Final Morphology of Reactive Blends

Reactive compatibilization has two key effects on the final morphology of polymer blends reduction of the average size of the dispersed phase domains and narrowing of the size distribution. Both of these effects have been demonstrated by a number of workers [5,45-51]. In continuous/dispersed systems, the size of dispersed phase domains may be 

400 domains in three different fields of view are required to obtain accurate statistics. Polydispersity ratios d and dv/4i ay be used to quantify the breadth of the size distribution. 

Oshinski et al. [54] suggested that the weight average diameter of a blend could be represented by  

As described above in the section on morphology development, there are several separate mechanisms responsible for the effects of the interfacial reaction on the final morphology. Empirical means may be used to separate some of these simultaneous effects. For example, Scott and Macosko [41] successfully separated the effects of increased mixing torque and changing component rheologies as a fimction of temperature from other effects of the chemical reaction. They utilized Wu s [55] empirical equation for rubber particle diameters in reactive blends with polyamide 66 and poly(ethylene terephthalate) prepared in twin screw extruders  

The (-f) sign in the exponent applies when A 1 and the (—) sign when A 1. This relationship provides for a minimum dispersed phase size when A = 1. However, it is noteworthy that this relationship was obtained for blends with dispersed phase concentrations of approximately 20wt.% and thus certainly includes effects of coalescence. The 

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