DSC理论与应用.ppt

DPC Dual Sample DSC Differential Photocalorimetry (DPC) : sample is exposed to UV/Vis radiation Dual Sample DSC: Allows two samples to be ran simultaneously 2920 Only 2910 2920 Q-Series Photocalorimetry Accessory (PCA) The Q-Series Photocalorimetry Accessory (PCA) was developed to deliver a UV/Visible light source to a sample while performing a DSC experiment These experiments measure the heat released by a material as it goes thru a cross-linking reaction due to exposure with the UV/Visible light in a temperature controlled environment PCA Equipment PCA Equipment * * After an equilibrate at 200 oC method segment, the isothermal temperature is stable to within 0.04 oC during the first 5 minutes and is then stable to within 0.01 oC for the remaining 95 minutes. * After an equilibrate at 200 oC method segment, the isothermal temperature is stable to within 0.04 oC during the first 5 minutes and is then stable to within 0.01 oC for the remaining 95 minutes. * After an equilibrate at 200 oC method segment, the isothermal temperature is stable to within 0.04 oC during the first 5 minutes and is then stable to within 0.01 oC for the remaining 95 minutes. * After an equilibrate at 200 oC method segment, the isothermal temperature is stable to within 0.04 oC during the first 5 minutes and is then stable to within 0.01 oC for the remaining 95 minutes. * After an equilibrate at 200 oC method segment, the isothermal temperature is stable to within 0.04 oC during the first 5 minutes and is then stable to within 0.01 oC for the remaining 95 minutes. Photo-cured Thermoset Photo-cured Thermoset Examples Dealing with Heat Capacity Effect of Side Chains on Cp Polymer Side Chain Cp (J/g/°C) PE -H 2.763 PP -CH 2.752 PS -Ph 2.139 As the steric bulk of the side chain increases, molecular mobility decreases resulting in lower specific heat. B. Wunderlich, ATHAS Cp Data Bank, 1985. Effect of Polymer Backbone on Cp # of Methylenes Cp (J/g/°C) 1 0.6226 2 0.6918 3 0.7088 4 0.7597 8 0.7