FABRICATION AND CHARACTERIZATION OF MWCNT/THERMOPLASTIC MICROSPHERE NANOCOMPOSITE FOAMS

Abstract

A novel sonochemical method is developed to coat multi-walled carbon nanotubes (MWCNTs) on expandable thermoplastic (acrylonitrile and methylacrylonitrile polymer) microspheres (Expancel). These polymeric thermoplastic microspheres were further fabricated in a form of foam panels using a compression molding technique. The test coupons were cut precisely from the as-prepared panels and characterized by scanning electron microscopy (SEM), X-ray diffraction, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The SEM studies have shown that the MWCNTs are well dispersed over the entire volume of the matrix with minimal agglomeration. The foam cell structures are well-ordered, spherical in shape, and uniform in size. The TGA and DSC analyses indicate that the nanocomposite foam samples are thermally more stable than the corresponding neat foam samples. The compression tests have been carried out for both nanocomposite and neat foam samples. These test results show a significant increase in compressive strength and modulus for nanocomposite foam samples as compared to the neat foam samples. These enhancements in compressive properties have been observed repeatedly for multiple batches. The details of synthesis procedure, thermal and mechanical characterization are presented in this paper.