Dielectric and mechanical characterization of aryl ester dendrimer/PET blends

The structure property relationships of miscible blends of two aryl ester dendrimers with poly(ethylene terephthalate) (PET) have been investigated. Although dielectric studies show relatively small effects on the glass transition process, the addition of dendrimers to PET produces a significant modification of the tensile drawing behaviour which may be interpreted in terms of the stretching of a molecular network. The smaller of the two dendrimers investigated acts as a plasticizer and reduces the chain entanglement density of the blend, whereas the larger dendrimer acts as an antiplasticizing agent and increases the entanglement density.