure of polyelectrolyte/clay multilayer films (Kleinfeld andFerguson 1994, Rouse et al 2000), the behavior of clay suspensions (Avery and Ramsay 1986, Bonn et al 1999, Kroon et al 1998, Mourchid et al 1998, Nicolai and Cocard 2000, Rosta and von Gunten 1990 and clay/polymer composites (Balazs et al 1999, Gilman 1999, Kawasumi et al 1997, Kornmann et al 2001, Sonobe et al 1999, Tyan et al 1999, Vaia et al 19961999). Although scattering techniques (e.g., visible light, x-ray, neutron) have proven useful for characterizing clay suspensions, the ability to differentiate between scattering from single particles and aggregates has proven difficult (Nicolai andCocard 2000, Rosta andvon Guten 1990).…”

Section: Introductionmentioning

confidence: 99%

A method for imaging single clay platelets by scanning electron microscopy

2004

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Summary:A method for preparing and observing clay platelets for size and shape analysis using scanning electron microscopy (SEM) was developed. Samples of the clay platelets were prepared by polyelectrolyte-assisted adsorption onto a pyrolytic graphite surface. The use of graphite as a substrate was advantageous because of the low number of secondary electrons emitted from it during imaging by SEM. The resulting low background noise allowed the emission from the ~1 nm thick clay sheets to be clearly visualized. Images of centrifuged montmorillonite showed large exfoliated platelets with lateral dimensions between 200 and 600 nm. In contrast, uncentrifuged montmorillonite appeared to contain a large amount of unexfoliated clusters. Although it was not possible to obtain high-quality images of the smaller sheets of Laponite RD, the images of this material did contain size features comparable to the ~30 nm 2 size reported previously using light scattering, as well as transmission electron and atomic force microscopies.

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Synthesis of epoxy–clay nanocomposites: influence of the nature of the clay on structure

Cited by 609 publications

References 24 publications

Preparation and properties of epoxy nanocomposites. I. The effect of premixing on dispersion of organoclay

Preparation and properties of epoxy nanocomposites. I. The effect of premixing on dispersion of organoclay

Organoclay‐filled caprolactam‐blocked methylenediphenyl diisocyanate‐toughened epoxy interpenetrating network matrices

A method for imaging single clay platelets by scanning electron microscopy

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