Highly efficient melt polymerization of diaminomaleonitrile

An XPS study of HCN-derived films on pyrite surfaces: a prebiotic chemistry standpoint towards the development of protective coatings

“…15,19 Moreover, it is well known that the synthetic conditions allow tuning of the structural characteristics and extension of the properties of HCN polymers. 15,[20][21][22] Mineral surfaces could potentially have allowed for almost any type of general catalysis, with low specicity and efficiency, in several prebiotic environments. Among these mineral surfaces, pyrite (FeS 2 ) is crucial for explaining the iron-sulfur world hypothesis about the origin of a possible protometabolism.…”

Kinetic Study of the Effective Thermal Polymerization of a Prebiotic Monomer: Aminomalononitrile

“…Therefore, the unique exothermic process close to ~175 °C might be related with a very rapid exothermic decomposition, which masks the melting endothermic process in an analogous way to that suffered by the 2-oximemalononitrile [ 29 ] or with a polymerization process similar to the thermal polymerization of DAMN. For this compound, to lower the temperature, before the melting point, the peak was detected due to the solid-state polymerization of DAMN and, at a higher temperature, its melting polymerization [ 19 , 20 ].…”

“…Furthermore, no melt could be observed before polymerization, in agreement with the fact that the pure AMN is an oil [ 3 , 5 ]. Thus, this result indicates that both nitrile monomers, AMN and DAMN, can be thermally polymerized, yielding a conjugated heterocyclic system with isolated or conjugated nitrile groups, C≡N [ 19 , 20 ]. In the present particular case, the broad and poorly resolved region centred at ~1640 cm −1 could correspond to heterocyclic systems, since, in general, azoles have three or four bands in the region of 1670–1320 cm −1 due to C=C and C=N stretching, with intensities that depend on the substituent, the position, and the nature of the ring heteroatoms [ 31 ].…”

“…DSC measurements were performed on a DSC 7 (Perkin Elmer, Norwalk, CT, USA) calibrated with high-purity chemicals. Temperature-ramping DSC studies were performed from 25 to 250 °C, in accordance with the previous studies on the thermal polymerization of DAMN [ 19 , 20 ], at heating rates ( β s) of 2.5, 5, 10, 15, 20, and 25 °C/min in a dry nitrogen atmosphere at a rate of 20 mL/min, using approximately 4–5 mg of AMNS placed in aluminium pans. After the non-isothermal reactions, the samples were rapidly cooled to room temperature, and heating scans at 20 °C/min were performed.…”

“…This technique, in addition to simultaneous thermal analysis coupled with mass spectrometry (TG-MS), was chosen to analyze AMNS under dynamic thermal conditions, since they have been proven to be extremely useful in understanding the kinetic, thermodynamic, and likely pathways of DAMN polymerization. TG-MS has allowed for the evaluation of gaseous species generated during the polymerization reactions to gather more information about the mechanism [ 19 , 20 ]. This fact has motivated the choice to apply this methodology to the thermal reaction of AMNS to know the relevant aspects of such process.…”