Design of high-toughness polyacrylamide hydrogels by hydrophobic modification
POLYMER, cilt.50, sa.23, ss.5449-5455, 2009 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 50 Sayı: 23
- Basım Tarihi: 2009
- Doi Numarası: 10.1016/j.polymer.2009.09.042
- Dergi Adı: POLYMER
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.5449-5455
- Anahtar Kelimeler: Hydrogels, Toughness, Elasticity, MULTISTICKER ASSOCIATIVE POLYELECTROLYTES, TRANSIENT NETWORK THEORY, MICELLAR COPOLYMERIZATION, NANOCOMPOSITE HYDROGELS, RHEOLOGICAL PROPERTIES, BEHAVIOR, GELS, PROPERTY, STRENGTH, FRACTURE
- Marmara Üniversitesi Adresli: Evet
Özet
Polyacrylamide (PAAm) hydrogels possessing a very large extensibility at break have been prepared via micellar crosslinking copolymerization of acrylamide monomer and N,N'-methylenebis(acrylamide) crosslinker in the presence of hydrophobic comonomers. N-butyl-, N-hexyl-, N-octyl-, and N,N-dihexylacrylamides were used as the hydrophobes in the hydrogel preparation. Incorporation of hydrophobes with an alkyl chain length x > 4 results in an increase in the loss factor tan 6 of hydrogels due to the formation of temporary junction zones inside the gel network. The number N-H of the hydrophobes per hydrophobic block together with the alkyl chain length x of the pendant hydrophobic group were used to tune the loss factor of the hydrogels over two orders of magnitude. Tensile mechanical measurements show that increasing N-H or x also increases the degree of toughness of PAAm hydrogels. Keeping constant the hydrophobe level (20 mol%) at an alkyl chain length x=6, increasing N-H from 9 to 30 increased the elongation ratio at break from 125 to 250%. Hydrogels exhibiting a high toughness, i.e., about 300% elongation ratio at break were obtained by modification of PAAm network chains with 10 mol% N-octylacrylamide. (C) 2009 Elsevier Ltd. All rights reserved.