Nanocomposites and nanomaterials
Nanoreinforced bio-based polyurethane foams with improved mechanical performance
L. Gryshchuk1, S. Grishchuk1, A. Minigher2, P. Campaner2, M. Ornelas3, C. Silva3, O. Pinkas4, Y. Nevo4, E. Döpelheuer5

1 – Institut fuer Verbundwerkstoffe GmbH, Erwin-Schroedinger-Str., 58, 67663 Kaiserslautern, Germany. 
E-mail: Liudmyla.Gryshchuk@ivw.uni-kl.de
2 – AEP Polymers SRL, Strada Statale 14, km 163.5, 34149 Basovizza – Trieste, Italy
3 – CENTITVC - Centro de Nanotecnologia e Materiais Tecnicos Funcionais e Inteligentes Associacao, Rua Fernando Mesquita 2785, 4760 034 Vila Nova de Famalicão, Portugal
4 – Melodea Ltd, 76100 Rehovot, Israel
5 – Kroppenstedter Ölmühle Walter Döpelheuer GmbH, Wilhelm-Firse-Str. 6, 39397 Kroppenstedt, Germany

Limited oil reserves and global environmental pollution with low-decomposable plastic waste move society to the post-petroleum phase and stimulate a big demand on the development of advanced bio-based materials. Among others, development of environmentally friendly, cross-material and intelligent industrial and service solutions can make large key industries safer, more sustainable, more comfortable and more energy efficient. Particularly, construction and automotive sectors provide the highest potential for exploitation of novel biomass derived polymer and composite materials. Special attention should be paid for cellular materials being widely used in these sectors. It is noteworthy that more than three quarters of the global consumption of polyurethane (PUR) products is in the form of foams, from soft to rigid types. PUR-based rigid foams are largely used in the construction industry due to their unique heat insulating properties, mechanical performance and high lightweight potential, whereas in the automotive industry soft and semi-rigid PUR-foams are mostly used for various interior parts. However, most of them are fully petroleum based.
The scope of present work includes the development of competitive multifunctional, sustainable PUR-based foams with low thermal conductivity, high hydrolysis and fire resistance and high thermal and mechanical properties for large construction and automotive industries. 
Commercially available bio-polyols were used for development of bio-based foam formulations, i.e. rigid foams for construction applications and district heating insulations, and soft foams for vehicle interiors. In this study, water and/or cyclopentane were served as blowing agents. Petroleum based additives were used at this development stage. Nevertheless, it was shown that biomass derived polyols provide high potential for replacement of petroleum based ones, whereas bio-based additives can be served for at least partial replacement of synthetic surfactants and/or catalysts. 
For improving the mechanical performance of new bio-based PUR-foams advanced (bio)nanofillers such as nanographene, nanocellulose and biomass-derived nanosilica were used (Fig.1). 

Figure 1 Examples of new foam samples

Despite some adjustment of nanoreinforced foam formulations was required in most cases, the resulted foams provided improved mechanical performance and showed high potential for application in various construction and automotive applications.

Acknowledgement
This work has been performed under the framework of the ReInvent project (Grant number 792049) funded by the H2020-BBI-JTI-2017 joint undertaking initiative.
Authors thank BASF Personal Care and Nutrition GmbH and Cardolite Corporation for providing the bio-based polyols and Evonik Industries AG for supply with catalysts and additives for PUR-based foams.