Gerhard F. L. Ehlers

The Infrared Spectra of Some New Derivatives of S-Triazine

The infrared spectra of a number of new ethers, amino derivatives, and sulfur-containing s-triazines have been obtained in the region between 3333 and 670 cm−1. An interpretation of the spectra is given and some new assignments are made In addition the existance of certain hydroxy and thiol derivatives in the keto and thioketo configuration is shown

Correlation between structure and thermal stability of epoxy resins

A number of polycarboxylic acids, anhydrides, phenols, amines and catalysts, were evaluated as curing agents for epoxy resins and the resulting resins screened for thermal stability. As the basic resin molecule, Bisphenol A was also replaced by other diphenols. The thermal behaviour of these resins was related to their structure. In spite of a certain instability of the ester bond, the anhydride-cured resins gave the highest heat distortion and the best ageing stability. The BF3-amine complex is effective as a catalyst, especially with resins having more than two epoxy groups. Phenols and amines as curing agents gave low heat distortion values. Of the anhydrides investigated pyromellitic dianhydride is best, followed by maleic anhydride. Chlorendic anhydride, which gives fast curing and high heat distortion, has low ageing stability. Replacement of Bisphenol A as-the basic resin by naphthalene, diphenyl or diphenylsulphone derivatives might raise the heat distortion. However, structures like Resin B seem to be more promising.

THERMOSETTING PLASTICIZERS FOR HIGH TEMPERATURE QUINOXALINE THERMOPLASTICS

Recent studies in this laboratory have been concerned with a novel approach to the processing of high temperature thermoplastics. A series of bis (ethynylquinoxaline) monomers were prepared to demonstrate the feasibility of using thermosetting plasticizers in the processing of polyphenylquinxolaine thermoplastics.