Injected polymer-matrix nanocomposites: morphology-performance relationship

VALERIA PETTARIN

Polymer-Matrix Composites: Types, Applications and Performance

Nova Science Publishers

Año: 2014; p. 129 - 166

Polymer nanocomposites are new materials that show great potential in a variety of applications. By incorporating nanoscale particles of a filler material, the performance and properties of the bulk material can be drastically altered. Indeed, quite exceptional improvements can be achieved with small amounts of filler. To make nanocomposites economically viable, their production must use common processing equipment, and additional processing steps should be avoided. Therefore, many thermoplastic-composites are processed by an injection molding process. It is generally accepted that the performance of polymer nanocomposites is intimately related to the degree of dispersion of the nanofiller: good dispersion and exfoliation may lead to the expected improvement in properties. This dispersion depends on factors such as the affinity and compatibility of the filler with the matrix, the matrix viscosity and the applied thermo-mechanical level, which depends on the processing conditions. The understanding of the fracture, micro-deformation and mechanics of failure of nanocomposites is crucial for engineers. In this chapter the relationship between processing and performance is reviewed for different injected thermoplastic pieces. The effects of the molding process and of the nanoclay filler on the properties of the polymer composites are reported. Also, the effect of the occurrence of in-homogeneities, such as weld lines or flow lines in microstructure and therefore in performance are summarized.