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Study on superabsorbent composite. XI. Effect of thermal treatment and acid activation of attapulgite on water absorbency of poly(acrylic acid)/attapulgite superabsorbent composite
Author(s) -
Wang Wenji,
Li An,
Zhang Junping,
Wang Aiqin
Publication year - 2007
Publication title -
polymer composites
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.577
H-Index - 82
eISSN - 1548-0569
pISSN - 0272-8397
DOI - 10.1002/pc.20299
Subject(s) - acrylic acid , superabsorbent polymer , composite number , materials science , swelling , composite material , hydrochloric acid , swelling capacity , grafting , chemical engineering , monomer , polymer , engineering , metallurgy
The effect of acid activation and thermal treatment of attapulgite on water absorbency of superabsorbent composite were investigated. Under the same preparation conditions, superabsorbent composite prepared with natural attapulgite exhibited a water absorbency of 639 g/g and it merely kept 71% of its initial water absorbency after 5 times of swelling–deswelling–reswelling test. However, superabsorbent composites prepared with 2–10 M hydrochloric acid acidified attapulgite and 100–400°C thermal treated attapulgite respectively exhibited the water absorbency of 884–1,241 g/g and 701–1,515 g/g. Also, those superabsorbent composites can keep 87% and 85% of their initial water absorbency after 5 times of swelling–deswelling–reswelling test, respectively. These results showed that, compared with superabsorbent composite prepared with natural attapulgite, the comprehensive water‐absorbing properties of poly(acrylic acid)/ attapulgite superabsorbent composites were improved effectively by acid activation and thermal treatment of attapulgite. This improvement of water absorbencies and gel strength of superabsorbent composite may be due to synthetical factors such as changes in the crystalline structure and the specific surface area and improvement of the number and the activity of hydroxyl groups of attapulgite, which in turn influence the grafting efficiency of monomer, crosslinking density, and the structure of superabsorbent composite network. POLYM. COMPOS., 28:397–404, 2007. © 2007 Society of Plastics Engineers