Engineering English
Glass Transition Temperature
Manufacturing Engineering · Chemical Engineering · Materials Engineering · Last updated: July 30, 2026 · How this entry was written
Definition: The glass transition temperature (Tg) is the temperature at which an amorphous polymer transitions from a hard, glassy state to a softer, rubbery state. It is a critical thermal property that affects mechanical behavior and processing conditions.
Example in context
“The glass transition temperature of the epoxy matrix was measured at 120°C, ensuring the composite maintains stiffness below that limit.”
“Epoksi matrisin cam geçiş sıcaklığı 120°C olarak ölçülmüştür, bu da kompozitin bu sınırın altında sertliğini korumasını sağlar.”
Where engineers use it
Glass transition temperature is a fundamental parameter in material selection for composites and plastics. Engineers use it to define the maximum service temperature of a polymer, guide curing cycles, and predict creep behavior under load.
Synonyms: Tg, glass transition point
Antonyms: melting point
In Chemical Engineering
The temperature at which an amorphous polymer transitions from a hard, glassy state to a more flexible, rubbery state.
“The glass transition temperature of the polycarbonate sample was measured using differential scanning calorimetry.”
In Materials Engineering
The glass transition temperature is the temperature at which an amorphous polymer or glass transitions from a hard, brittle state to a softer, rubbery state. It is a key property for polymers and composites that determines their service temperature range.
“The epoxy matrix has a glass transition temperature of 180°C, allowing the composite to be used in high-temperature aerospace applications.”
Practice: can you use “Glass Transition Temperature” at work?
A design engineer needs to choose between two amorphous thermoplastics for a structural bracket exposed to 80°C. One has a Tg of 95°C, the other 110°C. Describe the implications of each choice on performance.
Show a model answer
“Why must the glass transition temperature be considered when selecting a plastic for a high-temperature application?”
“Glass Transition Temperature” in 21 languages
| English | Glass Transition Temperature |
|---|---|
| Turkish | cam geçiş sıcaklığı |
| French | température de transition vitreuse |
| German | Glasübergangstemperatur |
| Spanish | temperatura de transición vítrea |
| Chinese | 玻璃化转变温度 |
| Arabic | درجة حرارة التحول الزجاجي |
| Portuguese | temperatura de transição vítrea |
| Russian | температура стеклования |
| Japanese | ガラス転移温度 |
| Italian | temperatura di transizione vetrosa |
| Vietnamese | nhiệt độ chuyển thủy tinh |
| Hindi | कांच संक्रमण तापमान |
| Thai | อุณหภูมิเปลี่ยนสถานะคล้ายแก้ว |
| Indonesian | suhu transisi kaca |
| Korean | 유리 전이 온도 |
| Bengali | কাঁচ স্থানান্তর তাপমাত্রা |
| Dutch | glasovergangstemperatuur |
| Swedish | glasövergångstemperatur |
| Finnish | lasisiirtymälämpötila |
| Ukrainian | температура склування |
Frequently asked questions
What does Glass Transition Temperature mean in engineering?
The glass transition temperature (Tg) is the temperature at which an amorphous polymer transitions from a hard, glassy state to a softer, rubbery state. It is a critical thermal property that affects mechanical behavior and processing conditions. In Manufacturing Engineering, the term carries a usage-frequency rating of 10/10 in the Engineering English library.
How do you pronounce Glass Transition Temperature?
Glass Transition Temperature is pronounced /ɡlæs trænˈzɪʃən ˈtɛmpərətʃər/ (IPA). The Engineering English app plays audio for the term and checks your pronunciation with speech recognition.
How is Glass Transition Temperature used in a sentence?
Example from an engineering context: “The glass transition temperature of the epoxy matrix was measured at 120°C, ensuring the composite maintains stiffness below that limit.”
This entry is one of 7,806 terms in the Engineering English iOS app — with quizzes, spaced repetition and pronunciation checking.
Get the app on the App Store