glass transition temperature (Tg)

The Glass Transition Temperature (Tg) is the temperature at which a material, typically a polymer, transitions from a hard and brittle state to a softer, more flexible state. Below Tg, the material behaves like a rigid glass, unable to flow. As it heats past this temperature, the molecular structure becomes more mobile, allowing the material to deform. This concept is crucial in understanding the performance and durability of various materials used in everyday products, such as plastics, rubbers, and glasses, influencing their applications across industries.