Abstract:

Kaolin/sodium lignosulfonate graft acrylic acid and acrylamide superabsorbents composites(LPAAM) were prepared by solution polymerization using sodium lignosulfonate(LS-Na), acrylic acid(AA)and acrylamide(AM)as raw materials, kaolin as inorganic filler, potassium peroxydisulfate(KPS) as initiator, N,N'-methylene-bis-acrylamide(NMBA)as crosslinker. The optimized formula using orthogonal experiment design based on the assessment of the absorbencies in distilled water and 0.9%NaCl solution was obtained as follows: m(AM) ∶m(AA)=1 ∶1, m(KPS)=1.0%, m(NMBA)=0.1%, pH=3. Then the saponification reaction based on the above-mentioned optimized formula superabsorbent was used with different concentration NaOH solution at 90 ℃ for 2 h. Its absorbencies in distilled water and 0.9% NaCl aqueous solution were respectively 1 003 and 89 g · g^-1.

Key words: lignin, superabsorbents composites, solution polymerization, absorbency, kaolin