Glass‐transition temperature determination by microhardness in norbornene‐ethylene copolymers

Vickers microhardness as a function of temperature was determined in a series of norbornene‐ethylene copolymers synthesized with a metallocene catalyst. The norbornene content in the samples ranges from 31 to 62 mol %, and all of them were found to be amorphous. The possibility of studying the glass‐transition temperature by plotting the microhardness‐temperature dependencies is discussed in addition to the limits and the reliability of the suggested method. Moreover, a linear dependency between microhardness at different temperatures and glass‐transition temperature was established. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3666–3671, 2003