Processing of Polymer Matrix Nanocomposites

José M. Kenny, Luca Valentini
European Centre for Nanostructured Polymers, University of Perugia, UdR INSTM,
Loc. Pentima Bassa 21, 05100 Terni, Italy
jkenny@unipg.it, www.ecnp.eu.org; www.unipg.it/materials

Carbon nanotubes (CNTs) are carbon structures with extraordinary mechanical, chemical and electrical properties. These unique properties make CNTs potentially valuable in a wide range of end-use applications. In particular, the use of CNT as nanofillers of thermoplastic and thermosetting polymer matrices allows the production of innovative materials with breakthrough structural and functional properties. However, the achievement of these properties requires a careful definition of processing routes and conditions able to produce nanocomposites with designed and controlled nanofiller dispersion, orientation and alignement. It is the aim of this research work to consider the approaches to controlled processing and chemical functionalization of CNT and to account for the advances that have been produced so far in the processing of these innovative materials.
Due to their exceptional mechanical, thermal and electrical properties, carbon nanotubes (CNTs) are extremely promising for the development of high performance nanostructured materials. Since their discovery in 1993 the research in this exciting field has been in continuous evolution, being most of the research focused on the assessment of the CNT properties and the development of advanced structural composites based on CNTs. Single-walled carbon nanotubes (SWNTs) are considered as the simplest member of the family of CNTs, consisting of one graphitic sheet, which has been rolled up into a cylindrical shape. Depending on the arrangement of the hexagon rings along the tubular surface, CNT can be metallic or semiconducting. However, the incorporation of nanotubes is not a trivial task mainly if a good dispersion for a chemical grafting to the polymer matrix are mandatory to maximize the advantage of nanotube reinforcement. In fact, the affinity to adhere to each other, renders as-grown SWNTs intractable and indispersable in common solvents.
On the other hand, it has been demonstrated that CNT can be made soluble when they interact with different classes of compounds. The key challenges that are in the way of realizing composites made out of carbon nanotubes are securing a reliable control over their surface chemistry through either covalent or non-covalent modification and achieving dispersion.
In this project we report some examples of nanocomposites with CNTs highlighting a meshwork of interactions between the mechanical, electrical and optical properties of CNTs and the interface with the polymer matrix with the aim to offer an overview on the approaches of processing and chemical functionalization of CNTs and to account for the advances that have been produced so far.
The use of electrical and magnetic fields as processing aids for the production of aligned nanocomposites is also reported.