Clay-reinforced epoxy nanocomposites

T.J. Pinnavaia, T. Lan, Z. Wang, H. Shi and P.D. Kaviratna, Clay-reinforced epoxy nanocomposites Synthesis, properties, and mechanism of formation. In G.-M. Chow and K.E. Gonsalves (Eds.), Nanotechnology Molecularly Designed Mlaterials, American Chemical Society, Washington, 1996, Vol. 622, p. 250. 

Lan, T. and Pinnavaia, T. J. 1994. Clay-reinforced epoxy nanocomposites. Chemistry cf Materials 6 2216-2219. 

Pinnavaia, T. J. Lan, T. Wang, Z. Shi, H. Kaviratna, P. D., Clay-Reinforced Epoxy Nanocomposites Synthesis, Properties, and Mechanism of Formation. 

Lan Tie, and Pinnavaia J. Thomas. Clay-reinforced epoxy nanocomposites. J. Chem. Mater. 6 no. 12 (1994) 2216-2219. 

Ratna D, Manoj N R, Varley R, Singh Raman R K and Simon G P (2003) Clay-reinforced epoxy nanocomposites, Polym Intern 52 1403-1407. 

Lan T, WangZ, Shi H, PinnavaiaTJ (1995) Clay-epoxy nanocomposites relationships between reinforcement properties and the extend of clay layer exfoliation, in Polimeric Materials - Science and Engineering. Proceedings of the ACS Division of... 

The water absorption behavior of the clay-epoxy nanocomposites in terms of maximum water uptake and diffusion coefficient are given in Table 9.18 [47]. The presence of nanoparticle as reinforcement reduces the water absorption of the composite system. The maximum water uptake of epoxy decreases gradually with the increase in clay content. The maximum water absorption decreases by 14.1,17.9 and 24.8% after the incorporation of 1, 3 and 5 wt% nano-clay, respectively, compared with neat epoxy. The presence of high aspect ratio nanofillers can create a tortuous pathway for water molecules to diffuse and enhances the resistance to water absorption. The diffusivity also decreases in the same manner and a significant reduction in diffusivity is obtained for the composites containing 5 wt% clay [112]. 

Biobased epoxy nanocomposites can be reinforced with organo montmorillonite clay and carbon fibers obtained from poly(acryl-onitrile) (45). To get the organically modified clay into the glassy biobased epoxy networks, a sonication technique was used. In this way, clay nanoplatelets were obtained that were homogeneously dispersed and completely exfoliated in the matrix. 

The most widely used reinforcements in nanocomposites are carbon nanotubes, layered clay, and nanoparticles. The most widely used polymer matrices are polyamides, nonpolar polymers, polyesters, epoxies, and polyurethane. However, this chapter will focus on nanocomposites which are made from both biodegradable fiber/fillers and biodegradable matrices, since only these composites truly justify the definition of eco-friendly and green nanocomposites. 

Bozkurt, E., Kaya, E., Tanoglu, M., 2007. Mechanical and thermal behavior of non-crimp glass fiber reinforced layered clay/epoxy nanocomposites. Compos. Sci. Technol. 67 (15-16), 3394-3403. 

The effect of polymer-filler interaction on solvent swelling and dynamic mechanical properties of the sol-gel-derived acrylic rubber (ACM)/silica, epoxi-dized natural rubber (ENR)/silica, and polyvinyl alcohol (PVA)/silica hybrid nanocomposites was described by Bandyopadhyay et al. [27]. Theoretical delineation of the reinforcing mechanism of polymer-layered silicate nanocomposites has been attempted by some authors while studying the micromechanics of the intercalated or exfoliated PNCs [28-31]. Wu et al. [32] verified the modulus reinforcement of rubber/clay nanocomposites using composite theories based on Guth, Halpin-Tsai, and the modified Halpin-Tsai equations. On introduction of a modulus reduction factor (MRF) for the platelet-like fillers, the predicted moduli were found to be closer to the experimental measurements. 

Reinforcement of the epoxy-clay nanocomposites was also dependent on the clay loading as shown in Fig. 29. Thus for epoxy CH3(CH2)17NH3+-MMT nanocomposite system, the tensile strength and modulus increased nearly linearly with clay loading. More than a tenfold increase in strength and modulus could be realized by the addition of ca. 15 wt % of the exfoliated organoclay. 

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