We have examined the effect of interfacially-active particles on the morphology and rheology of immiscible polymer blends with a droplet/matrix morphology. Experiments were conducted on a model system with less than 2 vol% of silica particles. The blends were examined by rheological experiments and Scanning Electron Microscopy (SEM). We find that particles that are preferentially-wetted by the drop phase are able to glue together two drops by bridging across them. The morphology therefore consists of particle-bridged clusters in which the individual drops are non-spherical. Such blends show strong gel-like rheological behavior and a yield stress. In contrast, particles that are equally-wetted by both phases are not capable of bridging across drops; the morphology consists of nearly-spherical drops and which are not clustered, and a yield stress is not evident. In summary, in polymer blends with added particles, the particle wettability has a major effect on the morphology and flow characteristics.

Effect of interfacially-active particles on the structure and rheology of immiscible polymer blends

244th National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.