6.1 Polymer melts and glasses The transition from melt to glass is called glass transition(玻璃化转变) The transition from melt to solid(crystal) is called solidification(crystallization) Temperature Viscoelastic liquid Glass () Crystallization Transition (glasses) Melting fast cooled slowly cooled I quI slow T i IT. fast Semi-crystalline Solid Glassy Solid >Tg: glass transition temperature(玻璃化转变温度) Tm: Melting point AT=T-T: undercooling T<T: crystallization temperature6.1 Polymer Melts and Glasses (liquid) liquid glasses (glasses) slowly cooled fast cooled Tg slow Tg fast G T ¾ The transition from melt to glass is called glass transition (⧫⪳ॆ䖜ਈ) ¾ Tg : glass transition temperature (⧫⪳ॆ䖜ਈ⑙ᓖ) 2 Tm: Melting point Tc <Tm: crystallization temperature ¾ The transition from melt to solid(crystal) is called solidification(crystallization) 'T=Tm-Tc : undercooling