Diglycidyl ether resins

Table 26.5 Properties of some anhydrides used in low molecular weight diglycidyl ether resins...

Low-viscosity diglycidyl ether resins of undisclosed composition" have been marketed in the United States and in Britain. The materials are stated to be totally difunctional, i.e. free from monofunctional reactive diluents. The cured resins have properties very similar to those of the standard diglycidyl ether resins. 

Compared with standard diglycidyl ether resins, the liquid cyclic aliphatic resins are paler in colour and have a much lower viscosity. Whereas in general the cyclic aliphatic resins react more slowly with amines, there is less difference with acid anhydrides. Table 26.7 provides data illustrating this point. 

As a consequence the resins are rather brittle. The high degree of cross-linking does, however, lead to higher heat distortion temperatures than obtained with the normal diglycidyl ether resins. 

The epoxidised polybutadiene resins available to date are more viscous than the diglycidyl ethers except where volatile diluents are employed. They are less reactive with amines but have a similar reactivity with acid anhydride hardeners. Cured resins have heat distortion temperatures substantially higher than the conventional amine-cured diglycidyl ether resins. A casting made from an epoxidised polybutadiene hardened with maleic anhydride and cured for two hours at 50°C plus three hours at 155°C plus 24 hours at 200°C gave a heat... 

Analytically, epoxy groups are determined by the reaction with hydrogen halide and back titration with a standard base. Other functional groups present may cause interference problems and result in poor end points. Pyridinium chloride-pyridine is a recommended reagent for the analysis of bisphenol-diglycidyl ether resins [22,23],... 

Bisphehol A Diglycidyl Ether Resin Isopropyl Mercaptan Isopbopyl Percarbonate Isopropyl Percarbonate P-Cymene... 

Bisphenol F Resins. Diglycidyl ether resins based on bisphenol F (DGEBF) have been developed to provide cured epoxy resins with greater flexibility and lower softening temperatures than conventional DGEB A epoxy resins. The preparation of bisphenol F resins is from formaldehyde and phenol. Three isomers are possible because substitution can occur at the ortho-, meta-, or para- positions. The proportion of isomers depends upon the pH of the reaction medium. 

The curing kinetics of curing reactions of bisphenol A diglycidyl ether resins has been studied in great detail under a NASA contract [122]. 

The cycloaliphatic resins are a paler colour than the standard diglycidyl ether resins and also have much lower viscosities. Typical examples are dicyclopentadiene dioxide, which is a solid at room temperature, and vinyl cyclohexene dioxide, which is a liquid... 

Epocryl resins. The vinyl esters are acrylate-terminated derivatives of diglycidyl ether resins, as shown with the derivative of bisphenol-A diglycidyl ether 1. 

Isosorbide diglycidyl ether resins replaced bisphenol-A epoxies for lining food and beverage cans. 

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