DGEBA—See Diglycidyl ether

DGEBA. See Bisphenol A, diglycidyl ether. Bisphenol A, diglycidyl ether (DGEBA) [1675-54-3]... 

Dezincing, lead refining by, 14 754-755 DGEBA-aromatic polyamine adduct system, 10 416, 417. See also Diglycidyl ether of bisphenol A (DGEBA)... 

The prepolymer stage in most cases is DGEBA (diglycidyl ether bisphenol A) (see Fig. 15.2a). 

Some of the first commercial conductive epoxy adhesives were simply based on silver powder dispersed in a liquid epoxy resin [e.g., diglycidyl ether of bisphenol A (DGEBA)] with an aliphatic amine [e.g., triethylene tetramine (TETA)] as a curing agent. Although capable of room-temperature cure, commercialization of this type of system was hampered by severe mix ratio disparity (typically, 50 1 by weight), problematic mixing due to viscosity differences, short pot life, and safety concerns. See Table 3 for typical properties of this type of formulation. 

Table 10.6 Comparison of some stoichiometric, fully cured epoxide-amine networks Tg, glass transition temperature [Ar], aromatic group concentration F, flex parameter (see text) n, crosslink density and [OH], hydroxyl concentration. Note DGEBD = diglycidyl ether of butane diol DGEBA = diglycidyl ether of bisphenol A (i = degree of polymerization) and TGAP = triglycidyl derivative of p-aminophenol ...

The best-known vinyl ester is made by reacting the diglycidyl ether of bisphenol-A (DGEBA see Section 16.4.2) with a monocarboxylic unsaturated acid such as methacrylic or acrylic acid see Scheme 16.24. This addition reaction occurs at a temperature of 120-140°C. The vinyl ester urethanes, on the other hand, are synthesized from a low molecular weight (unsaturated) polyester diol, mostly based on bisphenol-A, a diisocyanate, and a hydroxyalkyl (meth)acrylate (see also Schemes 16.30 and 16.31, Section 16.8.3.3). As for standard UP resins, the most commonly used reactive solvent is styrene. Both types of products have only a few ester linkages (which are the points of greatest vulnerability to chemical attack) in the mole-... 

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