Preparation, structure, and properties of poly(vinyl acetate-co-methyl methacrylate) nanocomposite microspheres with exfoliated montmorillonite through using two-stage in situ suspension polymerization

Abstract

Effective encapsulation of montmorillonite intermediate particles (I‐MMT) within poly (vinyl acetate‐co‐methyl methacrylate) (PVAMMA) copolymer by in situ suspension polymerization was performed. The I‐MMT encapsulation, layer exfoliation behavior, chemical composition, particle size distribution and thermostability of PVAMMA/I‐MMT nanocomposite microspheres were characterized by electron microscopies, X‐ray diffraction (XRD), laser particle analyzer, and thermogravimetric analysis (TGA). Swelling behaviors of the nanocomposite microspheres in various cationic salt solutions (NaCl and CaCl2) and anionic salt solution (NaCl and Na2SO4) were also investigated. Results showed that the properties of layer dispersion surface and expansion of these nanocomposite microspheres were well achieved. The synthetic yields of the nanocomposites decreased as the I‐MMT loading increased. These nanocomposite microspheres had an average size from 96.8 μm to 138.4 μm with narrow particle size distribution, loose, and porous surface morphology. XRD patterns clearly proved the exfoliation of MMT layers in the copolymer matrix, which was consistent with TEM analysis. These nanocomposite microspheres showed higher negative zeta potential and higher thermal stability than those of the copolymer microspheres, which was due to the layer exfoliations in encapsulated microspheres. These selected microspheres with 10 to 70 μm diameters provided effectively plugging in the micrometer‐sized core channels through deformation and migration process in plugging experiments, which made them be the candidate materials for modifying the porous reservoir to enhance oil recovery in petroleum engineering. POLYM. COMPOS., 35:1104–1116, 2014. © 2013 Society of Plastics Engineers

Montmorillonite Exfoliation in LLDPE and Factors Affecting Its Orientation: From Monolayer to Multi-Nano-Layer Polymer Films

“…Polymerization is then triggered around the MMT nanosheets. Another route is solution exfoliation [ 10 , 12 ], in which the MMT powder is dispersed in a solvent in which the polymer is soluble. Similar to the previous case, the solvent causes the MMT to swell and exfoliate, and the polymer chains surround the MMT nanosheets.…”

Synthesis of Polyurethane/TiO2 Hybrid with High Encapsulation Efficiency Using One‐Step Miniemulsion Polymerization for Methylene Blue Degradation and its Antibacterial Applications

“…Encapsulation technology has led to the development of several processes for the preparation of inorganic NPs with well‐defined structures. A variety of synthetic approaches, typically using heterophase polymerization methods, have been employed to create hybrid polymers in colloid systems, such as miniemulsions, [8,17–19] emulsions, [13] and dispersion polymerization [20–21] . Generally, the hybrid particle structure consists of a heterogeneous distribution of inorganic and organic NPs in a polymer matrix of different natures.…”

“…A variety of synthetic approaches, typically using heterophase polymerization methods, have been employed to create hybrid polymers in colloid systems, such as miniemulsions, [8,[17][18][19] emulsions, [13] and dispersion polymerization. [20][21] Generally, the hybrid particle structure consists of a heterogeneous distribution of inorganic and organic NPs in a polymer matrix of different natures. These hybrid colloids often consist of hydrophilic inorganic NPs and a hydrophobic polymer matrix for practical reasons.…”

Evaluation of a novel profile control agent for enhancing an oil‐recovery application

“…To achieve the high salt‐ and temperature‐resistance properties, efforts in nanocomposites have been made in recent decades; these studies have provided great progress on the profile modification technique . Montmorillonites (MMTs) were introduced to the system to increase the strength of the gel particle because of their intercalation properties; this enhanced the tolerance of the particles to the temperature and salinity, However, it is still challenging for the particles in reservoirs having temperatures above 100 °C and salt concentrations above 100,000 mg/L . Some composites have even shown a dramatic increase in the postdegradation gel viscosity; when nanoclay was added, however, they showed a temperature resistance of just 80 °C and a salt concentration of 10,000 mg/L …”