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A series of dual conducting polymer based type I supercapacitors were constructed using poly͑3,4-propylenedioxythiophene͒ and poly͑3,4-ethylenedioxythiophene͒ as electrode couples. The switching speeds and cycle lifetimes of these supercapacitors were compared using two types of supporting electrolytes; lithium bis͑trifluoromethanesulfonyl͒imide and 1-ethyl-3-methyl-1-Himidazolium bis͑trifluoromethanesulfonyl͒imide ͑a room temperature molten salt͒. The results indicate that supercapacitors using 1-ethyl-3-methyl-1-H-imidazolium bis͑trifluoromethanesulfonyl͒imide as the supporting electrolyte have cycle lifetimes superior to supercapacitors using lithium bis͑trifluoromethanesulfonyl͒imide as the supporting electrolyte.

Decreases of up to 50% in the moisture uptake of polycyanurate networks based on 2,2-bis(4-cyanatophenyl)propane (BADCy) and 1,1-bis(4-cyanatophenyl)ethane (LECy) were observed when analogous networks containing a single methyl group ortho-to each aryl−cyanurate linkage were prepared by reduction and acid-catalyzed coupling of salicylic acid followed by treatment with cyanogen bromide and subsequent cyclotrimerization. The differences in water uptake were observed despite similar decreases in packing fraction as conversion proceeded in all networks studied. Conversely, the presence or absence of methyl groups at arylene bridges, remote from the cyanurate oxygen, had no influence on water uptake. Vitrification during cure had little effect on either free volume development or moisture uptake. These results confirm that steric hindrance from ortho-methyl groups inhibits absorption of water presumably by decreasing the thermodynamic favorability of sterically permitted interaction with the cyanurate oxygen. A further examination of the effect of two different catalysts, 2 parts per hundred of a 30:1 by weight mixture of nonylphenol and copper(II) acetylacetonate and 500 ppm of dibutyltin dilaurate (DBTDL), compared to analogous uncatalyzed networks, showed that hydrolytic stability was dramatically affected by catalyst choice, while thermochemical stability was also impacted. These results provide important insights into the mechanisms that determine structure−property relationships in polycyanurate networks.

Four alkyl diamondoids, 1-pentyladamantane (PA), 2-butyladamantane (BA), 2-propyladamantane (2-PrA), and 2-ethyladamantane (EA), were synthesized on a preparative scale, and key fuel properties, including density, net heat of combustion, low-temperature viscosity, and derived cetane number (DCN), were measured. The fuel molecules had densities up to 17% higher than conventional jet fuel and volumetric net heats of combustion comparable to or exceeding that of the synthetic missile fuel JP-10. Remarkably, the alkyl diamondoid fuels had DCNs in the range of 42–49, which should allow for their efficient combustion in diesel engines. PA, BA, and 2-PrA all had essentially the same DCN (∼49), while the short alkyl chain in EA lowered the value to 42.7. Bond dissociation energies for the formation of diradicals from 2-PrA and PA were calculated with density functional theory methods to gain a qualitative understanding of potential combustion mechanisms. Ring opening of the adamantane core during combustion is proposed to explain the high cetane number of these fuels. The alkyl diamondoids described in this report are the first examples of multicyclic hydrocarbons that combine extraordinary densities (>0.9 g/mL) with DCNs comparable to or exceeding that of conventional diesel fuel.

Resveratrol is a sustainable and versatile bio-derived phenolic compound that has shown promise as a high glass-transition temperature (T g), flame-resistant building block for thermoset networks. In this study, three components of epoxy thermoset resins were synthesized from resveratrol: trans-resveratrol trisepoxy (1), dihydroresveratrol trisepoxy (2), and a trifunctional amine, 4,4′-((5-(4-(4-aminophenoxy)­phenethyl)-1,3-phenylene)­bis­(oxy))­dianiline (4). The epoxy monomers were low melting solids (mp < 80 °C) or thick oils consisting of primarily monomeric trisepoxides. Toxicity testing of 4 revealed that it was not mutagenic and had a low LD50 of 560 mg/kg, an aquatic toxicity of >2000 mg/L, and no cytotoxicity up to its solubility limit. The epoxy monomers were cured with 4,4′-methylenedianiline (3) and 4 to produce four epoxy–amine networks (A–D). Networks C and D, prepared with the resveratrol-derived aniline, contained up to 52.6% bio-based material. The moisture uptake, thermal stability, and dry/wet thermomechanical properties of the networks were measured. The networks had T g’s as high as 285 °C, approximately 110 °C higher than networks based on petroleum-derived bisphenol A (BPA). In addition, the resveratrol networks had char yields as high as 51 and 46% in nitrogen and air, respectively, compared to ca. 15 and 5%, respectively, for BPA-based networks. Overall, this study shows the advantages of resveratrol-based epoxy and amine monomers as components of sustainable, low-toxicity, high-temperature resin systems.