Preparation and characterization of polymethacrylamide/halloysite composites

ABSTRACT Methacrylamide (MAA) including halloysite (H) with different contents was polymerized in aqueous medium with the in situ technique by using benzoyl peroxide as a radical initiator. Halloysite, polymethacrylamide (PMAA), and prepared composites were examined with X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and differential thermal analysis (DTA), and nitrogen adsorption/desorption (N₂‐AD) techniques. The XRD results showed that the crystal structure of halloysite unchanged by the formation of the composites, but completely transformed to the metahalloysite. The SEM images exhibited that the composites have a spongy and porous‐shaped morphology. The TEM view revealed that the halloysite particles distributed in the PMAA of both fiber bundle and exfoliated forms. Thermal analysis demonstrated the improved thermal stability of composites relative to the pure PMAA due to the incorporated halloysite. Furthermore, surface area, micro‐ and mesopore volume, and moisture retentions of the composites decreased with increasing PMAA content.