A novel functional silica/lignin hybrid material as a potential bio-based polypropylene filler

A functional silica/lignin hybrid filler was obtained using a process of mechanical grinding of precursors (Syloid®244 silica and kraft lignin). The product underwent comprehensive physicochemical and dispersive–morphological analysis. The silica/lignin hybrid has good homogeneity and a surface area of 164 m2/g. The effectiveness of combination was confirmed by Fourier transform infrared spectroscopy and elemental analysis. The high electrokinetic stability (over almost the whole of the analyzed pH range) and above all the thermal stability of the resulting material (mass loss equal to 12%) indicate its potential use as a polypropylene (PP) filler. Experiments showed that the incorporation of a small amount of silica/lignin hybrid filler into PP may substantially influence its elongation at break and notched impact strength. Especially at low concentrations of silica/lignin filler (below 5 wt%) an exceptional set of mechanical properties was obtained. The addition of larger amounts of the filler was found not to bring any further improvement. POLYM. COMPOS., 36:913–922, 2015. © 2014 Society of Plastics Engineers