Structure and properties of conducting poly(o-phenylenediamine) synthesized in different inorganic acid medium

Synthesis of poly(o -phenylenediamine) nanofiber with novel structure and properties

“…a). In addition, the strong singlet peak was observed at 6.9 δ for the combined chemical shift of one aromatic C―H and chain substituted or terminal N―H groups . The existence of two singlet peaks at 6.9 δ was also confirmed from the proton ratio 1:1:2.3 obtained by the derivation of the peaks at 7.6, 7.9 and 6.9 δ.…”

“…Then, it was oxidized to cyclohexa‐3, 5‐diene‐1, 2‐diylidenediamine just like oxidation of p‐phenylenediamine to diamine especially in non‐aqueous medium, and the polymerization was occurred through this derivative of o‐phenylenediamine. Both the NH groups of cyclohexa‐3, 5‐diene‐1, 2‐diylidenediamine were protonated by only one molecule of sulfuric acid formed by reduction of APS, just like oPD polymerization in sulfuric acid medium . Then, the polymer structure like polyaniline derivative with free NH functional group substitutions was formed through the polymerization of only one protonated NH groups and its para position (Scheme ) .…”

“…Both the NH groups of cyclohexa‐3, 5‐diene‐1, 2‐diylidenediamine were protonated by only one molecule of sulfuric acid formed by reduction of APS, just like oPD polymerization in sulfuric acid medium . Then, the polymer structure like polyaniline derivative with free NH functional group substitutions was formed through the polymerization of only one protonated NH groups and its para position (Scheme ) . While the ladder structure was predominantly formed at monomer:APS ratio of 1:2.5 (mol:mol) because of the polymerization of both the protonated NH groups by two separate molecule of sulfuric acid as the amount of acid was produced higher at higher APS ratio .…”

“…a). Thus, it could be said that the thermal stability of the polymer was up to 280°C, and the stability was considered as more or less similar with that of the ladder type or open ring stucture polyphenylenediamine …”

“…Therefore, just like polyaminophenol, the synthesis of polyphenylenediamine containing free ―NH 2 functional groups might be given the importance for stable doping, improved processability and potential applications with the help of the polar functional groups . Recently, we have succeeded to synthesize the processable poly(o‐phenylenediamine) (PoPD) containing free ―NH 2 functional groups by adjusting the pH of the polymerization medium or by using aqueous sulfuric acid as polymerization medium . However, the properties especially film forming properties, doping abilities and conductivities of the reported polymers having uncertain structures and morphologies were not found to be impressive .…”