Process intensification of encapsulation of functionalized CaCO3 nanoparticles using ultrasound assisted emulsion polymerization

The present work deals with the use of intensified processes based on the ultrasonic irradiations for the improvement of the process of encapsulation of inorganic nanoparticles into polymer during nanocomposite synthesis process. The cavitational effects produced due to the use of ultrasonic irradiations have been shown to enhance the dispersion of functional nano-inorganic particles into the monomer during polymerization process. The model system is based on the nanocomposite of poly(methyl methacrylate)/calcium carbonate (PMMA/CaCO3) which has been synthesized by ultrasound assisted semibatch emulsion polymerization. CaCO3 nanoparticles were pretreated with myristic acid in order to improve the compatibility of the monomer with the inorganic particles. TEM image of PMMA/CaCO3 composite particles with well-defined core–shell structure give direct evidence of encapsulation. Effect of encapsulation of CaCO3 particles on thermal properties has been evaluated using thermo-gravimetric methods and it has been observed that the nanocomposites have better thermal stability as compared to the PMMA.