Rheology of Reactively Compatibilized Polymer Blends

However, it is of great interest to understand how the copolymer, which comprises the gel, is spatially distributed in the blend. During the processing it is certainly formed at the interface or interphase between the immiscible components. However, it may be moved away from the interface during subsequent mixing. Instead, it may exist as a layer around the dispersed rubber phase. The copolymer could also exist within the rubber and/or polystyrene phases. 

Although these questions have not been definitively answered, in this particular case one potential spatial distribution of the copolymer may be eliminated. One might postulate that the dramatic effects on the rheological properties are can be attributed to the presence of a spherical shell of gel around the dispersed phase domains in the blends. However, it can easily be demonstrated that this is not the case. Assuming that the gel exists in a spherical shell around the dispersed phase domain, it is possible to model quantitatively the rheology of the reactive blends. The volume fraction of gel was estimated from the measured gel weight fractions. For direct application of the models it is necessary to know 

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Asthana Himanshu, and Jayaraman Krishnamurthy. Rheology of reactively compatibilized polymer blends with varying extent of interfacial reaction. Macromolecules. 32 no. 10 (1999) 3412-3419. 

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