Consistent glass transition temperature of epoxy resin by three different test methods on the same nanomechanical test instrument

Glass transition temperature (Tg) is a critical property of polymers that determines their service temperature. Various methods, such as differential thermal analysis (DTA), thermomechanical analysis (TMA), dynamic mechanical analysis (DMA), and thermal dilation analysis (TDA), are commonly used to measure Tg. Large discrepancies often arise due to differences in test conditions, sample sizes, Tg definition, and temperature calibration errors. These inconsistencies make it difficult for researchers to compare results and communicate effectively. To address this issue, an innovative approach by performing TDA, DMA, and TMA on the same nanomechanical test instrument was introduced. This approach measures the Tg of epoxy resin at microscale, eliminating errors from inter-instrument temperature discrepancies. Our results demonstrate that the Tg values obtained by different methods are practically the same when appropriate Tg definition, effective sample size and test conditions are applied. This approach will have a significant impact on polymer research.