Polycarbonate thermal conductivity

Recall from the beginning of the chapter that a related quantity to the thermal conductivity is the thermal diffusivity, a, which is defined as k/pCp, where k is the thermal conductivity, p is the density and Cp is the heat capacity at constant pressure per unit mass, or specific heat. Below are these thermal properties for polycarbonate. 

Person 2 Determine the thermal conductivity and heat capacity for polycarbonate at 350°C from the plots. 

Determining the effect of viscous dissipation in the metering section of a single screw extruder. Consider a 60 mm diameter extruder with a4 mm channel depth and a screw speed of 60 rpm. The melt used in this extrusion system is a polycarbonate with a viscosity of 100 Pa-s, a thermal conductivity of 0.2 W/m/K and a heater temperature of 300°C. To assess the effect of viscous heating we can choose a temperature difference, AT of 30K. This simply means that the heater temperature is 30K above the melting temperature of the polymer. For this system, the Brinkman number becomes... 

It is demonstrated that when the NS concentration in the material decreases, thermal capacity goes up which is confirmed by the results of previous investigations. Thermal conductivity decline, when the NS concentration decreases, is apparently caused by the material defectiveness When Cu/C nanocomposites are introduced into the modified material, the NS can be considered as the generator of molecules excitation, which results in wave process in the material. It is found that polycarbonate modification with metal/carbon containing nanocomposites results in the changes in polycarbonate structure influencing its optical and thermal-physical properties. 

Fig. 3.3-tr6 Polycarbonate, PC creep modulus versus time Table 3.3-19 Polycarbonate, PC heat capacity and thermal conductivity Temperature r (°C) -200 -150 -100 -50 0... 

Another study pointed out the effects of multiple carbon fillers on the electrical and thermal conductivity of polycarbonate-based resins (King et al. 2012). Three different carbon fillers (carbon black [CB], carbon nanotubes [CNTs], and exfoliated graphite nanoplatelets [GNPs]) were analyzed via three different combinations of two different fillers (CB/CNT, CB/GNP, and CNT/GNP). In the case of the single fillers, a statistically significant increase was noticed at the 95% confidence level in composite electrical and thermal conduction. But too many filler interactions statistically impacted the composite electrical and thermal conductivity. 

King Julia A., Via Michael D., Mils Owens R, Alpers Daniel S., Sutherland John W, and Bogucki Gregg R. Effects of multiple carbon fillers on the electrical and thermal conductivity and tensile and flexural modulus of polycarbonate-based resins. J. Compos. Mater. 46 no. 3 (2012) 331-350. 

Table3.3-19 Polycarbonate, PC heat capacity and thermal conductivity...

Thermal Conductivity and Mechanical Properties of Wood Sawdust/Polycarbonate Composites... 

In the literature, several polymers have been used as absorber in flat-plate collectors. P. T. Tsilingiriss reported upon the use of the groups of polyolefin and EDPM, to overcome the undesirable effects of the poor thermal conductivity, he had exploited the design of the solar collector [4]. Polycarbonate selectively coated has been used as solar absorber plate double walled, by A. I. Kudish et al [5]. In another case, K. Sopian had developed a solar collector system using black fibreglass reinforced polyester (GFRP) [6]. 

THERMAL CONDUCTIVITY AND MECHANICAL PROPERTIES OF WOOD SAWDUST/ POLYCARBONATE COMPOSITES... 

A number of examples of reinforced or filled polymer systems are shown in Table 6. As a general rule, as the thermal conductivity or the amount of the non-polymeric phase increases, so does the thermal conductivity of the composite. Examples listed in Table 6 include glass-reinforced polycarbonate and pol3Kethylene terephthalate), and mica-filled epoxy resins. On the other hand, plasticizers... 

FIGURE 5.6 Coefficient of thermal conductivity, heat capacity, thermal diffusivity, and density for polycarbonate, a glassy polymer. (Reprinted with permission of the publisher from Tadmor and Gogos, 1979, p. 132.)... 

In a typical microfluidic setting, the most power absorbing material is the liquid sample in the microchannels. The common materials for microfluidic chips are glass, quartz, and thermal plastics such as polydimethylsiloxane (PDMS), poly(methyl methacrylate) (PMMA), and polycarbonate, which usually have very small absorption as compared to liquid materials. The absorption of the liquid medium increases with its ionic content which increases the conductivity and with the operating frequency. Take water as an example. 

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