Abstract: Polyacrylic acid grafted alkali lignin/phenolic foam materials (PAA-g-AL/PF) was prepared by using polyacrylic acid grafted alkali lignin and phenolic resin.The influences of preparation conditions such as the additions of foaming agent, surfactant, toughening agent, the foaming temperature on their properties were studied.The morphology, functional groups, and thermal properties of PAA-g-AL/PF were investigated by SEM, FT-IR, DSC, and TGA.It was found that the optimum conditions to prepare PAA-g-AL/PF open-cell absorbent material were 50 g PF with the additions of PAA-g-AL 7%, foaming agent 16%, surfactant 8%, toughening agent 7%, 4.8g 10% hydrochloric acid solution, and the foaming temperature 62 ℃.Under these conditions, the water absorption of PAA-g-AL/PF was 33.08 g/g, the apparent density was 5.1 g/dm³, and it was thermally stable under 136 ℃.The obtained PAA-g-AL/PF was a uniform open-cell material and keeping its shape after absorbing water.

Key words: polyacrylic acid grafted alkali lignin, phenolic resin, open-cell, absorbent materials