Abstract:
Polymer Nanocomposites (PNC’s) have gained significant interest in the field
of polymer research due to their enhanced Physical, Thermomechanical, Mechanical,
and Electrical characteristics with respect to neat matrix. In the present study
Polycarbonate/Graphene nanocomposites were synthesized. Graphene was obtained
from two sources (industrial Graphene and Few layered Graphene) and then it was
dispersed in the polymer matrices by Solution mixing method in different ratios to
prepare PNC’s. These PNC’s then were characterized for physical, mechanical and
electrical properties using various techniques. SEM and XRD data confirmed a good
dispersion of both types of graphene in the polycarbonate matrix. Thermal studies of
the PNCs prepared showed that glass transition temperature of polycarbonate
nanocomposites was increased as compared to the neat polycarbonate and a maximum
of 15˚C increase in Tg was observed in case of PC/IG nanocomposites at 0.5%
loading of industrial graphene. Dielectric spectroscopy of the samples prepared
showed an improvement in dielectric properties like dielectric constant, dielectric loss
and dissipation factor of the polycarbonate after the inclusion of both Few Layer
Graphene and Industrial Graphene in low frequency region. In this regard a gradual
increase in dielectric values of the nanocomposites was observed as the graphene filler
contents were increased until a threshold value of the filler contents. These threshold
values for the aforementioned dielectric properties were 0.5% and 1% for Industrial
Graphene and Few Layer Graphene respectively. AC conductivity, however, remained
unchanged as compared to neat polycarbonate in a range of applied field frequency.
Mechanical testing showed a decline in the tensile strength and % elongation of the
nanocomposite samples as compared pure polycarbonate. Elastic modulus, however,
was increased up to 300MPa more than the pure polycarbonate 0.5% loading of
industrial graphene. Possible mechanisms and logical/theoretical reasons for these
effects on each characteristic have been prescribed in this work. Data analysis
concludes that, dielectric properties were better improved by inclusion of FLG as
compared to IG while thermal properties and Elastic modulus were better modified by
IG as compared to FLG inclusion in polycarbonate matrix.
