(102c) Novel Chemistries and Engineering for the Replacement of Methylenedianiline in Composites

Authors: 
Cosgrove, J. D., Rowan University
Schmalbach, K. M., Rowan University
Stecca, O. M., Rowan University
Bassett, A. W., Rowan University
Paquette, C. M., Army Research Laboratory
Sadler, J., Army Research Laboratory
La Scala, J., Army Research Laboratory
Stanzione, J. F. III, Rowan University
4,4’-Methylenedianiline (MDA) is used to produce high temperature epoxy resins as well as other high performance composites; however, MDA is a known carcinogen and liver toxin. Added safety measures to prevent MDA exposure have increased manufacturing costs, driving the search for potential MDA replacements. Alternatives to MDA have not gained significant traction due to reduced performance, reduced confidence in the material, and they offer a small, if any, reduction in toxicity. In this paper, we present our work on developing structure-property-toxicity relationships of various substituted dianalines by examining the effect of molecular architecture on overall polymer performance and toxicity. Novel dianilines derived from both petroleum and biomass with different numbers of methyl and methoxy substituents on the aromatic ring were synthesized to decrease toxicity and carcinogenic aspects of the resulting material while maintaining thermal and mechanical integrity. Structure-toxicity relationships indicate that multiple substituents on the aromatic ring are necessary to severely reduce the toxicity of the dianiline. Structure-property relationships show that methoxy groups reduce the glass transition temperature and thermal degradation temperature while methyl groups only slightly affect these properties. The addition of substituent groups increases the melting point of the dianiline to varying degrees based on substituent placement.
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