Modulated-temperature thermomechanical analysis of fibres

The application of modulated temperature programming to thermomechanical an alysis affords a method for measuring the 'true' thermal expansion coeffici ents of materials that deform irreversibly during normal TMA. This may aris e from creep under the applied load or changes in dimensions due to relaxat ion of orientation. Acrylic fibres made with various degrees of orientation shrink to different extents on heating but all show the same 'true' therma l expansion coefficients using this approach. The application of modulated temperature programming to Dynamic Mechanical Analysis is also discussed.