Microfibril cellulose (MFC), which is detrimental to soil cultivation and environmental protection, is derived from waste pineapple leaves. Hexagonal boron nitride (h-BN) was modified with polydopamine (PDA)-PDA@h-BN named pBN, and then combined with MFC to prepare a novel hybrid powder. The effect of PDA on h-BN and the binding effect between pBN and MFC were characterized by X-ray photoelectron spectroscopy (XPS), Thermogravimetric (TG), scanning electron microscopy (SEM), and Fourier Transform-Infrared (FT-IR). Poly (vinyl alcohol) (PVA) was used as an eco-friendly polymeric matrix to prepare a pBN-MFC-PVA composite film. The mechanical strength, hydrophobicity, and thermal conductivity of the film were studied and the results confirmed that h-BN was chemically modified with PDA and was uniformly distributed along the MFC. The thermal conductivity of the pBN-MFC-PVA composite film increased with the addition of a pBN-MFC novel powder. MFC acted as "guides" to mitigate the h-BN agglomerate. In addition to the possible usage in the pBN-MFC-PVA composite film itself, the pBN-MFC hybrid powder may be a potential filler candidate for manufacturing thermal interface materials and wearable devices or protective materials.
Keywords: composite; flexibility; hexagonal boron nitride; microfibril cellulose; thermal conductivity.