Exceptionally flame-retardant flexible polyurethane foam composites: synergistic effect of the silicone resin/graphene oxide coating

Abstract

A facile strategy was developed to fabricate flexible polyurethane (PU) foam composites with exceptional flame retardancy. The approach involves the incorporation of graphene oxide (GO) into a silicone resin (SiR) solution, which is then deposited onto a PU foam surface via the dip-coating technique and cured. Fourier-transform infrared spectroscopy, scanning electron microscopy, and Raman spectroscopy measurements demonstrated that the SiR and GO were successfully coated onto the PU skeleton and the intrinsic porous structure of the PU foam remained intact. The effects of SiR and GO on the mechanical and thermal stability and flame retardancy of PU composites were evaluated through compression tests, thermogravimetric analysis, vertical combustion tests, and the limiting oxygen index. The measurement results revealed that the composites (PU@SiR-GO) showed superior flame retardancy and thermal and mechanical stability compared to pristine PU or PU coated with SiR alone. The mechanical and thermal stability and the flame-retardant properties of the PU composites were enhanced significantly with increasing GO content. Based on the composition, microstructure, and surface morphology of PU@SiR-GO composites before and after combustion tests, a possible flame-retardance mechanism is proposed. This work provides a simple and effective strategy for fabricating flame-retardant composites with improved mechanical performance.

Graphical abstract

Keywords

flame retardancy / flexible polyurethane foam / graphene oxide / silicone resin

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Acknowledgements

This work was supported by the National Key Research and Development Program (Grant No. 2017YFB0307700), and the Department of Scientific and Technology of Zhejiang Province (LGG18E030007, LGG19E030007), and the Project for the Innovation of High Level Returned Overseas Scholars (or team) in Hangzhou. We also acknowledge the support from Collaborative Innovation Center of Zhejiang Province for the Manufacture of Fluorine and Silicone Fine Chemicals and Materials (FSi2018A028, FSi2018B004), and professional development project for domestic visiting scholars in universities (FX2017054).

Electronic Supplementary Material

Supplementary material is available in the online version of this article at https://doi.org/10.1007/s11705-020-1988-8 and is accessible for authorized users.

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