Search

In this study, a novel functionalized graphene oxide(GO) sheet of polyaniline(PANI) was prepared by in situ polymerization of aniline. Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD) and scanning electron microscope (SEM) indicated the successful polymerization of aniline on GO tablets, and PANI was uniformly inserted into the GO lamellas that benefited the dispersion of PAGO. The anticorrosion properties of PAGO-PVC/EP coatings with different contents were analyzed and compared with PAGO-0 and the GO coatings. Electrochemical analysis showed that an appropriate amount of PAGO (0.5wt%) could significantly improve the long-term corrosion resistance of the coating. Its excellent corrosion resistance was attributed to two parts: (1) PAGO had good dispersion and could improve the barrier property of the coating to block H2O, O2 and electrolytes from penetrating to the steel substrate; (2) PANI with complete electrical activity could timely transfer the electrons lost from the base to the coating surface, and form a passivation film composed of Fe3O4 and Fe2O3 by induction. The barrier property of GO and the self-healing ability of PANI made PAGO-based PVC/EP coatings excellent in corrosion resistance. [ABSTRACT FROM AUTHOR]

Swelling properties of amphoteric polyacrylamide (AmPAM) dispersions were investigated by measurements of apparent viscosity and particle morphology. AmPAM dispersion was prepared by dispersion polymerization in aqueous solution of ammonium sulphate. Changes of particles during dispersion polymerisation of AmPAM were simulated and compared with anionic and cationic polyacrylamide (APAM and CPAM, respectively). Sample viscosity and particle morphology were obtained using a rotational viscometer and optical microscope. It was found that small molecules or ions enter and swell particles in the AmPAM dispersion when (NH)SO concentration decreases. Similarly, monomers, including acrylamide, acrylic acid, and methacrylatoethyl trimethyl ammonium chloride, have the same effects on the AmPAM dispersion but the effect degree is different. Swelling properties of the AmPAM dispersion were different from those of the APAM and CPAM dispersions due to their different ionic nature, type of stabiliser, media, etc. Particles in the APAM or CPAM dispersions were swelled less than those in the AmPAM dispersion. [ABSTRACT FROM AUTHOR]