Rubber nanocomposites blending methods

This is truly reflected in the morphology of the uncured clay preexfoliated rubber nanocomposite films (NLu NA) prepared by the latex blending method (Fig. 7a). Curing the NR/NA nanocomposites in situ prevulcanization (No>NA) does not alter the arrangements of dispersed clay layers greatly, as seen from the... 

Only limited success has been achieved in compounding organomontmoriUonites with styrene—butadiene rubber to prepare rubber nanocomposites [51], Knudson et al. [51] discovered that flocculation of the aqueous blend of styrene-butadiene latex and montmorOlrMiite gives an exfoliated clay-rubber nanocomposite. The approach offers the most convenient and effective method for the preparation of clay-styrene-butadiene rubber nanocomposites. 

An alternative method of producing natural rubber based clay reinforced nanocomposites with outstanding properties is by using a spray drying technique. In this technique the siUcate layers of clay will be well dispersed in an irradiated polymer latex and this mixture will be sprayed through hot air to produce micrometre-sized liquid droplets. When the solvent is fully evaporated, micrometre-sized polymer spheres with delaminated clay silicate layers on their surface are produced. These spheres can later be melt blended with natural rubber to produce ternary nanocomposites. It is noteworthy that exfoliation of nanofillers can still be achieved without modification of the nanofiller surface, thus the expensive modification process can be eliminated. 

Boonmahitthisud et al., prepared natural rubber/carboxylated styrene butadiene rubber (NR/XSBR) (80/20) nanocomposites containing different loadings of carbon nanotube (CNT) (0.1-0.4 phr) by a latex stage compounding method. The dynamic mechanical properties, in terms of tan 8 and E, of the neat 80/20 NR/XSBR blend and its nanocomposites were evaluated from —80 to 100 °C. Figure 21 shows the influence CNT loadings, on the tan 8 and E as a function of temperature for the nanocomposites [100]. 

This is the most promising method and it has great advantages over both previously mentioned methods being both compatible with current industrial processes and environmentally benign, due to the absence of solvents. In this method rubber and modified layered silicate mixture are blended in the molten state under shear. The rubber chains reptate from the molten mass into the silicate galleries to form either intercalated or delaminated nanocomposites. ... 

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