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Search Results for: polymer composites

Total Search Results Found: 149

Preparation and properties of carbon nanotube/binary-polymer composites with a double-segregated structure

Conductive polymer composites (CPCs) contain high concentrations of carbon nanotubes (CNTs) to maximize electrical conductivity. However, high nanoparticle concentrations degrade other important properties of CPCs. This study produced CPCs using ultrahigh molecular weight polyethylene (UHMWPE) fillers in place of CNTs in an attempt to maintain important physical and mechanical properties. A thermal analyzer measured the thermal conductivity of the CPC samples using the transient plane source (TPS) method. Results showed that the altered CPCs maintained the desired levels of electrical conductivity, but thermal conductivity levels did not meet the theoretical expectations, likely because UHMWPEs have a higher porosity than CNTs.

Thermal conductivity and dynamic mechanical property of glycidyl methacrylate-grafted multiwalled carbon nanotube/epoxy composites 

The purpose of this this study was to graft polymer chains onto the surface of carbon nanotubes (CNTs) to examine the morphology and thermal properties of the epoxy composites in comparison to multiwalled carbon nanotubes (MWCNTs). A thermal analyzer measured the thermal conductivity of the nanocomposites using the transient plane source (TPS) technique. Results showed that the addition of Glycidyl methacrylate (GMA) to the MWCNTs/epoxy composites significantly enhanced thermal conductivity compared to the pristine MWCNTs/epoxy composites.

Electrical and thermal conductivities of multiwalled carbon nanotubes-reinforced high performance polymer nanocomposites 

Multiwalled carbon nanotubes (MWCNT) have applications in the aeronautic industry. This study examined how the concentration of MWCNT affects the electrical and thermal conductivities of nanocomposites. A thermal analyzer (TPS) measured the thermal properties of the nanocomposites using the transient plane source (TPS) technique. Results showed that thermal conductivity of the samples increased with MWCNT concentration and temperature, but the phenoxy-MWCNT nanocomposites had higher thermal properties than the PES-MWCNT nanocomposites.

Thermal conductivity models for single and multiple filler carbon/liquid crystal polymer composites 

Adding conductive fillers to polymer resins improves the thermal conductivity of the polymers. In this study, Thermocarb TC-300 synthetic graphite and Fortafil 243 carbon fiber were added to Vectra A950RX liquid crystal polymer (LCP) to produce anisotropic single and multiple filler composites. A Thermal Constants Analyzer measured the thermal conductivity of the composites using the transient plane source (TPS) technique. The formulations that contained Thermocarb fillers had higher in- and through-plane thermal conductivities than those containing Fortafil, which was likely due to the higher thermal conductivity of the synthetic graphite particles. The theoretical models that were computed showed good agreement with the experimental results.

Thermal conductivity measurement

The transient technique is the commercial method used to test the thermal conductivity, thermal diffusivity, and specific heat of solids. With the instrument, a double spiral nickel sensor is sandwiched between two homogenous samples, and as the sensor pulses electrical currents through the sample, it simultaneously measures how long it takes for the temperature of the sample to increase. This method is typically used on glasses, insulating materials, and polymer composites.