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Thermo‐ and pH‐responsive behaviors of graft copolymer and blend based on chitosan and N ‐isopropylacrylamide
Author(s) -
Kim So Yeon,
Cho Sung Min,
Lee Young Moo,
Kim Seon Jeong
Publication year - 2000
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/1097-4628(20001114)78:7<1381::aid-app90>3.0.co;2-m
Subject(s) - chitosan , grafting , ceric ammonium nitrate , copolymer , polymer chemistry , poly(n isopropylacrylamide) , materials science , thermogravimetric analysis , swelling , lower critical solution temperature , monomer , fourier transform infrared spectroscopy , polymer , chemical engineering , nuclear chemistry , chemistry , composite material , engineering
Thermo‐ and pH‐sensitive polymers were prepared by graft polymerization or blending of chitosan and poly( N ‐isopropylacrylamide) (PNIPAAm). The graft copolymer and blend were characterized by Fourier transform‐infrared, thermogravimetric analysis, X‐ray diffraction measurements, and solubility test. The maximum grafting (%) of chitosan‐ g ‐( N ‐isopropylacrylamide) (NIPAAm) was obtained at the 0.5 M NIPAAm monomer concentration, 2 × 10 −3 M of ceric ammonium nitrate initiator and 2 h of reaction time at 25°C. The percentage of grafting (%) and the efficiency of grafting (%) gradually increased with the concentration of NIPAAm up to 0.5 M , and then decreased at above 0.5 M NIPAAm concentration due to the increase in the homopolymerization of NIPAAm. Both crosslinked chitosan‐ g ‐NIPAAm and chitosan/PNIPAAm blend reached an equilibrium state within 30 min. The equilibrium water content of all IPN samples dropped sharply at pH > 6 and temperature > 30°C. In the buffer solutions of various pH and temperature, the chitosan/PNIPAAm blend IPN has a somewhat higher swelling than that of the chitosan‐ g ‐NIPAAm IPN. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1381–1391, 2000