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Substituted glycolurils are of considerable interest for the synthesis of cucurbit[n]uriltype macrocyclic receptors. Thus, the present work investigates the formation and characterization of tetrahydroimidazo[4,5-d]imidazole-2,5(1H,3H)dione (D glycoluril) and its derivatives. Acidcatalysed condensation reactions of these substances with formaldehyde lead to different products, depending on the reaction conditions chosen. Tetracyclic diethers are formed at low temperatures and long reaction times. Oligomeric chains are produced at temperatures higher than 50 ± C. Chains of suitable length are able to close in a cyclocondensation reaction under the formation of macrocyclic compounds of the cucurbit[n]uril type.

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The manufacturing of high-performance carbon fibers (CFs) from low-cost textile grade poly(acrylonitrile) (PAN) homo-and copolymers using continuous electron beam (EB) irradiation, stabilization, and carbonization on a kilogram scale is reported. The resulting CFs have tensile strengths of up to 3.1 ± 0.6 GPa and Young's moduli of up to 212 ± 9 GPa, exceeding standard grade CFs such as Toray T300. Additionally, the Weibull strength and modulus, the microstructure, and the morphology of these CFs are determined.

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