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摘要
3,3%26apos;-Diaminodiphenyl sulfone (3,3%26apos;-DDS) was reacted with acetaldehyde in the presence of sodium triacetoxy borohydride via reductive amination to yield a 3,3%26apos;-DDS based secondary diamine, N,N%26apos;-diethyl-3,3%26apos;-diaminodiphenyl sulfone. Near IR analysis indicated that the 5060 cm-1 peak for primary amine (-NH2) in 3,3%26apos;-DDS was absent in the reaction product spectrum. The -NH2 proton peak at delta 5.66 ppm shifted to delta 6.16 ppm in the product. Methyl and methylene protons of CH3?CH2?NH?Ph? group were observed at delta 3.01 and 1.12 ppm, respectively, in the product. The carbon NMR spectrum of the reaction product showed new peaks at delta 37.46 and 14.47 ppm that further confirmed secondary amine formation. The liquid chromatography coupled mass spectra peaks at 248250 for 3,3%26apos;-DDS and 304 for the reaction product further supported the formation of N,N%26apos;-diethyl-3,3%26apos;-diaminodiphenyl sulfone. A blend of N,N%26apos;-diethyl-3,3%26apos;-diaminodiphenyl sulfone with diglycidyl ether of bisphenol-A (DGEBA) epoxy prepolymer started reacting at about 110125 degrees C surpassing an energy barrier of similar to 66 kJ/mol as determined via differential scanning calorimetry analysis. Reaction kinetics were characterized via near IR spectroscopy specific to the reaction between secondary amine and DGEBA epoxy prepolymer. The results confirmed %26gt;97% conversion at a cure protocol of 5 h at 80 degrees C, 5 h at 100 degrees C, 11 h at 125 degrees C, and 6 h at 185 degrees C. N,N%26apos;-diethyl-3,3%26apos;-diaminodiphenyl sulfone-DGEBA thermoplastics displayed tensile and flexural modulii of 3.08 and 2.86 GPa, respectively, and glass transition temperature (Tg) of 120.77 degrees C.
- 出版日期2012-12-15
