(300a) The Factory of the Future: Integrating Multiscale Modeling and Experiments to Produce New, Better Nanocomposite Materials

Nanocomposite materials hold the potential to redefine traditional thinking of the performances and fields of application of polymers. Indeed, nanocomposites can offer improved properties of thermoplastics including flame retardancy, tensile strength, mechanical moduli, barrier and heat distortion  temperature, just to name a few. However, developing state-of-the-art manufacturing technologies required to commercialize these opportunities still remains one of biggest challenge for the plastics industry.

The main goal of the 6^th Framework Program EU Integrated Project (IP) MULTIHYBRIDS was to develop an innovative factory of the future with integrated technologies for the preparation of advanced specialty materials based on industrially important new polymer hybrids and nanocomposites. The objective-driven approach was the in-process tailoring of materials with successive validation of the approach through on-line characterisation of the process, properties, and targeted performance of the newly produced nanomaterials.

Special innovations developed during MULTIHYBRIDS included on-line extrusion monitoring, new melt processing technology (“sol/gel extrusion”), and new approaches to exploit functional fillers and to prepare easy-to-disperse masterbatches. The in-situ compatibilization was the key to allow selective nanoreinforcement of polymer blends such as rubber-toughened thermoplastics with improved toughness/stiffness balance and increased heat distortion temperature. The process management for in-line monitoring was totally different from those currently employed off-line tests.

Moreover, during the entire project, multiscale molecular modelling was used for interpreting and predicting the properties of the materials of interest. Information derived from atomistc level simulations were used as input for the subsequent level of computation, namely mesocale simulations. At each step of the progress of the work, computer simulations at all scales were integrated in the project, and the calculated results were compared to the available experimental evidences.

The performances of a nanocomposite depends on many factors: (i) the chemistry of the components, (ii) the size and shapes of the nanofiller, (iii) the degree of dispersion and (iv) the nanofiller loading. All these issues are relevant and it is of paramount importance to be able to predict the effect of such independent variables on the final properties of the material. This contribution considers all these aspects and applies different molecular modeling methods, such as atomistic Molecular Mechanics and Molecular Dynamics, the mesoscale Dissipative Particles Dynamics and the macroscale Finite Element Method for the prediction of mechanical, thermal and barrier properties (taken as representative of the performances of a nanostructured material) for systems based on maleated polypropylene. The nanofillers considered are: montmorillonite, hydrotalcite, bohemite, sepiolite, carbon nanotubes and titania nanoparticles.

Finally, the process management object of this IP brought unambiguous advantages in terms of time and energy consumption and waste: process adjustments can be made in real-time minimising the need of time-consuming off-line tests (total time typically in the order of hours) and the production of unsuitable (waste) materials. Furthermore, the maximisation of simultaneous nanocharge funcionalisation/modification and nanocomposite formation can allow solvent-free processes favouring environmentally friendly productions.