Effect of Activated Lignin Biochar with Different Alkali Material Ratios on the Properties of Lignin Biochar/HDPE Composites
Using lignin as precursor and potassium hydroxide(KOH)as activator,lignin biochar(LBC)with different alkali material ratios(the mass ratio of KOH to lignin)was prepared via pyrolysis.Using LBC as filler and the high density polyethylene(HDPE)as matrix,LBC/HDPE composite materials were prepared via an open mill-hot pressing process.The functional groups and pore structures of LBC were characterized,and the performances of LBC/HDPE were tested.The results show that the polar functional groups of LBC decrease after the high-temperature carbonization.At low alkali material ratio,LBC mainly forms micropores.At high alkali material ratio,the pore formation behavior is further strengthened,and the micropores develop into mesopores or macropores.When the mass ratio of KOH to lignin is 5 ∶1,LBC has the highest specific surface area and pore volume,reaching at 1 835.48 m2/g and 1.34 cm3/g,respectively.With the increasing of alkali material ratio,the dispersibility and compatibility of LBC in HDPE are improved,and the interfacial microphase separation phenomenon of the composite material is weakened.When the mass ratio of KOH to lignin is3 ∶ 1,the comprehensive mechanical properties of LBC3/HDPE composite material are superior,whose tensile,bending and impact strength are 29.11 MPa,27.87 MPa and 7.11 kJ/m2,respectively.The LBC addition can improve the thermal stability,storage modulus and loss modulus of the composite materials.
Alkali Material RatioLignin BiocharMechanical PropertyHigh Density PolyethyleneCompositeRheological Behavior
NETL
NSTL
万方数据
