TGMDA resins

The effects of impurities, or synthesis byproducts, and stoichiometry on the cure kinetics of N,N -tetraglycldyl methylene dianiline (TGMDA) resins formulated with dlaminodiphenyl sulfone (DDS) are evaluated using gel permeation chromatography and differential scanning calorimetry. 

DSC Study. From the analysis of the total heats of reaction of the commercial and fractionated TGMDA resin/DDS formulations over a broad stoichiometric range, it is concluded that the total heat of reaction divided by the epoxy concentration has a constant value... 

Both GPC and DSC show that impurities or reaction byproducts in commercial TGMDA resins increase the rate of reaction. This effect is illustrated in Figures 8 and 9 where the epoxy/amine equivalent ratios are held constant. Impurities also tend to lower g, reduce the gelation time, increase M at g, and increase Ofjnai The magnitude of these effects are particularly notable upon comparing the DSC parameters of the TGMDA and Residue formulations (Table IV). 

DSC Parameters for the Isothermal Cure of TGMDA Resin/ /eg. epoxy... 

An egulvalence between the exotherms for the epoxy-amine addition and the epoxy-epoxy polymerization reaction simplifies the interpretation of data and permits the direct comparison of TGMDA resins having gulte different compositions. For TGMDA/DDS reactions, increasing the epoxy/amine eguivalent ratio -... 

The TGMDA resins Araldite MY720 (batch No. 5093) and Glyamine G-120 (Lot Mo. 1003) were obtained recently from Ciba-Gelgy Corp. and FIC Corp., respectively, and were stored in closed containers at -13°C. The purification was conducted in two stages using a Waters Associates Prep LC/System 500 with Prep PAK-500/Silica columns. 

Figure 1. Size Exclusion HPLC of Cotmneroial TGMDA Resins.

Figure 2. Reverse Phase HPLC of Commercial TGMDA Resins.

Figure 6. Hydrolytic Stability of TGMDA Resins at 60 C and 96% RH. Reverse Phase HPLC Analysis,...

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