Thermal Methods Flashcards
Refers to those techniques wherein a physical property of a substance or its reaction products is measured as a function of temperature
Thermal methods
Measures weight loss as a function of temperature in controlled environment
Thermogravimetric analaysis (TGA)
Calculates heat flow by measuring how much heat it takes to increase temp of samole compared to a ref material
Differential Scanning Calorimetry (DSC)
Phenomenon observed in the initial segments of many differential thermograms of polymers.
Glass Transition
Characteristic temp at which glassy amorphous polymers become flexible or rubber-like because of the onset of the concerted motion of large segments of the polymer molecules
Glass Transition Temperature
Widely used tool for generation of phaee diagrams, study of phaese transitions, and characterizing polymers
Differential Thermal Analysis (DTA)
Measures temperature difference between a sample and reference material
Differential Thermal Analysis (DTA)
Most often used thermal analysis method because of it’s speed, simplicity, and availability.
Differential Scanning Calorimetry (DSC)
____ is a a calorimetric method in which differencesin energy are measured. _____ the differences in temp is recorded
DTA, DSC
_____ is a quantitative technique while ____ is a qualitative technique
DSC, DTA
Plot of mass or mass percentage as a function of time is called __
Thermogram or thermal decomposition curve
How temp affects the weight of material
TGA identifies multiple points of weight loss, thus it can screen for additives, moisture, and filler content within the polymer.
Commonly used thermal methods to test the thermal stability in both solids and liquids
TGA
Understanding samples enthalpy as it moves from one state to another using DSC
DSC often used due to its speed, simplicity and availability.
Understanding how sample’s temperature rises bwhen subjected to heat using DTA
In DTA the substance and ref material are subjected to a controlled temp program
