Effects of highly exfoliated montmorillonite layers on the properties of clay reinforced terpolymer nanocomposite plugging microspheres

Abstract

In this study, exfoliated montmorillonite (MMT) nanolayers were successfully encapsulated in acrylamide/acrylic acid/2acrylamido-2-methylpropanesulfonic acid (AM/AA/AMPS) terpolymer microspheres by in situ inverse suspension polymerization with the aid of the organic intercalation modification and the lateral groups of terpolymer chains. The introduction of well-dispersed MMT nanolayers reveals a significant enhancement of the comprehensive properties of these nanocomposite microspheres, such as the viscoelasticity, thermal stability, and plugging ability. Compared with the pure terpolymer, the elastic modulus (G 0 ) of terpolymer/2.0 wt % O-MMT nanocomposites is 4.30 times higher and the decomposition temperature of these nanocomposites increases by 40 8C. The plugging rate reaches as high as 86.6%. Besides, surface morphology, swelling degree, and wetting behavior can be effectively tuned by varying the content of exfoliated MMT. The wetting angle increases to 82.0 8 which is suitable for modifying the formation channels. These selected nanocomposite microspheres can effectively enter and plug the high permeable microchannels.Polymer nanocomposites containing inorganic nanoparticles are gathering increasing attention owing to their remarkable improvements in mechanical and thermal properties compared with pristine polymer. 5,6 Montmorillonite (MMT) is one of the most widely used inorganic layered silicates because the lamellar elements exhibit high in-plane strength, stiffness, and a high aspect ratio. 7,8 Strong interfacial interactions between the dispersed layers and the polymer matrix can significantly enhance the mechanical, thermal and barrier properties of the virgin polymer. 9 Moreover, the dispersed MMT layers can also exhibit catalytic, nucleation, and crosslinking effects that adjust the morphology and function of the polymers. [10][11][12] The properties of the obtained polymer/ MMT nanocomposites depend on the level of MMT platelet delamination and the MMT dispersion in the polymer matrices. 13 Well-dispersed MMT layers, especially exfoliated layers, cannot be easily achieved due to their preference for face-to-face stacking in agglomerated tactoids during polymerization. 14,15 Presently, some

The influence of organically intercalated montmorillonites on the interfacial tension and structure of oil-in-water nanoemulsions

“…The organically intercalated montmorillonite (OMt) suspension was prepared according to a previously reported protocol. 24,25 In a three-necked ask, 3.0 g of pristine montmorillonite (Na-MMT) was dispersed in 100 mL of deionized water for 30 min. The intercalating agent G16-2-16 (0.4 g, equal to $0.27 CEC) was dissolved in 25 mL of deionized water before its addition to a threenecked ask and then stirred for 8 h at 80 C. To maintain the amphiphilicity of OMt and disperse it well in water, the amount of the cationic intercalant was set at 0.2 CEC; aer completion of the cation exchange reaction, a part of the OMt suspension was ltered and dried under vacuum for XRD measurement; the remaining OMt suspension sample (solid content ¼ 2.85% w/v) was sealed and stored for emulsion preparation.…”

Enhancement of the physical and mechanical properties of wood using a novel organo-montmorillonite/hyperbranched polyacrylate emulsion

“…However, there were no obvious diffraction peaks found for OMMT/HBPA at 2θ = 2-10°. From literature, it was observed that if the MMT was completely exfoliated into individual and collapsed silicate layers, the regular crystalline structure cannot be found from the XRD patterns ( Ji et al 2017;Osman et al 2017;Xu et al 2019a). From Figure 1a, it was observed that there were some small peaks at 25°, 32°, and 34°.…”

Preparation and properties of amphiphilic hydrophobically associative polymer/ montmorillonite nanocomposites

“…However, natural Na-MMT is hydrophilic because of the presence of Na + and K + ions between its layers. Therefore, in order to increase the compatibility of MMT platelets with hydrophobic polymer bulk, the original MMT needs to carry out organic pre-modification by cation exchange technology [34,38]. Many previous studies have indicated the organic MMT is easier for achieving homogeneous dispersion and exfoliation in the polymer matrix [36,39].…”