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The curing behavior of diglycidyl ether of bisphenol-A(DGEBA) with aromatic diamide-diimide-diamines having aryl ether,sulfone and methylene linkages was studied by differential scanning calorimetry(DSC).Nine diamide-diimide-diamines of varying structure were synthesized by reacting 1 mole of dianhydride with 2 moles of L-cysteine(S) in a mixture of acetic acid and pyridine(3:2 V/V) followed by activation with thionyl chloride(SOCl_2) and then condensation with excess of diamines.Structural characterization of diamide-diimide-diamines was done by using FTIR,~1H-NMR,~(13)C-NMR spectroscopy and elemental analysis.The peak exotherm temperature(T_P) was lowest in DGEBA cured using EPSM and highest in DGEBA cured using ENSS.Thermal stability of the isothermally cured DGEBA with diamide-diimide-diamines was investigated using dynamic thermogravimetry(TGA) in nitrogen atmosphere,and it was found that NTDA based diamide-diimide-diamines provided good stability to DGEBA.The char yield was highest for resin cured with ENSE which might be due to the presence of more compact structure i.e.naphthalene.
The curing behavior of diglycidyl ether of bisphenol-A (DGEBA) with aromatic diamide-diimide-diamines having aryl ether, sulfone and methylene linkages was studied by differential scanning calorimetry (DSC) reacting 1 mole of dianhydride with 2 moles of L-cysteine (S) in a mixture of acetic acid and pyridine (3: 2 V / V) followed by activation with thionyl chloride (SOCl_2) and then condensation with excess of diamines. structural characterization of diamide-diimide-diamines was done by using FTIR, ~ 1H-NMR, ~ (13) C-NMR spectroscopy and elemental analysis. peak inotherm temperature (T_P) was lowest in DGEBA cured using EPSM and highest in DGEBA cured using ENSS . Thermal stability of the isothermally cured DGEBA with diamide-diimide-diamines was investigated using dynamic thermogravimetry (TGA) in nitrogen atmosphere, and it was found that NTDA based diamide-diimide-diamines provided good stability to DGEBA. The char yield was highe st for cured cured with ENSE which might be due to the presence of more compact structure intended naphthalene.