Nanocomposite microcellular cell

Figure 9.7. TEM Images of (a) Solid PLA-MWCNT Nanocomposite at 500 nm (Inset-a magnified view of agglomerated MWCNTs at 100 nm) (b) Microcellular PLA-MWCNT Nanocomposite at 500 nm (arrow indicates micro cell formed during microcellular injection-molding) (c) Solid PLA-MWCNT Nanocomposite at 100 nm and (d) Microcellular PLA-MWCNT Nanocomposite at 100 nm. Reprinted with permission from S. Pilla et al.. International Polymer Processing, XXII, p. 418,2007, 2007, Polymer Processing Society.

M. Shimbo, D. R Baldwin and N. P. Suh, The viscoelastic behavior of microcellular plastics with varying cell size. Polymer Engineering Science, 35, 1387-1393 (1995). M. Yuan, L. S. Tumg, S. Gong, D. Caulfield, C. Hunt and R. Spindler, Study of injection molded microcellular polyamide-6 nanocomposites, Polymer Engineering Science, 44, 673-686 (2004). 

Comparison between the two nanocomposites revealed that the number of the stacked individual silicate layers D 001) for PLA/SBE nanocomposites was much lower than for PLA/ODA nanocomposites, suggesting that intercalated silicate layers were more homogeneously and finely dispersed in the case of PLA/SBE than in PLA/ODA (Table 17.3). The nature of the dispersion also plays a vital role in controlling the size of the cell during foaming since PLA/SBE5 nanocomposites had nanocellular structure as opposed to the microcellular structure of the PLA/ODA5 nanocomposites. 

Low-density microcellular foams were achieved by using a mixture of CO2 and N2. Foams of PCL and PCL containing 2% of nanoclay, prepared with CO2/N2 mixture are shown in Figure 8. Even though the final density of these foams is almost the same, the cellular structure of the nanocomposite foam is characterized by higher number of cells of smaller size. 

Zhai W, Yu J, Wu L, Ma W, He J. Heterogeneous nucleation uniformizing cell size distribution in microcellular nanocomposites foams. Polymer 2006 47 7580-9. 

Carbon nanofiber (CNF) is one type of cylindrical nanoparticle. PS/CNF nanocomposite is studied for batch foam. With the addition of CNFs, microcellular foams with uniform cell size distributions were obtained. A single screw extruder was used to prqrare PS/CNF extrusion foam. Microcellular foam with cell size of 4.1 microns is made with 5% weight fi action of CNF in PS. 

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