Sepiolite addition, effect

Substitution and variations in the tetrahedral sites change the manner of side linkages for the ribbons, effecting the octahedral cation and water associations. In addition, different ribbon widths can lead to different numbers of octahedral cations. Variation in the width of chains and substitution of cations and water are easily accomplished, which means that accurate and consistent chemical and crystal structural data on these minerals are difficult or, at best, approximate. However, the minerals do form fibers with a consistent fiber axis repeat of about 0.512 nm (Preisinger, 1959 Rautureau et al., 1972). Sepiolite and palygorskite represent the widest possible structural and chemical diversity among fibrous silicate minerals. 

Figure 5. The effects of vanadium on a cracking catalyst activity before and after addition of a metal scavenger (Spanish sepiolite).

The effect on the modulus and yield stress of the scCCh processed PP nanocomposites was studied for the addition of MWNTs and sepiolite clays (Ma et al., 2007 and 2010). The results were comp>ared with traditional melt compounded nanocomposites. 

Figure 12.22b suggested a synergistic effect of clay combination. Addition of 5wt% MMT/sepiolite mixture to the PP -i-10% MH significantly decreased the maximum HRR (from 471 to 246kW/m2) and increased the time of ignition in comparison with formulations with 5% MMT only. 

Acosta, J. L., Morales, E., Ojeda, M. C., and Linares, A. 1986. Effect of addition of sepiolite on the mechanical properties of glass-fiber reinforced polypropylene. Angewandte Makromolekulare Chemie 138 103-110. 

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