The glass transition temperature (

T

g

) is an important concept in polymer physics

marking the transition from the mobile state to the frozen state of polymer chain segments. It also serves as a crucial indicator for measuring the operating temperature of non-crystalline polymers. The dilatometry method for determining the

T

g

of polymers is helpful for students’ deepened understanding of the glass transition and the “free volume theory”. However

experimental failures are often encountered during the teaching process. Based on the experimental data

this article analyzed the two key issues that affect the experiment

both objectively and subjectively

and proposed different measures to improve the success rate of the experiment when using glycerol and ethylene glycol as filling reagents

respectively. This article aims to provide a reference for teac

hers and students in the major of the polymer materials and engineering.