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Synthesis and properties of partially hydrolyzed acrylonitrile-co- acrylamide superabsorbent hydrogel

Pourjavadi, A ; Sharif University of Technology | 2010

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  1. Type of Document: Article
  2. DOI: 10.5012/bkcs.2010.31.11.3163
  3. Publisher: 2010
  4. Abstract:
  5. In this work, a novel method to synthesis of an acrylic superabsorbent hydrogel was reported. In the two stage hydrogel synthesis, first copolymerization reaction of acrylonitrile (AN) and acrylamide (AM) monomers using ammonium persulfate (APS) as a free radical initiator was performed. In the second stage, the resulted copolymer was hydrolyzed to produce carboxamide and carboxylate groups followed by in situ crosslinking of the polyacrylonitrile chains. The results from FTIR spectroscopy and the dark red-yellow color change show that the copolymerization, alkaline hydrolysis and crosslinking reactions have been do take place. Scanning electron microscopy (SEM) verifies that the synthesized hydrogels have a porous structure. The results of Brunauer-Emmett-Teller (BET) analysis showed that the average pore diameter of the synthesized hydrogel was 13.9 nm. The synthetic parameters affecting on swelling capacity of the hydrogel, such as AM/AN weight ratio and hydrolysis time and temperature, were systematically optimized to achieve maximum swelling capacity (330 g/g). The swollen gel strength of the synthesized hydrogels was evaluated via viscoelastic measurements. The results indicated that superabsorbent polymers with high water absorbency were accompanied by low gel strength. The swelling of superabsorbent hydrogels was also measured in various solutions with pH values ranging from 1 to 13. Also, the pH reversibility and on-off switching behavior makes the hydrogel as a good candidate for controlled delivery of bioactive agents. Finally, the swelling of synthesized hydrogels with various particle sizes obey second order kinetics
  6. Keywords:
  7. Acrylamide ; Hydrogel ; Superabsorbent ; Acrylamides ; Acrylonitrile ; Alkaline hydrolysis ; Ammonium persulfate ; Bioactive agents ; Brunauer emmett tellers ; Carboxamides ; Carboxylate groups ; Color changes ; Controlled delivery ; Copolymerization reactions ; Crosslinking reaction ; Free radical initiators ; FTIR spectroscopy ; Gel strengths ; High water ; In-situ ; Novel methods ; Partially hydrolyzed ; pH value ; Pore diameters ; Porous structures ; Second order kinetics ; SEM ; Super absorbent ; Superabsorbent hydrogel ; Superabsorbent polymer ; Swelling capacities ; Switching behaviors ; Synthetic parameters ; Two stage ; Viscoelastic measurements ; Weight ratios ; Acrylic monomers ; Acrylics ; Amides ; Ammonium compounds ; Carboxylation ; Copolymerization ; Fourier transform infrared spectroscopy ; Free radicals ; Gels ; Hydrolysis ; Organic polymers ; Scanning electron microscopy ; Swelling ; Synthesis (chemical) ; Hydrogels
  8. Source: Bulletin of the Korean Chemical Society ; Volume 31, Issue 11 , 2010 , Pages 3163-3172 ; 02532964 (ISSN)
  9. URL: http://koreascience.or.kr/article/ArticleFullRecord.jsp?cn=JCGMCS_2010_v31n11_3163