Physical and mechanical properties of nanocomposite barrier film containing encapsulated nanoclay

Abstract

Waterborne poly(styrene-co-butyl acrylate) was prepared via miniemulsion polymerization in which nanoclay (Cloisite V R 30B, modified natural MMT) in different concentrations was encapsulated. Scanning electron microscopy, X-ray diffraction, and transmission electron microscopy confirmed the encapsulation and intercalatedexfoliated structure of Cloisite V R 30B within poly(styrene-cobutyl acrylate). The effect of nanoclay content on water vapor permeability, water uptake, oxygen permeability, thermal, and mechanical properties of thin films containing 1.5, 2.56, 3.5, and 5.3 wt % encapsulated Cloisite V R 30B in poly(styreneco-butyl acrylate) was investigated. The presence of encapsu-lated Cloisite V R 30B within the polymer matrix improved tensile strength, Young's modulus, and toughness of the nanocomposites depending on the nanoclay content. Water vapor transmission rate, oxygen barrier properties, and thermal stability were also improved. The results indicated that the incorporation of Cloisite V R 30B in the form of encapsulated platelets improved physicomechanical properties of the nanoclay-polymer composite barrier films.

Gas barrier properties of polymer/clay nanocomposites

“…They identied that improved barrier properties of the polymer/clay nanocomposites was primarily due to an increase in the degree of crystallinity of the polymer. 175 They found that the gas barrier properties of NR composites with SMK and precipitated silica were much higher than those of NR/ precipitated silica composites and NR/SMK.…”

Ultrasonication Technique: A Method for Dispersing Nanoclay in Wood Adhesives

“…Past research has shown that there is a direct linkage between properties of nanocomposites and quality of nanoclay dispersion [52][53][54][55][56][57]. In fact, the extent of improvement, as result of adding nanoclay, cannot be solely proportional to nanoclay loading because of difficulty in obtaining good dispersion at high loading.…”

Polymer Encapsulation of Single Clay Platelets by Emulsion Polymerization Approaches, Thermodynamic, and Kinetic Factors

“…As in polymer–polymer core shell particle formation, the interplay of thermodynamic and kinetic factors is also operating in clay encapsulation through (mini)emulsion polymerization. Looking from the starting point of miniemulsion polymerization, thermodynamically the clay has to be modified hydrophobically to make it miscible with the monomer initially . But the interfacial tensions change during the polymerization and the resulting morphology can still be armored latex particles.…”

“…Looking from the starting point of miniemulsion polymerization, thermodynamically the clay has to be modified hydrophobically to make it miscible with the monomer initially. [12][13][14][15][16][17][24][25][26][27][28][29][30][31] But the interfacial tensions change during the polymerization and the resulting morphology can still be armored latex particles. An interesting example is given by Chakrabary and Singha [25] where the use of neutral functional monomer, in combination with a fluorinated acrylate in miniemulsion polymerization, led to encapsulated Cloisite hybrid latex particles (multiple clay platelets per particle) whereas the use of a positively charged functional monomer led to armored morphology.…”

“…[21] Also heating up particles for a longer time can show a change in morphology toward the equilibrium morphology, as shown in Figure 3. [21] The use of the different encapsulated morphologies in films has shown improvement of mechanical properties, [26,27] water vapor, and oxygen barrier properties [26,33] and thermal stability. [29,33] The ultimate film morphology where all the encapsulated (cornflake) clay platelets are strongly oriented parallel to the film has not been achieved so far.…”