Rheological Characterization of Droplet‐Matrix versus Co‐Continuous Morphology

The viscoelastic properties of phase‐separated poly(methyl methacrylate) (PMMA) and poly(styrene–co‐maleic anhydride) (SMA) blend systems have been investigated. It is shown that the samples of initial off‐symmetric and symmetric compositions show different characteristic viscoelastic properties, which are the reflections of different internal morphologies. Except for the well‐known characteristic deviations of the storage modulus at low frequencies, other rheological functions such as weighted relaxation spectrum, van Gurp–Palmen plots, and Cole–Cole plots also show significantly different shapes corresponding to droplet‐matrix and co‐continuous morphology. Based on these findings we propose that such characteristic fingerprints can be used for inferring the internal structure.

Keywords:

• rheology
• morphology
• droplet‐matrix
• co‐continuous

Acknowledgments

This research was supported by the National Natural Science Foundation of China (Grant No. 20204007, 20474039, 20490220, and 50390095). The polymer SMA samples used were generously donated by SINOPEC Shanghai Research Institute of Petrochemical Technology.