The Studies on the Thermophysical Properties of Binary Systems of Neopentylglycol and the Derives

Abstract

Specific capacity and thermal conductivity are two very important physical quantities that characterize the heat performance of heat storage material. This paper measured the specific capacities and thermal conductivities of binary systems formed by NPG、TRIS and PE in the temperature range from 30oC to 70 oC and analyzed the experimental results from the point of view of crystal vibration. Hydrogen bonds exert great influence on the thermophysical properties of the binary systems. Although the components are only simply blended, substitutional impurity defects are incurred. As a result hydrogen bond will be affected in a complex way. There is no uniform trend between the value of x and specific capacity. Because of the influence of structure defect, specific capacity and phonon speed which all change with the strength of hydrogen bond, the relationship between thermal conductivity and the value of x is non-linear too. Because 40oC is near the phase transition temperature of NPGxTRIS1-x (x=0.618), its specific capacity at 40oC decreases and thermal conductivity increases. Because hydrogen bond changes with temperature, specific capacity of PExTRIS1-x (x=0.618) rises. Since 60oC is near the phase transition temperature, its specific capacity at 60oC falls. PExTRIS1-x (x=0.618) shows smaller thermal conductivities at temperatures higher than 30oC. This is because the hydrogen bonds become weaker with temperature. Blending impurities possessing longer mean free path with polyalcohol can change the thermal conductivity.