Abstract
Polymerization of methyl methacrylate (MMA) was carried out in the presence of exfoliated graphite in water. Exfoliated graphite encapsulated with poly (methyl methacrylate) (PMMA) was obtained. The amount of PMMA in the encapsulated exfoliated graphite can be controlled by changing the ratio of the monomer to exfoliated graphite. SEM and TEM observation indicates that the exfoliated graphite is coated homogeneously by PMMA.
This encapsulated exfoliated graphite composite can be directly molded by hot press. The electric conductivity and the shielding effect for electromagnetic interference of this molded product were superior to those of the exfoliated graphite-PMMA composite made by mechanical mixing.
The microscopic observation of the cross section of the specimen shows that the difference of electric conductivity between the encapsulated exfoliated graphite-PMMA composite and the mechanically mixed exfoliated grapite-PMMA composite and the mechanically mixied exfoliated graphite-PMMA composite is due to the degree of dispersion of exfoliated graphite in polymer matrix, i.e., the exfoliated graphite in the encapsulated composite is homogeneously dispersed in comparison with that in the mechanically mixed composite.
