| Abstrakt: |
ABSTRACT Carvacrol and p-cymene are sustainable and versatile starting materials for the preparation of hydrophobic monomers. These molecules can be readily derived from pine resin or produced from other sustainable feedstocks via a biosynthetic approach. A hydrophobic epoxy monomer [bis(2-isopropyl-5-methyl-4-(oxiran-2-ylmethoxy)phenyl)methane, 3] with methyl and isopropyl substituents on the aromatic rings was synthesized from carvacrol. A bisaniline [4,4′-methylenebis(5-isopropyl-2-methylaniline, 4] was then synthesized from p-cymene. Using a cured epoxy-amine network prepared from the diglycidyl ether of bisphenol A ( DGEBA) and 4,4′-methylenedianiline ( MDA) as a baseline system, three additional networks were prepared from DGEBA: 4, 3: MDA, and 3: 4. The cured epoxy-amine networks were tested for moisture uptake as well as changes in thermomechanical properties after exposure to boiling water for several days. Incorporation of the bio-based monomers resulted in up to 53% lower water uptake compared to the baseline system. The bio-based resins also showed greater resistance to degradation under hot-wet conditions, with wet-TG knockdowns as low as 8% as compared to a 19% decrease for the baseline system. These results show that the unique functionality of the renewable bisphenol and aniline used in this study can result in materials with improved hot/wet performance as compared to conventional thermosetting resins. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43621. [ABSTRACT FROM AUTHOR] |
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