Nanoclay loading effect

Fig. 4 Effect of nanoclay loading on neat SEBS a Lorentz -corrected SAXS profiles (vertically shifted for better clarity) showing effect of nanoclay arrows indicate peak positions, b Lengths corresponding to first- and second- order scattering vector positions along with the 2D SAXS patterns for each sample of clay-loaded nanocomposites...

In the literature, there are several reports that examine the role of conventional fillers like carbon black on the autohesive tack (uncured adhesion between a similar pair of elastomers) [225]. It has been shown that the incorporation of carbon black at very high concentration (>30 phr) can increase the autohesive tack of natural and butyl rubber [225]. Very recently, for the first time, Kumar et al. [164] reported the effect of NA nanoclay (at relatively very low concentration) on the autohesive tack of BIMS rubber by a 180° peel test. XRD and AFM show intercalated morphology of nanoclay in the BIMS rubber matrix. However, the autohesive tack strength dramatically increases with nanoclay concentration up to 8 phr, beyond which it apparently reaches a plateau at 16 phr of nanoclay concentration (see Fig. 36). For example, the tack strength of 16 phr of nanoclay-loaded sample is nearly 158% higher than the tack strength of neat BIMS rubber. The force versus, distance curves from the peel tests for selected samples are shown in Fig. 37. 

Acharya et al. [26] and Gcwabaza et al. [28] used XRD to study the effects of nanoclay (OMMT) loading on the morphology of polymer blend nanocomposites for an ethylene propylene diene terpolymer (EPDM)ZEVA and a polypropylene/poly(butylene succinate) (PP/PBS) blend, respectively. Both studies showed an increase in the intensity of the diffraction peak due to nanoclay with an increase in the nanoclay loading, but the location (20) of the peak seems not to be affected by the increase of nanoclay loading. 

Figure 7.6 shows the effect of KE fiber length on tensile properties of nanobiocomposites. The tensile strength decreased with the addition of KE and nanoclay on the contrary, the tensile modulus showed the opposite. The tensile modulus of PP/KE (1 mm) and PP/KE (10 mm) nanobiocomposites with 10 wt% nanoclay loading increased 78.8% and 118.2% respectively, compared to that of PP nanocomposites. This is... 

Figure 7.7 shows the effect of nanoclay on the flexural (a) strength and (b) modulus of PP nanobiocomposites with different fiber length and nanoclay loadings. As shown in Figure 7.7, the flexural strength and modulus of PP nanobiocomposites also show a similar tendency to the tensile strength and modulus, respectively. 

Tsimpliaraki, A., Tsivintzelis, I., Marras, S. I., Zuburtikudis, I., and Panayiotou, C. 2011. The effect of surface chemistry and nanoclay loading on the microcellular structure of porous poly(D,L lactid acid) nanocomposites. Journal of Supercritical Fluids 57 278-287. 

P. K. Maji, P. K. Guchhait, and A. K. Bhowmick. Effect of the micro structure of a hyperbranched polymer and nanoclay loading on the morphology and properties of novel polyurethane nanocomposites. Applied Materials Interfaces, 12 (2009), 289-300. 

Ojijo V, Sinha Ray S, Sadiku R (2012) Effect of nanoclay loading on the thermal and mechanical properties of biodegradable polylactide/poly [(butylene succinate)-co-adipate] blend composites. ACS Appl Mater Interfaces 4(5) 2395-2405... 

The results suggest that the thermal stability improves with higher loading till 6 phr of nanoclay and this improvement is attributed to the barrier effect of the exfoliated and the intercalated nanoclay particles. 

Bandyopadhyay et al. [138] have also studied the distribution of nanoclays such as NA and 30B in NR/ENR (containing 50 mol% epoxy) and NR/BR blends and their effect on the overall properties of the resultant nanocomposite blends. They calculated the preferential distribution of clays at various loadings in the blend compounds from the viscoelastic property studies from DMA. The tensile properties of the 50 50 NR/ENR and 50 50 NR/BR blend nanocomposites are shown in Table 5. It is apparent that in both the blends that the mechanical properties increase with increasing clay concentration up to a certain extent and then decrease. These results have been found to depend on matrix polarity and the viscosity of the blend compounds. 

In combination with nanoclays, nanocomposites can be produced for a wide field of applications. Even low loadings of nanoclays with high aspect ratios to biopol5miers can have a profoimd enhancing effect over the material properties (42). Such nanocomposites have an improved strength and stiffness, a low gas vapor permeability, a low coefficient of thermal expansion, and an increased heat deflection temperature. However, in this field also some technical difficulties emerge, but these can be circumvented (40). 

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