The effect of organoclay platelets on morphologies of three blend compositions (80/20, 20/80, and 99.5/0.5 w/w) of nylon-6 (N6) and poly(ethylene-ran-propylene) rubber (EPR) has been studied by scanning and transmission electron micrographs. For the 80/20 (w/w) N6/ERP blend, the dispersed domain size (D) of EPR phase in the N6 matrix decreased significantly even if a small amount of the organoclay was added. The extent of the decrease in D in this blend was similar to N6/EPR blend with an in-situ reactive compatibilizer of EPR-g-maleic anhydride. The D of the blend with the clay did not change upon further annealing at high temperatures, which suggests that the clay seems to be an effective compatibilizer. But, for the 20/80 (w/w) N6/EPR blend, dispersed N6 domain did not decrease with increasing the amount of the clay up to 2 wt %. Moreover, the dispersed N6 domains were not stable against further annealing at high temperatures; thus, coalescence of N6 domains was observed. Furthermore, for 99.5/0.5 (w/w) N6/EPR blend dispersed EPR domains did not change with the amount of the clay. The results indicate that as long as the clay becomes exfoliated in the matrix, the exfoliated clay plates effectively prevent the coalescence of the dispersed domains.

The temporal change of complex viscosity (η*) of two plates consisting of an end-functional monocarboxylated polystyrene (PS−mCOOH) and poly(methyl methacrylates) (PMMA) with various amounts of poly(methyl methacrylate-ran-glycidyl methacrylate) (PMMA−GMA) was measured by a rotational rheometer. There were three distinct stages for the change of η* with time:  (i) stage I, where η* increased rapidly at short times and approached a steady value at later times; (ii) stage II, where η* did not change; and (iii) stage III, where η* increased slowly again and reached a final value. The apparent reaction kinetics obtained from the results in stage I was a first-order reaction. The change of the interfacial roughness between two plates with reaction time was investigated by transmission electron microscopy and atomic force microscopy after selective removal of unreacted PS−mCOOH layer. At long reaction times, the interface became pinched off, and then microemulsions (and micelles) were formed in the PMMA phase.

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Summary: The effect of chain architecture of in situ formed copolymers on the interfacial morphology of reactive polymer blends was investigated. We found that the chain architectures of copolymers at the interface significantly affected the reaction and interface roughness. Although the amount of in situ formed Y‐shaped graft copolymers was smaller than that for diblock copolymers, the interface area generated by the former was larger than that generated by the latter.Cross‐sectional TEM images for the mid‐sample reacted at 180 °C for different reaction times.imageCross‐sectional TEM images for the mid‐sample reacted at 180 °C for different reaction times.

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