Hydantoin amine-cured

Note that the highest IDT was obtained with the cyclopenta-methylenehydantoin resin derived from cyclohexanone. It is tempting to speculate that this inflexible alkylene moiety was ineffective in shielding the hydantoin ring, but subsequent comparison of the hydrophobic-hydrophilic balance of amine-cured resins appeared to rule out this explanation probably the stiff spiro structure contributed to the high Tg, just as it contributed to the high melting point of the resin itself (lie). 

Since the hydrophobic-hydrophilic balance of amine-cured resins was so sensitive to alkyl substituents on the hydantoin ring, it is not surprising that it was also sensitive to the hydrocarbon moieties of the amine curatives. The range of behavior depended on the resin substituents. For example, the already hydrophobic ethyl amyl substituted Resin Ilk showed moderate but significant increases in hydrophobicity when cured with cycloaliphatic, highly branched aliphatic, or formulated aromatic amines. See Table V. 

ROOM TEMPERATURE AMINE CURING OF HYDANTOIN EPOXY RESINS... 

SOLVENT RESISTANCE OF AROMATIC AMINE-CURED HYDANTOIN EPOXY RESIN... 

Steric factors - branching at or close to the hydantoin ring - raised the glass transition temperature while maintaining the shielding effect. Amines of different structures were used as room temperature curatives with a few representative resins, to observe the effect on hydrophilic-hydrophobic balance. Solvent effects were examined on aromatic amine-cured resins the most hydrophilic cured system proved to have the broadest range of lyophobicity. 

Adding amines to coating compounds containing other polymers of hydantoin derivatives permits thermal curing of the coating compounds, which are useful as electrical insulators of wires under a broad range of conditions without loss of coating flexibiUty (101). 

The hydrophobic shielding of the hydantoin ring by alkyl substituents affected all the solvent-solute interactions of cured resins. Two of the resins and the DMH-based resin mixture were cured with a commercially available aromatic amine mixture derived from aniline-formaldehyde condensation, identified in Table VII. Weight gain and solvent plasticization were followed in a number of solvents and aqueous media. Some of the exposure was at 60 C as well as at room temperature. 

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