Thermal, dielectric and compressive properties of hollow glass microsphere filled epoxy-matrix composites

Abstract

Four types of hollow glass microspheres, having the density of 0.125–0.60 g/cm3, were filled into epoxy-matrix, and volume fraction of hollow glass microsphere was varied from 0% to 60%. The thermal, dielectric and compressive properties of the composites were investigated. The results show that the thermal conductivity, dielectric constant (Dk) and loss (Df) and compressive modulus and strength of the composites show decreased trend with increasing hollow glass microsphere content or decreasing hollow glass microsphere density, which indicates that the properties of the composites are mainly dependent on the characteristics of hollow glass microsphere. By comparing the experimental data and theoretical predictions, it is found that the properties of the composites, especially for thermal conductivity, are also related to the voids in epoxy-matrix. To conveniently predict thermal conductivity and Dk in the investigated materials system, theoretical models reported in the literature are analyzed and compared with the experimental data. Finally, suitable models are recommended. In addition, the thermal conductivity and dielectric properties of the composites were investigated as a function of testing temperature. This work indicates that thermal, dielectric and compressive properties of epoxy-matrix composites can be tailored by adjusting hollow glass microsphere content and density, which makes hollow glass microsphere filled composites a promising candidate in related fields.

Room temperature processable heat‐resistant epoxy‐oxazolidone‐based syntactic foams

“…In addition, the air space occupies a large volume of the composites, and this reduced the overall strength of the system. A crack will initiate in a porous composite at an oversized void or at the weakest microballoon when it is subjected to load, and then the subsequent failure occurs due to stress concentration resulting in crack propagation until it reaches the end of specimen wall, with fine thickening of the crushed layer due to accumulation of broken microspheres . Thus, as the volume percentage of glass microballoons increases, compressive strength and density of the syntactic foams decrease.…”

Investigation of thermal conductivity and dielectric properties of LDPE-matrix composites filled with hybrid filler of hollow glass microspheres and nitride particles

“…As an often used filler, hollow glass microsphere (HGM) consists of outer glass and inner inert gas, which results in lower D k and thus it can be used to modify the dielectric properties of the polymer-matrix composites [28][29][30][31][32][33]. However, it is obvious that the thermal conductivity of the composites decreases due to lower thermal conductivity of HGM if only HGM filler is filled into the composites [31][32][33][34][35]. In our previous study, nitride (AlN or BN) particle and HGM were simultaneously filled into epoxy matrix, and resultant composites had higher thermal conductivity as well as lower D k and D f than those of epoxy matrix [36].…”

The identification of effective thermal conductivity for fibrous reinforcement composite by inverse method

“…Some investigators believe that none of these theoretical models is truly complete because they suggest some difficult assumptions satisfied experimentally. Many other researchers are interested to determine conductivity by experimental works, 28,[30][31][32][33][34][35] but this alternative is seems to be costly and timetask. Alternatively, computer simulation has become a cost-effective tool.…”