Na-neutralized ionomer

The crystallization rate of ternary blends is slower than that of the binary blends, and the ternary blends, which include Zn-neutrahzed ionomer, showed slower crystallization rate than ternary blends that included Na-neutrahzed ionomer (35). According to the literature, IPNs that possess physical interlocking at interfaces, strongly restrict crystallization (16,37). This IPN structure is postulated for the dynamically vulcanized EPDM and ionomers, especially for the blends containing Zn-neutralized ionomer. When the ionomer content was 5 wt%, the PP and EPDM blends are incompatible, that is, their phases are separated and the domain of EPDM was peeled off from the continuous matrix of PP (35). For the dynamically vulcanized EPDM and PP/ionomer ternary blends with 15 wt% ionomer, compatibiliza-tion was achieved between the PP and EPDM phases. The Zn-neutralized ionomer showed a much better compatibilizing effect than Na-neutralized ionomer. 

Figure 14.16 SEM microfractographs of highly vulcanized ternary blends (a) EPDM/PP/Na-neutraUzed ionomer (47.5/47.5/5), (b) EPDM/PP/Na-neutralized ionomer (40/40/20), (c) EPDM/PP/Zn-neutrahzed ionomer (47.5/47.5/5), and (d) EPDM/PP/Zn-neutraUzed ionomer (40/40/20). The initial crack length was 8 mm and DCP content is 1.00 phr (From Reference 38 with permission from Springer.)...

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