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|Title: ||Effect of structure of diamide-diimide-diamines based on L-methionine on curing behaviour and thermal stability of DGEBA|
Narula, A K
|Issue Date: ||Jun-2009|
|Abstract: || New L-methionine-based diacids containing imide units are synthesized via reaction of dianhydride (PMDA/ODA/NTDA) with L-methionine in the presence of a mixture of acetic acid and pyridine (3:2 v/v). A series of diamide-diimide-diamines (DADIDAS) was synthesized by activation of obtained diacids with thionyl chloride (SOCl2) and then condensation with excess of different aromatic diamines containing ether, methylene and sulfone units via high temperature condensation method. The DADIDAS prepared by reacting PMDA/NTDA/ODA with L-methionine (M) followed by condensation with 4,4'-diaminodiphenyether (E)/ 4,4'-diaminodiphenylmethane (M) and 4,4'-diaminodiphenyl sulfone (S) have been designated as PME, PMM, PMS, NME, NMM, NMS, OME, OMM and OMS. The diamide-diimide-diamines were examined by FT-IR, 1H and 13C NMR spectroscopy and elemental analysis. The curing behaviour of diglycidyl ether of bisphenol-A (DGEBA) with aromatic diamide-diimide-diamines was studied by Differential Scanning Calorimetry (DSC). The peak exotherm temperature (TP) was lowest in DGEBA cured using PMM and highest in DGEBA cured using NMS. Thermal stability of the isothermally cured DGEBA with diamide-diimide-diamines was investigated using dynamic thermogravimetry analysis (TGA) in nitrogen atmosphere and it was found that NTDA based diamide-diimide-diamines provide good stability to DGEBA. Char yield was found to be highest in the case of EOMM. |
|Appears in Collections:||IJC-B Vol.48B(06) [June 2009]|
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