Hybrid Materials and Systems

Abstract

Plastics were investigated based on homopolymers, which are polymers consisting of macromolecules characterized by the uniform chemical structure along the main chain, the successive investigation and related discovery demonstrated that the plastics’ behaviour could be reached with more complex systems in terms of molecular structure and composition. Successively copolymers consisting of macromolecules based on two different monomers have offered a possibility for designing plastics with a broader spectrum of properties. Going from molecular differentiation towards structural complexity, the mixing of polymers having different structures and thus different properties has provided a helpful tool to obtain materials with unique ultimate features, which are not characteristic of pristine macromolecules alone. At the same time, the dispersion in a polymer matrix of fillers having different aspect ratios (fibres, particles, lamellae) and dimensions (micro- and nanostructured fillers) can improve the thermo-mechanical properties or/and impart completely new properties, as example the barrier property, depending on the morphologies and dispersion level as well as on the interfacial interactions degrees. In fact, the blending procedure (between polymers or between polymer and filler) is effective only if proper interfacial interactions can be granted through the presence of specific functionalities. These latter can be naturally present onto both man-made and natural-made polymers or have to be inserted/anchored to the polymer backbone by post-reactor modification procedures. Therefore, this chapter summarizes the most important chemical post-modification procedures of polymers to prepare functionalized polymers or grafted copolymers suitable to act as compatibilizers , the main theoretical aspects of blending and the methodologies already get ready to provide composites and nanocomposites by using polymers from fossil, from renewable resources and even natural.