| Polyaniline (PANI) is a well known intrinsic conducting polymer(ICP), shows excellent electrical conductivity together with tunable electronic properties, reversible doping, good environmental stability, easy synthsis and low cost, makes polyaniline is the subject of extensive investigations for applications in electronics, industry and medicine. However, some potential applications have not yet to be exploited because of its poor processability, poor solubility and lack of mechanical properties. To improve physical properties, a number of attempts have been made to prepare blends or composite materials containing PANI. Poly (vinyl alcohols), PVA, was a kind of hydrophilic material which containing many hydroxyl groups. Meanwhile, PVA has been the main focus to be used as matrix because it is water soluble, good polarity, good mechanical strength, well film-forming, biodegradable and low toxic.In this paper, we chose PVA0588 as the polymer matrix, nucleophilic substitution as the reaction mechanism, and we used the abundant-OH groups in molecular chains of PVA which provide many active points of the whole reaction. A series of Poly(vinyl alcohol)/Polyaniline dispersion were prepared by graft copolymerization of aniline in Poly(vinyl alcohol) solution with epoxy chloropropane. Then influences on the properties of conductive composites by changing the content of ECIP or aniline were discussed. The results showed that PANI successfully grafted on PVA chains, formed comb-like polymer. It’s proved that ECIP was the key of the whole reaction because ECIP offered the active points for aniline to graft copolymerize. The lacking ECIP or excessive PANI would lead to the phase separation of the composites because of the self-polymerization of excess aniline. Due to the introduction of PANI, the PVA/PANI particles displayed different morphology. The uniform composite films showed excellent mechanical property and outstanding electrical conductivity. The maximum electrical conductivity can reach to 1.02S/cm.In order to improve the properties of PVA/PANI composites, we choose 3-chloro-2-hydroxy-propyl-trimethyl ammounium chloride (QA) as raw material, and prepared a series of cationic PVA/PANI composite materials. The FTIR spectroscopy, NMR results showed that cationic groups had been introduced into molecular chain successfully. The QA-PVA/PANI particles displayed relatively smaller and more uniform morphology than ECIP-PVA/PANI particles, especially when the content of QA is less than 30%. However, when further increased the content of QA, the situation changed. The more content of QA, the larger particle sizes, the less stable of the dispersions. The introduction of the quaternary ammonium cationic groups can improve the compatibility of PVA and PANI, so that QA-PVA/PANI composite films performed excellent mechanical properties, thermal stability and electrical conductivity.Finally, we coated the nanostructured PVA/PANI dispersions on natural fiber paper to prepared CF series and QCF series conductive paper, for the purpose of studying the applications of PVA/PANI composites. Then compare the properties of CF series and QCF series conductive paper with natural fiber paper. The results of the study are as follows:There were so many PANI particles adsorbed on the surface of the conductive papers that can form many conductive channels. And the number of PVA/PANI particles on QCFs was much more than on CFs. However, the adsorption quantity and electrical conductivity of QCFs was not increased with the content of QA. When the content of QA was 20%, we got the most adsorption quantity and the best electrical conductivity of conductive papers. It can be 9×10-3 S/cm. We could see continuous and homogeneous PVA/PANI composites adsorbed on the surface of natural fiber paper. Moreover, the PVA/PAN conductive papers had the better mechanical properties and thermal properties than NF. This kind of PVA/PANI conductive papers must have a promising application prospect in anti-electrostatic packaging field. |
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