Preparation And Anticorrosion Properties Study Of Poly(2,3-dimethylaniline)/Attapulgite Nanocomposites

Polyaniline has become one of the most conductive polymeric materials of widely application because of its excellent environmental stability, particular doping mechanism and excellent electrochemistry property. Recently, polyaniline(PANI) has become a novel anticorrosion coating materials. Although PANI has good corrosion protection properties, its poor solubility and processability due to its high aromatic nature and intermolecular hydrogen bonding between amine groups and imine groups of the adjacent chains have strongly limited its practical applications. Poly(2,3-dimethylaniline)(P(2,3-DMA)), which was substituted by two methyl groups on the same side of benzene ring as one of main polyaniline derivatives, can effectively solve above problems. In addition, it is possible to avoid the occurrence of side-reactions of substitution position of benzene ring, and favorable for the formation of macromolecular conjugated system. Thus, it has a great potential of commercial application in the field of metallic protection.Nanocomposites have better pergormace than the conventional composites with the same composition due to nanosize effect, large specific surface area and strong interfacial interaction. Attapulgite is a natural mineral clay with nano-fiber structure. It has been reported that organically modified silicates can effectively decreased interaction between chains and crystallinity, and improve the thermal, mechanical and interface stability properties of polymer. Organic-attapulgite has been introduced into the polymeric coatings to effectively increase the length of the diffusion pathways for oxygen and corrosion irons as well as decrease the permeability of coating. It has also been reported that introcudtion of p-phenylenediamine is in favor of synthesis polyaniline of derivatives nanofibers. Therefore, we attempt to prepare and explore the performance of P(2,3-DMA)/organic-attapulgite(P(2,3-DMA)/APTES-ATP) nanocomposites and P(2,3-DMA) nanofibers.In this paper, P(2,3-DMA)/APTES-ATP nanocomposite was prepared via in situ polymerization. The concentration of APS, the reaction time, the reaction temperature on the Tafel curve, EIS curve and yield of the nanocomposite were discussed. The as-prepared materials were characterized by means of XRD, FTIR, SEM,TEM and TGA-DTA, and the anticorrosion performance of the coating containing the nanocomposite on Q235 steel samples was estimated by a series of electrochemical measurements in 3.5 % Na Cl solution. Moreover, P(2,3-DMA)/nano attapulgite(PAF) nancomposite has been successfully synthesized by in situ emulsion polymerization in the presence of organic-kaolinite with DBSA and APS as emulsifier and oxidant, respectively. The corrosion protection effect of PAF materials in comparison to P(2,3-DMA) was demonstrated by a series of electrochemical measurements in 3.5 % Na Cl electrolyte. The effect of clay content on the PAF corrosion protect properties was investigated. In addition, we also have studied that compare the anticorrosion performance of P(2,3-DMA) nanofiber in comparison to poly(2,3-dimethylaniline) prepared without adding p-phenylenediamine(C-P(2,3-DMA)) in 3.5 % Na Cl electrolyte.The results showed that the P(2,3-DMA)/APTES-ATP nanocomposite has been successfully prepared by effectively dispersing the organic- attapulgite in P(2,3-DMA) matrix via in situ polymerization. The nanocomposite with the best properties when the mass ratio of organic-attapulgite to 2,3-DMA was 20:80, the mole ratio of APS to 2,3-DMA is 2:1, the mole ratio of HCl to 2,3-DMA is 1, the reaction time is 10 hours and the reaction temperature is 30。C. The XRD, FTIR, SEM and TEM showed that P(2,3-DMA)/APTES-ATP has a Core(APTES-ATP)-shell(P(2,3-DMA)) nanofibers structure. TGA-DTA curves showed that the incorporation of APTES-ATP with polymer resulted in an increase in thermal stability with respect to the P(2,3-DMA).The P(2,3-DMA)/APTES-ATP nanocomposite containing coating was found to offer excellent corrosion resistance than that of P(2,3-DMA). The result indicated that the nanocomposite increased the tortousity of the diffusion pathway of O2 and corrosion ions. P(2,3-DMA)/attapulgite nanocomposite based different system can be considered a potential coating material for corrosion protection of metal.The P(2,3-DMA) nanofiber containing coating has a better anticorrosion performance for Q235 steel compared that of C-P(2,3-DMA). The result showed that the morphology could be responsible for better anti-corrosion performances.