According to the presence situation that lignin-based SiO2 composite nanoparticles are difficult for industry application

owing to serious aggregation and low lignin capacity

phosphatized alkali lignin (PAL) was prepared through phosphorylation reaction using alkali lignin (AL) from the alkaline pulping spent liquor of poplar as main material. The lignin/silica composite nanoparticles (L-SiO2) was combined from 1 part nanosilica with 1.2 part (by mass) synthesized PAL by acidulation co-precipitation method. Subsequently

L-SiO2 was added into HDPE to prepare L-SiO2/HDPE composites. Results of FT-IR

XPS

TEM

TG and static contact angle showed that PAL was bonded to silica through hydrogen bonds. L-SiO2 accounted for 47% (mass) LQA. Compared to crude silica

the particle size of L-SiO2 increased from 25 to 40 nm and the agglomeration of particle decreased noticeably. More importantly

the surface of L-SiO2 became more hydrophobic

which made them disperse better in HDPE. The tensile strength and elongation at break of prepared L-SiO2/HDPE composites were 48.68% and 73.57%

respectively

higher than those of AL/HDPE.