Synthesis, electrical properties, and kinetic thermal analysis of polyaniline/ polyvinyl alcohol - magnetite nanocomposites film

Abstract

Polyaniline-poly vinyl alcohol (PANI-PVA) conducting blends containing 15 wt% aniline were synthesized by in situ polymerization of aniline. Three-phase polymer blended nanocomposites with different contents of magnetite (5, 10 and 15 wt.%) were also synthesized. We measured the current-voltage (I-V) curves for the conducting blend and its magnetite nanocomposite. We also measured their thermal stability, and performed kinetic analysis through thermogravimetric analysis. We observed that the three phase nanocomposites showed enhanced electrical conductivity compared with that of the conductive blend, and no electrical hysteresis. The PVA/PANi blend was more stable above 350∘C and the addition of Fe3O4 enhanced the thermal stability of the conductive blend. The apparent activation energy of the three phase nanocomposites was greater than those of both the pure PVA and PVA/PANi samples. These results suggest that such three phase nanocomposites could be used in a range of applications.

Physicochemical Characteristics and Antibacterial Activities of Freeze-Thawed Polyvinyl Alcohol/Andrographolide Hydrogels

“…The decomposition curves of PVA, AG, and the PVA/AG hydrogels as presented in Figure were taken from the thermogravimetric analyzer test. The decomposition of PVA powder occurred in three phases, as reported by previous studies . The first phase was at temperatures below 100 °C, caused by the evaporation of adsorbed water and water bound in the hydrogel network of polymer molecular chains, mainly through hydrogen bonds.…”

“…The decomposition of PVA powder occurred in three phases, as reported by previous studies. 81 The first phase was at temperatures below 100 °C, caused by the evaporation of adsorbed water and water bound in the hydrogel network of polymer molecular chains, mainly through hydrogen bonds. In the second phase, there was a significant weight reduction between 211 and 339 °C due to a decrease in hydroxyl groups, producing a conjugated structure.…”

Thermal Analysis of the Biodegradable Polymer PVA/PEO Blends

“…In the second stage at 265 °C (T onset2 ) hydroxyl groups from PVA are eliminated. Finally, for the third stage at approximately 421 °C (T onset3 ) a conjugated structure is formed from the product of the second stage of degradation [15,16]. On the other hand, PEO decomposes by only a single degradation stage, beginning at 379 °C (T onset ) with T max at 401 °C.…”