Heat Capacity, Thermal Conductivity and Pressure—Volume—Temperature of PLA

4 Heat Capacity, Thermal Conductivity and Pressure-Volume-Temperature of PLA 

Heat capacity, thermal conductivity and pressure-volume—temperature (PVT) are the macroscopic characteristics of polymers that are very important during the processing stage. Typical heat capacity determines the amount of heat required to bring the respective volume of PLA up to the final processing temperatures. Meanwhile, thermal conductivity and PVT can affect the rate of heat transfer and compressibility, which are important in determining the shrinkage of injection-molded products. 

Heat capacity characterizes the amount of heat required to change a substance s temperature by a given amount. It is very important to determine the preliminary amount of energy required to increase the temperature of a polymer up to the processing temperature. A comprehensive study on the heat capacity of PL A has been reported by Pyda et al. (2004). The data shown in Table 3.7, as disclosed by Pyda et al. (2004), is the most comprehensive to date and includes the temperature range 5—600 K. 

The thermal conductivity of PLA is summarized in Table 3.8. As can be seen, the thermal conductivity of PLA increases almost in relation to the elevation of temperature. Thermal conductivity of a polymer has a great influence when dealing with heat removal during the cooling process for injection-molded articles. Sufficient and controlled heat removal can reduce the possibility of warping. 

Where the detail of two-domain tait PVT equation is explained as  

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