Epoxy/epoxies nanocomposites

Hussain, F., Chan, J., and Hojjati, M. 2007. Epoxy-silicate nanocomposites Cure monitoring and Characterization. Material Science and Engineering A 445-446 467-476. 

Literature search shows that epoxy-based nanocomposites have been prepared by many researchers [34-38]. Becker et al. have prepared nanocomposites based on various high-functionahty epoxies. The mechanical, thermal, and morphological properties were also investigated thoroughly [39 3]. The cure characteristics, effects of various compatibilizers, thermodynamic properties, and preparation methods [16,17,44 9] have also been reported. ENR contains a reactive epoxy group. ENR-organoclay nanocomposites were investigated by Teh et al. [50-52]. 

Epoxy-clay nanocomposites from epoxide precursors have been investigated by research groups at Michigan State University [34-40], Cornell University [41], and Case Western Reserve University [42,43]. In general, the synthesis is similar to that of Nylon-6 and PS... 

FIG. 10 Compressive (a) yield strength and (b) moduli for the pristine epoxy polymer and the exfoliated epoxy-clay nanocomposites prepared from three different kinds of organomontmorillonites. (From Ref. 40.)... 

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. 

Epoxy nanocomposites, 10 350, 434 Epoxy novolac resins, 10 367-370, 383, 450 multifunctional, 10 452 Epoxy novolacs, 17 839 1,2-Epoxypentane, butyraldehyde derivative, 4 462... 

T. Lan, T.J. Pinnavaia, Mechanism of clay tactoid exfoliation in epoxy-clay nanocomposites, Chem. Mater., vol. 7, pp. 2144-2150,1995. 

X. Kornmann, H. Lindberg, L. A. Berglund, Synthesis of epoxy-day nanocomposites. Influence of the nature of the curing agent on structure, Polymer, vol. 42, pp. 4493-4499,2001. 

Fig. 29 TEM micrographs of LDH/epoxy nanocomposites with various LDH contents a 7 wt %, b 5 wt %, and c 3 wt %. The bar length is 50 nm (top) and the process of formation of LDH/epoxy nanocomposites is also shown bottom). (Reprinted from [115] with permission from Elsevier)...

B. Schartel, U. Knoll, A. Hartwig, and D. Ptttz, Phosphonium-modified layered silicate epoxy resins nanocomposites and their combinations with ATH and organo-phosphorus fire retardants, Polym. Adv. Technol., 2006, 17 281-293. 

Figure 2.10. (a) Flexural strength and (b) modulus of epoxy nanocomposites as a function of increasing the filler fraction. Reproduced from reference 48 with permission from Elsevier. 

In the epoxy nanocomposites containing untreated as well as maleic anhydride grafted nanotubes (51), the tensile strength was observed to increase by 50% at 1 wt% of the modified nanotubes, whereas the untreated nanotubes led to only a slight increase in the tensile strength which subsequently decreased on further addition of these pristine nanotubes. The tensile modulus of the nanocomposites was observed... 

Tseng et al. (51) reported the epoxy nanocomposites in which the nanotubes were functionalized by maleic anhydride by using plasma treatment. The thermal decomposition temperature was reported to increase with increasing the extent of the nanotubes in the composites as shown in Figure 2.16a. Untreated nanotubes were also used to reinforce the polymer and the increase in the decomposition temperature was also observed in this system as a function of filler content, but the enhancement was more significant using the functionalized nanotubes. This was attributed to... 

Figure 2.16. Enhancement of (a) decomposition temperature as well as (b) glass transition temperature as a function of filler content in epoxy nanocomposites. Reproduced from reference 51 with permission from American Chemical Society.

In one further work on epoxy-POSS, comparative studies were conducted on epoxy/ladderlike polyphenylsilsesquioxane (PPSQ) blends and the associated nanocomposites [2]. The work revealed that, although a decrease in the flexural strength and modulus of epoxy/POSS nanocomposites in comparison to the neat epoxy resin was observed, only flexural strength deteriorated in the epoxy/PPSQ blends compared to the neat epoxy resin. Flexural modulus of epoxy/PPSQ blends was reported to be much higher than that of the epoxy resin and also increased with an increase in POSS content. It was... 

Messersmith, P.B. Giannelis, E.P. Synthesis and characterization of layered silicate-epoxy nanocomposites. Chem. Mater. 1994, 6, 1719-1725. 

Figure 15.7. Tensile strength of epoxy/montmorillonite nanocomposite vs. flller concentration. [Adapted, by permission, from Lan T, Pinnavaia T J, Chem. of Mat., 6, No. 12, 1994, 2216-9.]...

Epoxy-nanocomposite systems are relatively novel systems examined first by Pinavaia and Gianellis (Wang and Pinnavaia, 1994, Messersmith and Giannelis, 1994). A recent review of epoxy nanocomposites is provided by Becker and Simon (2005). In terms of che-morheology of epoxy-nanocomposite systems, there are relatively few papers, however. 

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. 

Suguna Lakshmi, M., Narmadha, B. Reddy, B. S. R. (2008). Enhanced thermal stability and structural characteristics of different MMT-Clay/epoxy-nanocomposite materials. Polymer Degradation and Stability, Vol. 93, No. 1, pp 201-213... 

Ha, SR, Ryu, SH, Park, S J, Rhee, KY. 2007. Effect of clay surface modification and concentration on the tensile performance of clay/epoxy nanocomposites. Mater Sci Eng A-Struct 44S 264—268. 

---