Study on superabsorbent composite - VII. Effects of organification of attapulgite on swelling behaviors of poly(Acrylic acid-co-acrylamide)/sodium humate/organo-attapulgite composite

摘要

A novel multifunctional superabsorbent composite from acrylic acid (AA), acrylamide (AM), sodium humate (SH) and organo-attapulgite (organo-APT), PAA-AM/SH/organo-APT, was synthesized by aqueous solution polymerization, using N,AT-methylenebisacrylamide (MBA) as a crosslinker and ammonium persulfate (APS) as an initiator. The organification of APT with hexadecyltrimethyl ammonium bromide (HDTMABr) was proved by FT-IR. The effects of organo-APT (HDTMA-APT) content in the superabsorbent composite and organification degree of it on water absorbency of the superabsorbent composite were studied. The effects of incorporated HDTMA-APT on swelling rate, water absorbency in various saline solutions and reswelling capability of the superabsorbent composite were also investigated. The results indicate that organification of APT had a remarkable influence on swelling behaviors of the superabsorbent composites. Comparing with the composite doped with APT, water absorbency for the composite incorporated with 10 wt% HDTMA-APT was enhanced from 996 to 1282 gg{sup}(-1) in distilled water and from 63 to 68 gg{sup}(-1) in 0.9 wt% NaCl solution, respectively. The superabsorbent composite acquired its highest water absorbency when the organification degree of APT was 8.02 wt%. Water absorbency of the composites in various saline solutions decreased with the increasing concentration, especially for the multivalent cations. In addition, swelling rate and reswelling capability of the superabsorbent composite were also improved by introducing HDTMA-APT into the composite compared with that of incorporating APT.