Determination of Composite and Nanocomposite Structure by Rheological Measurements

TERENZI, ANDREA; KENNY, JOSÉ MARÍA; BARBOSA, SILVIA ELENA

Ischia, Italia

Conferencia; II International Conference on Times of Polymers (TOP); 2004

Universidad de Nápoles

The rheological properties of composites and nanocomposites are strongly associated with their structure. Particularly, the transient response of these materials permits to analyze several structural variables. In the case of fibers suspensions, the main variables associated with the rheological transient behavior are fiber orientation distribution, aspect ratio, aspect ratio distribution, fiber concentration and flexibility, and fiber-fiber interaction. Whereas in the nanocomposite with thermoplastic matrix, seems to be a strong dependence with the clay concentration, dispersion and intercalation. In this work, a method for structure analysis as a function of the transient rheological response is proposed. The transient first normal stress coefficient difference at the start up of the shear flow is the property to be measured in order to characterize the suspensions. Results shows that it is possible to determine if fiber suspensions have been done with flexible or rigid fibers. In the first case it was possible to determine by this method if the flexible fibers were well dispersed or not. In the second case it is possible to determine whether the suspension has random fiber orientation or not. On the other hand, with the same method, results that permit characterize the clay dispersion in a thermoplastic matrix nanocomposite were also obtained.