Please use this identifier to cite or link to this item:
|Title:||Effect of structure of diamide-diimide-diamines based on L-methionine on curing behaviour and thermal stability of DGEBA|
Narula, A K
|Abstract:||<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="metricconverter"> New L-methionine-based diacids containing imide units are synthesized <i>via</i> 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 (SOCl<sub>2</sub>) and then condensation with excess of different aromatic diamines containing ether, methylene and sulfone units <i>via </i>high temperature condensation method. The DADIDAS prepared by reacting PMDA/NTDA/ODA with L-methionine (M) followed by condensation with 4<b>,</b>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, <sup>1</sup>H and <sup>13</sup>C 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 (T<sub>P</sub>) 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. </smarttagtype>|
|Appears in Collections:||IJC-B Vol.48B(06) [June 2009]|
Items in NOPR are protected by copyright, with all rights reserved, unless otherwise indicated.