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Substituent effects on thermal and photo‐alignment behavior of poly(ethylene imine)s carrying azobenzene side groups
Author(s) -
Kamruzzaman Mohammad,
Kuwahara Yutaka,
Ogata Tomonari,
Ujiie Seiji,
Kurihara Seiji
Publication year - 2011
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.2997
Subject(s) - azobenzene , substituent , side chain , materials science , alkyl , polymer , imine , photochemistry , pendant group , polymer chemistry , differential scanning calorimetry , chemistry , crystallography , organic chemistry , composite material , physics , catalysis , thermodynamics
A new class of liquid‐crystalline poly(ethylene imine)s (PEIs) having four differently substituted (CN,C 4 H 9 ,OCH 3 andNO 2 ) azobenzene side‐chain groups attached through alkyl spacer groups were successfully synthesized using a solution polycondensation reaction. The synthesized polymers were characterized using differential scanning calorimetry, polarized optical microscopy and X‐ray diffraction. The photochemical, thermo‐optical and photo‐orientational behavior of the polymers were investigated in detail. Spin‐coated films of PEIs with azobenzene groups havingC 4 H 9 ,OCH 3 andNO 2 substituents showed out‐of‐plane molecular orientation on annealing. Except for the PEI with an azobenzene group having NO 2 substituent, all polymers exhibited good photoresponsive properties upon irradiation with UV and visible light. Films of PEIs with azobenzene side groups havingCN,C 4 H 9 andOCH 3 substituents showed reversible alignment behavior from random state to out‐of‐plane and from out‐of‐plane to random state on annealing and on irradiation with UV and non‐polarized visible light. The reversibility of the molecular orientation of PEIs from random state to out‐of‐plane and from out‐of‐plane to random state greatly depended on the substituent attached to the azobenzene side‐chain group. Copyright © 2010 Society of Chemical Industry