vitreous state

…use include noncrystalline solid and vitreous solid. Amorphous solid and noncrystalline solid are more general terms, while glass and vitreous solid have historically been reserved for an amorphous solid prepared by rapid cooling (quenching) of a melt—as in scenario 2 of Figure 3.

…solid condition known as the glassy state. In the volume-temperature diagram shown in Figure 2, this state is represented by the points e (for amorphous polymers) and a (for semicrystalline polymers). As the polymer is heated, however, the molecules vibrate more energetically, until a transition occurs from the glassy state…

…what is known as the glassy state; there is little or no movement of molecules past one another, and the material is stiff and even brittle. Above T_g the amorphous parts of the polymer enter the rubbery state, in which the molecules display increased mobility and the material becomes plastic…