Amorphous graphite/polymethyl methacrylate composite microspheres: design, preparation, and performance study

Abstract

Amorphous graphite/polymethyl methacrylate (MAG/PMMA) composite microspheres were synthesized by suspension polymerization. It was found that the contact angle of amorphous graphite (AG) changed from 32.55° into 112.58° after modification by sodium(C16) alkylsulfonate, which showed that the surface of modified amorphous graphite (MAG) were hydrophobic. The modified AGs effectively improved the dispersion in monomer, which helped to improve the compatibility of amorphous graphite in the polymer. The experimental results showed that the thermal properties of the composites were improved effectively by increasing the loading amounts of MAGs, especially when the amount was 2.5 wt %. The compressive strength of MAG/PMMA composite microspheres with the same diameter (1 mm or 2 mm) was significantly 2 times higher than that of the pure PMMA crosslinked polymer microspheres. The specific surface area increased from 0.2347 m2·g−1 of pure PMMA to 3.4074 m2·g−1 when the amount of adding MAGs was 2.0 wt %. The N2 adsorption–desorption isotherms of pure PMMA and MAG/PMMA composite microspheres belonged to V type of IUPAC and H1 hysteresis loop, indicating that adsorption quantities were higher than that of PMMA with adding the MAGs.