On the Chromophore of Polyacrylonitrile. VI. Mechanism of Color Formation in Polyacrylonitrile

A review of heat treatment on polyacrylonitrile fiber

“…The mechanism for colouration is not fully understood. However, the appearance of black colour is believed to be due to the formation of ladder ring structure [28,29].…”

“…[53] (2) the chain end groups; [54] (3) random initiation by hydrogen atoms a to the nitrile; [55] (4) transformation of a nitrile to an azomethine; [56];(5) the presence of a ketonitrile formed by hydrolysis during polymerization; [28] and (6) hydrolysis of nitriles to acids during polymerization [57]. In addition, due to their reaction, cyclization reactions can proceed in either an inert atmosphere or in the presence of oxygen.…”

Continuous and rapid stabilization of polyacrylonitrile fiber bundles assisted by atmospheric pressure plasma for fabricating large-tow carbon fibers

“…1c). Friedlander et al reported that the color changes of PAN polymer are related to a form of cyclization due to the crosslinking of adjacent nitrile units [15]. The tensile strength and modulus of CFs carbonized using the PAN fibers and stabilized by plasma are shown in the Fig.…”

Acrylonitrile-based copolymers: Synthesis, characterization, and formation of ultrafiltration membranes utilized for the immobilization of proteins

“…The total enzymatic activity of a n average mAS membrane was 34.1 units/m2 of area, where a unit is 1 pmol of product formed per minute at 25.0"C at pH 8.5. The specific activity of the immobilized CT was 0.024 units/mg of protein, which represents 42% of the activity of soluble enzyme towards GPNA.…”