The influence of reaction conditions in aqueous HCN polymerization on the polymer thermal degradation properties

A Comparative Study on HCN Polymers Synthesized by Polymerization of NH4CN or Diaminomaleonitrile in Aqueous Media: New Perspectives for Prebiotic Chemistry and Materials Science

“…Almost all polymers studied herein contained 38–40 % carbon, 37–39 % nitrogen, 3–4 % hydrogen and 16–20 % oxygen (Figures S3 and S4 in the Supporting Information). In contrast, it is well known that HCN polymers are hygroscopic and contain between 5 and 10 % of adsorbed water . Thus, thermogravimetric analysis (TGA) of all the studied polymers was performed to establish the water content (see below).…”

“…The rest of the observed endothermic processes corresponded to the decomposition processes of the polymers. The peak‐fitting simulation of the DSC curves would allow detection of differences among NH 4 CN and DAMN polymers as well as among polymers of the same series, but this is beyond the scope of the present work. However, we note that the shapes of the DSC curves recorded in this work for NH 4 CN polymers synthesized at 80 °C were clearly different from those of NH 4 CN polymers synthesized at lower temperature .…”

“…The peak‐fitting simulation of the DSC curves would allow detection of differences among NH 4 CN and DAMN polymers as well as among polymers of the same series, but this is beyond the scope of the present work. However, we note that the shapes of the DSC curves recorded in this work for NH 4 CN polymers synthesized at 80 °C were clearly different from those of NH 4 CN polymers synthesized at lower temperature . Again, the degradation thermal techniques offered a fingerprint for HCN polymers beyond the information provided by the raw FTIR spectra and even NMR spectra in solid state.…”

“…However,w en ote that the shapes of the DSC curves recorded in this work for NH 4 CN polymers synthesized at 80 8Cw ere clearly different from those of NH 4 CN polymers synthesized at lower temperature. [3,35] Again, the degradation thermalt echniques offered af ingerprint for HCNp olymers beyond the informationp rovided by the raw FTIR spectra [3] and even NMR spectra in solid state. The DSC curves allowed distinction between NH 4 CN polymers synthesized at moderate temperatures (20-40 8C) and those synthesized at higher temperature.…”

“…In contrast, it is well known that HCN polymers are hygroscopic and contain between 5a nd 10 %o fa dsorbed water. [3,35] Thus, thermogravimetric analysis (TGA) of all the studied polymers was performed to establish the water content (see below). The weights of oxygen and hydrogen corresponding to the water content were calculated and subtractedf rom the experimental elemental analysis data.…”