Effect of nanofillers addition on the compatibilization of polymer blends

The recent interest in multifunctional materials with tailorable performances led to the formulation of novel polymer blends, with enhanced properties with respect to traditional plastics and showing economical advantages compared to the synthesis of new polymers. However, polymer blends are immiscible in most cases, and proper compatibilization is therefore needed to obtain an alloy with suitable performances. Beside the traditional compatibilization approaches (i.e., addition of graft or branched copolymers, reactive compatibilization), a novel technique has recently emerged, based on the insertion of micro- and nanostructured inorganic fillers within polymer blends. Therefore, the aim of this review is to give an overview about the role played by nanofillers on the compatibilization of polymer alloys. A survey of the most important papers in literature on this topic will be presented, trying to correlate the microstructural features of nanofilled blends to their physical properties. After an introduction on the general aspects of polymer alloys in Chapter 1, the most relevant compatibilization strategies will be presented in Chapter 2, with particular emphasis on the compatibilization induced by micro- and nanostructured fillers. Chapter 3 will be focused on the nanofiller induced compatibilization, and several examples of thermoplastic, thermosetting and elastomeric nanofilled blends will be presented. Considering the increasing importance of biopolymers and of their blends in the modern industry, in Chapter 4 it will be shown how nanofiller induced compatibilization could be successfully applied also to bioplastics based alloys. Due to the recent environmental concerns on the polymer waste management and the difficulties in the plastics sorting operations, in Chapter 5 it will be demonstrated that nanomodification of recycled plastics can lead to blend recyclates with good compatibility and suitable physical properties. The key aspects of the nanofiller induced compatibilization in polymer blends and the future perspectives will be summarized in Chapter 6.