Bio‐based hydrophobic epoxy‐amine networks derived from renewable terpenoids

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.

Synthesis and characterization of a high temperature thermosetting polyimide oligomer derived from a non-toxic, sustainable bisaniline

“…6 The lower observed T g for PMR-PCy was expected based on the slightly lower volumetric cross-link density due to the extra aliphatic groups. This slight decrease in T g was in stark contrast to that previously observed for a cyanate ester with similar aliphatic groups 26 and related epoxy-amine networks, 25 which exhibited decreases of ca. 60 C and 30 C, respectively.…”

“…For example, epoxy amine thermoset networks prepared from a bisaniline (CDA, Scheme 2) and epoxy monomer, both derived from p-cymene, showed substantially lower water uptake and a reduced "wet" T g knockdown compared to a baseline system comprised of DGEBA and MDA. 25 Further, a cyanate ester thermoset network containing the p-cymene moiety was shown to have one of the lowest water uptakes ever observed for a polycyanurate. 26 Thus, the p-cymene structure has the potential to reduce the water uptake of thermosetting polyimides and improve hot-wet mechanical properties.…”

“…4,4 0 -Methylenebis-(5-isopropyl-2-methylaniline) (CDA) was prepared as previously described. 25 No living animals were used in the performance of this research. All toxicological testing was conducted in in vitro systems employing cells of either bacterial or eukaryotic origin.…”

Determination of Moisture Sorption Isotherm of Crosslinked Millet Flour and Oxirane Using GAB and BET

“…erefore, the effect of moisture on epoxy network and its properties were studied [3][4][5][6]. Studies show that water absorption can disrupt hydrogen bonds among segments of the polymers and cause swelling and increase in diffusion coefficient of water within the polymer.…”

Improving the homogeneity of sugarcane bagasse kraft lignin through sequential solvents

“…Technical lignin, which is derived from black liquor from papermaking, is primarily incinerated for steam production and power generation. Only a small quantity (<2%) 1 of the lignin worldwide produced is used to produce some high value-added products, such as dispersants, 2,3 adhesives, 4 antioxidants, 5,6 and carbon ber. 7,8 As people pay more and more attention to environmental issues, lignin has received more and more attention as an environmentally friendly and renewable material.…”