This paper focuses on the development of polyvinylidene fluoride microfoam by implementing a chemical blowing agent through a continuous process. The objective was to investigate the effects caused by varying concentrations of chemical blowing agent, the use of a master batch as formulation variables, and variation of die temperature on the properties of polyvinylidene fluoride foam produced continuously. By using a 10% master batch formulation (contains 2% chemical blowing agent in final product), the cell density was increased while the cell size and foam density were decreased; the average cell size, cell density, and void fraction were found to be 50 μm, 7.7 × 10⁶ cells/cm³, and 33%, respectively. This is due to the increased cell density primarily due to the increased nucleation sites. At a lower chemical blowing agent, concentration of 1%, the die temperature was varied over a range of 125-145 °C, as this is approximately the melting point of the polyvinylidene fluoride. Decreasing the die temperature from 135 °C to 130 °C caused the cell density to increase and cell size to decrease, while void fraction decreased from 58% to 39%. This is due to the loss of melt strength upon increasing the temperature of the melt PVDF as it exits the die.

Graphene has exceptionally high surface area, mechanical properties, electrical conductivity, thermal conductivity, and gas-barrier performance, thus it is considered as an ideal multifunctional filler for rubbers. However, harnessing these properties in rubber nanocomposites requires us to carefully tailor the dispersion state of graphene, the vulcanization kinetics, the interfacial interaction and so on. This review summarized our recent works on how to disperse graphene homogeneously in rubber matrix, what influence of graphene or graphene oxide on the vulcanization behavior of the rubber nanocomposites, how to design a compact filler network in the rubber matrix, and how to engineer a strong interfacial interaction between graphene and rubber. These fundamental researches give us some thumb rules to develop graphene/rubber nanocomposites with significantly improved mechanical properties, gas-barrier performance, thermal stability, electric conductivity, antioxidation ability as well as some functionalities.

To explore a feasible strategy for improving the dielectric properties of carbon black (CB)/epoxy composites, CB@TiO₂ core-shell particles and CB-SiO₂ hybrid particles were prepared and incorporated into epoxy. The microstructures of CB, CB@TiO₂, and CB-SiO₂ particles, as well as the dielectric properties of their epoxy-based composites were investigated. The results showed that the composites containing CB-SiO₂ hybrid particles possessed a higher dielectric constant than the ones containing pristine CB. The dielectric constant of the composite with 20.0 vol% CB-SiO₂ reached 52.68 (1 kHz), which was ca. 4 times greater than that of the one containing 20.0 vol% pristine CB. Meanwhile, the composites containing CB@TiO₂ core-shell particles exhibited suppressed values of dielectric loss. The permittivity of the composite with 20.0 vol% CB@TiO₂ reached 19.52 (1 kHz), while its dielectric loss remained low (0.047 at 1 kHz). These results indicated that the dielectric properties of epoxy composites could be enhanced with the introduction of modified fillers.