Enhanced DSC Instrumentation Design and Characterization of Adhesives
Thermal analysis and rheology have played an essential role in the development of adhesives for a long time. Differential scanning calorimetry (DSC) in particular uses various methods to characterize melting and softening behavior, and quantify crosslinking reactions. By measuring the heat absorbed or evolved by a sample as it is heated (or cooled) under a controlled temperature and atmosphere, DSC is able to record changes in specific heat capacity and latent heat that indicate changes in amorphous and crystalline structures. While rheology can provide a more detailed analysis of the time-dependent mechanical properties of an adhesive, such as tack and shear strength1, DSC delivers a very quick snapshot of the adhesive system, especially the glass transition (Tg) region.
The DSC technique is not new, but its utility for many kinds of analysis has recently been greatly enhanced by TA Instruments' introduction of the Q Series line of DSCs incorporating TzeroT Technology (Figure 1). This development is not just another DSC cell with improved baseline stability, but in fact a new measurement principle with an additional sensor that together provide compensation for intrinsic instrument distortion of the DSC signal2. Because distortion has been virtually eliminated, it is now possible to measure specific-heat capacity directly in a single scan, and to achieve greater sensitivity and accuracy. Tzero Technology also reduces analysis time, especially for Modulated Temperature Differential Scanning Calorimetry (MDSCR)3.