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Synthesis, spectral, and thermal characterization of photoreactive epoxy resin containing cycloalkanone moiety in the main chain
Author(s) -
Devi R.,
Murugavel S. C.
Publication year - 2011
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/app.35028
Subject(s) - epoxy , polymer chemistry , thermogravimetric analysis , epichlorohydrin , polymerization , fourier transform infrared spectroscopy , cyclopentanone , cationic polymerization , chemistry , materials science , cyclohexanone , differential scanning calorimetry , oligomer , organic chemistry , polymer , chemical engineering , physics , engineering , catalysis , thermodynamics
Abstract Dual functional epoxy resins were synthesized by solution polycondensation of 2,6‐bis(4‐hydroxy‐3‐methoxy benzylidene)cyclohexanone and 2,5‐bis(4‐hydroxy‐3‐methoxy benzylidene)cyclopentanone with epichlorohydrin. The synthesized epoxy resins were characterized systematically for their structure by UV, Fourier transform infrared (FTIR), 1 H NMR, and 13 C NMR spectroscopic techniques. Thermal characterization of synthesized epoxy resins was carried out by thermogravimetric analysis, and differential scanning calorimetry (DSC) under nitrogen atmosphere. The self extinguishing property of synthesized oligomers was studied by determining limiting oxygen index (LOI) values using Van Krevelen's equation. X‐ray analysis showed that the epoxy resins containing cyclopentanone have higher degree of crystallinity. The photoreactive property of the synthesized epoxy resins in solution and film states was investigated by UV–Vis spectroscopy. The photocross‐linking proceeds through the dimerization of olefinic chromophore present in the main chain of the oligomer via 2π + 2π cycloaddition reaction. The influence of photoacid generator on the rate of photocross‐linking of epoxy resin was studied by FTIR. UV irradiation of the epoxy resin in presence of photoacid generator produces aromatic sulfonium cation radicals and aromatic radicals which initiate the cationic ring‐opening polymerization of oxirane ring. The photoreactivity studies of the oligomers by FTIR and DSC indicated the presence of dual functionality in the synthesized epoxy resins. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012