Thermal study of the effect of several solvents on polymerization of acrylonitrile and their subsequent pyrolysis

Abstract

The polymerization of acrylonitrile to polyacrylonitrile (PAN) has been studied using several solvents: N,N-dimethylformamide (DMF), hexane, toluene, water, and in bulk form (no solvent). The addition of DMF is the only case where both monomer and polymer are soluble in the solvent. Thermal analyses of the resultant products after polymerization have been performed by differential scanning calorimetry and pyrolysis-gas chromatography/ mass spectrometry. The effect of the solvents employed as media for polymerization is interpreted from the results of the thermal and structural (X-ray diffraction) methods. The polymer samples obtained when using water or toluene as solvents have the greater content of amorphous components compared to the others. The amide molecules are difficult to completely eliminate in the product obtained after the polymerization reaction and even after prolonged heating at 110°C and remain occluded. DMF can be considered to exert a plasticized effect on PAN and is even capable of forming complexes by dipolar bonding.

A review of heat treatment on polyacrylonitrile fiber

“…2, an essential and time-consuming step in the conversion of PAN fibers to high performance carbon fiber is the oxidative stabilization step [7]. This can be explained by chemical reactions that are involved in this process, which are cyclization, dehydrogenation, aromatization, oxidation and crosslinking which can result in the formation of the conjugated ladder structure [22,23].…”

Dynamic Prediction Models and Optimization of Polyacrylonitrile (PAN) Stabilization Processes for Production of Carbon Fiber

“…Hence, a trade-off needs to be made since thermal stabilization is the manufacturing bottleneck of carbon fiber production, and requires a significant amount of energy to power furnaces for a long period of time [10]. In carbon fiber manufacturing, it is ideal to stabilize fibers fully, and as quickly as possible.…”

“…The following equation shows a major relation between the components of the model. (10) where R is the gas constant and A is the frequency factor. Taking the reaction peak temperatures for each heating ramp into Eq.…”

Chemical Characterization of Stabilized and Carbonized Polyacrylonitrile (PAN) Fibers Treated with Oleic Acid.

“…Carbon fiber reinforced composite became more important in aerospace, civil engineering, military, and motorsports, along with other competition sports [1][2]. Carbon fibers can be derived from pitch based, polyacrylonitrile (PAN) polymer or rayon based chemicals.…”