Glass transition temperature (Tg) is a very important concept when it comes to properties of materials and their design. Tg of a material is temperature at which it changes from a hard brittle state to a rubbery or liquid-like state. Understanding Tg of a material is critical for many reasons, including its effect on performance, cost and durability of materials used in a wide variety of products.

The glass transition temperature is temperature at which a material changes from a brittle solid to a rubbery or liquid-like state. Depending on material, this transition can be quite abrupt and occur over a narrow temperature range. In some materials, transition to rubber-like state is gradual and happens over a much wider temperature range. In either case, it is important to understand when this transition occurs in order to design materials for a particular application.

The Tg of a material affects its performance in many ways. For instance, Tg of a material can affect its thermal stability; materials with low Tg are more sensitive to temperature changes and become soft or even liquid when exposed to higher temperatures. High Tg materials, on other hand, remain solid over a wider range of temperatures. Similarly, materials with low Tg are generally more prone to creep, where they deform or flow over time due to continuous application of stress. In contrast, materials with higher Tg are less susceptible to creep.

In addition to affecting performance, glass transition temperature is important for cost and durability of a material. Materials with low Tg generally require less energy to process, which can lead to lower costs. However, because of their lower Tg, these materials are not as durable as those with higher Tg and are more likely to fail over time. This can lead to higher maintenance and replacement costs in long run.

Understanding glass transition temperature of a material is essential for engineers, designers and other professionals who work with materials. It helps them understand how material will react to various temperatures and stresses, as well as how cost-effective and durable material is likely to be. With right knowledge, professionals can make informed decisions about which materials to use in a given application in order to ensure best possible performance and cost-effectiveness.