EVALUATION OF THE AREA UNDER LINEAR LOSS MODULUS-TEMPERATURE CURVES

The area under the linear loss modulus-temperature curves, LA, has been shown to be related to the chemical composition of the material. In addition, it can be significantly affected by morphology in multicomponent polymer systems. To characterize LA quantitatively, base-line corrections for instrumental contributions to LA were evaluated by several different methods and the results compared. In some instances, the calculation method affects only the LA magnitude, while general trends are unchanged; whereas in others, qualitative differences also become important. Not all of the methods described can be utilized universally. However, a straight-line-type of base line, similar to that which is used in infrared spectroscopy and differential scanning calorimetry, provides a widely applicable means of quantifying the loss area.