Water-absorbent resin,as a kind of functional polymers,was widely used in various fields,such as medicine and health care,agriculture,forestry and gardening,desert control,etc.Utilizing biomass resources to synthesizing water-absorbent resin as a new research direction have driven a strong global interest due to environment pollution.Lignin,as the second most abundant renewable biopolymer in nature,has been a candidate for renewable materials.In this paper,the water-absorbent resins were synthesized from lignosulfonate and acrylic acid(AA)by grafting copolymerization under aqueous solution with potassium persulfate as initiator and N'N-methylene-bis-acrylamide as crosslinking agent,which are compared to several other kinds of lignins under the same reaction conditions.Lignosulfonate was tried by using the single-factor method,the optimum process parameters in this experiment system are obtained(in wt％): acrylic acid 30％,lignosulfonate 2.67％(to AA),cross-linker 0.03％(to AA),initiator 0.43％(to AA),and neutralization 65％,the optimum reaction temperature was 60 °C.Under these conditions,the water absorbency of the lignosulfonate resin was 1348 g/g in deionized water.Comparing of thewater absorption properties of these synthetic resins from different kinds of lignin,the results showed that,lignosulfonate resin(1348 g/g)＞ lignocresol resin(1262 g/g)＞＞alkali lignin resin(518 g/g)＞ polyacrylic acid resin 439 g/g).Lignocresol is anovel lignin,it is synthesized through phase separation system,the introduced cresol can be changed into catechol,resorsicol or pyrogallol according to the application purpose,the higher water absorbent potential can be concluded.
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