Vinyl ester nanocomposites resins

Improved versions of the high performance resin systems continue to be developed (245,246). Toughening of epoxies and epoxy vinyl esters has emerged as an area for investigation (247). Lower styrene content vinyl esters have been developed to reduce worker exposure. Performance enhancements with epoxy and vinyl ester nanocomposites have been reported in the literature, but commercialization has not been yet realized. 

FIGURE 9.31 Glass transition temperature versus clay content for an intercalated vinyl ester nanocomposite (Cloisite lOA), a microcomposite (vinyl monomCT clay), and neat resin. (From Ref. 95, copyright 2002, John Wiley Sons, Inc., with pamission.)... 

FIGURE 9.32 Comparison of the heat release rate plot for a standard brominated vinyl ester resin and vinyl ester nanocomposites (6 wt% Cloisite 15A) additivated with 15 wt% RDP or 30 wt% TCP. (From Ref. 94, copyright 2005, Elsevier, with permission.). 

Gilman, J.W., Kashiwagi, T., Nyden, M., Brown, J.E.T., Jackson, C.L., Lomakin, S., Giannelis, E.P., and Manias, E., Flammability studies of polymer layered silicate nanocomposites Polyolefin, epoxy, and vinyl ester resins, in Chemistry cmd Technology of Polymer Additives, Al-Malaika, S., Golovoy, A., and Wilkie, C.A., (Eds.), Blackwell Science, Oxford, U.K., 1999, Chapter 14, pp. 249-265. 

Granular polymer nanocomposites have also been investigated for possible GMR applications [43,96]. Conductive iron nanoparticle-reinforced vinyl ester resin nanocomposites are observed to possess MRs of only 0.9%, which increase to 1.7% after... 

Figure 12.17 (Reprinted with permission from Journal of Applied Physics, Magnetic and magnetoresistance behaviors of particulate iron/vinyl ester resin nanocomposites by Z. Guo, H. T. Hahn, H. Lin etal., J. Appl.Phys., 104, 014314. Copyright (2008) American Institute of Physics)...

As most work reported to date on thermosetting layered silicate nanocomposites involves epoxy resins, this review will focus on this class of thermosetting materials. However, some work pubUshed on other thermosets such as vinyl ester resins and imsaturated polyesters will be included where appropriate. 

Table 2 Cone calorimeter data for modified bisphenol A vinyl ester (Mod-Bis-A Vinyl Ester), bisphenol A novolac vinyl ester (Bis-/Novolac Vinyl Ester) and methylenedianiline and benzyldimaine (BDMA) cured epoxy resins and their intercalated nanocomposites ( ) containing 6% dimethyl dioctadecylammonium-exchanged montmorillonite. Heat flux = 35 kW/m, HRR = heat release rate, MLR = mass loss rate. He = heat of combustion, SEA = specific extinction area [121]...

Four types of FR additives were used in this study, namely siloxane powder, char forming additive, layered silicate nanocomposites and ATFi. Fieat release of these (Figure 2.3) compared with those of a virgin additive-free brominated vinyl ester resin (Figure 2.2). Table 2.4 presents the results of F3RR and smoke generation. 

Guo, Z., Liang, X., Pereira, T., Scaffaro, R., Hahn, H.T. CuO nanoparticle filled vinyl-ester resin nanocomposites fabrication, characterization and property analysis. Compos. Sci. Technol. 67, 2036-2044 (2007)... 

PMMA/y-Fe203 composites by in-situ polymerization. The presence of OA on the metal oxide surface increased the compatibility of the metal oxide NPs with the polymeric matrix and yielded bulk homogeneous and highly transparent PMMA/y-Fe203 composites [169]. Magnetic vinyl ester resin nanocomposites... 

J. W. Gilman, T. Kashiwagi, M. Nyden, J. E. T. Brown, C. L. Jackson, S. Lomakin, E. P. Giannelis, and E. Manias, Elammability studies of polymer layered silicate nanocomposites Polyolefin, epoxy and vinyl ester resins. In Chemistry and Technology of Polymer Additives, ed. S. Al-Malaika, A. Golovoy, and C. A. Wilkie (Malden Black-well Science, 1999), pp. 249-65. 

The mechanical properties and water diffusivity of vinyl ester/clay nanocomposites have been investigated by Shah et al. A vinyl ester resin (bisphenol A... 

Gilman et al. found similar reductions in the PHRR of clay nanocomposites. They prepared 6 wt% intercalated nanocomposites with Cloisite 15A dispersed in a nitrile rubber-modified bisphenol A epoxy-based vinyl ester (mod-bis-A) or a combination of bisphenol A and novolac epoxy-based vinyl ester (bis-A/novolac). The PHRR was reduced by 25 and 39% for mod-bis-A and bis-A/novolac, respectively. The clay promoted charring in fact, no residue was obtained for the neat resins, while in the nanocomposites the residue yields were 8 wt% (mod-bis-A) or 9 wt% (bis-A/novolac). The heat of combustion, specific extinction area, and carbon monoxide yields were unchanged. 

A study by Shah et on die moisture diffusion of a (non-epoxy) vinyl ester resin-based layered silicate nanocomposite also reported a deereased moisture diffiisivity of the nanocomposite, ascribed to the restricted mobility of the polymer chains tethered to the clay particles. A reverse effect, however, could be observed for the equilibrium water uptake of one of the two fillers investigated. The equilibrium water uptake of a vinyl-monomer containing clay nanocomposites increased from 0.012% (neat resin) to 0.021 (5% clay). The water uptake of the other, an alkyl ammonium-treated montmorillonite clay, Cloisite lOA, remained relatively unaffected by the filler addition. The increase of the first nanocomposites system was related to the strong, hydrophilic behaviour of the clay, which remains to some degree in the surface treated state. 

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