Preparation and characterization of PVAc-MMT-DOAB

Polyvinyl acetate (PVAc) is considered to be a type of environmental friendly adhesive, and montmorillonite (MMT) is a cheap and accessible natural nanomineral. MMT was first organically activated by dioctadecyl dimethyl ammonium bromide (DOAB). The intercalated nanocomposite of MMT-DOAB was added during the synthesis of PVAc in conventional laboratory conditions. The PVAc-MMT-DOAB was mainly studied by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, static tension, and the rheology was also investigated by the power-law function equation and the Cross—Williamson model viscous equation. The exfoliated nanocomposite of PVAc-MMT-DOAB could be obtained. Linear macromolecular chains of PVAc were formed in the layers of MMT-DOAB. MMT-DOAB was exfoliated into nanoparticles of layers or sheets, randomly dispersed in the matrix of PVAc. The particle diameter of MMT-DOAB ranged from 25 to 75 nm, they randomly dispersed with PVAc particles. In addition, the smaller MMT-DOAB particles were adsorbed around the bigger PVAc particles; they formed the ‘strawberry’ structure. PVAc and PVAc-MMT-DOAB were pseudo-plastic non-Newtonian fluids and they all possessed the normal stress effect (or Weissenberg effect), that was the pole-climbing phenomenon. The reasonable addition of MMT-DOAB in polymerization was found to be not more than 2.0 wt.% of VAc.