Glass transition of a polymer

The answer to our question at the beginning of this summary therefore has to be as follows. When you want to locate the glass transition of a polymer melt, find the temperature at which a change in dynamics occurs. You will be able to observe a developing time-scale separation between short-time, vibrational dynamics and structural relaxation in the vicinity of this temperature. Below this crossover temperature, one will find that the temperature dependence of relaxation times assumes an Arrhenius law. Whether MCT is the final answer to describe this process in complex liquids like polymers may be a point of debate, but this crossover temperature is the temperature at which the glass transition occurs. 

The glass transition of a polymer is reduced by the presence of an additive, i.e.a solvent or nonsolvent. This glass transition depression can been described by various theories fiom which the one of KeUey-Bueche is widely used [28] (see chapter EL, eq. II - 6). A schematic phase diagram of the system PPO/trichloroethylene/methanol is shown in figure in - 34. Four regions can be observed ... 

The glass transition of a polymer in the vicinity of a composite interface depends on the extent of mixing see Chapter 12. If the polymer is attracted to or bonded to the filler interface, then such bonding may reduce the free... 

Tg oo glass transition of a polymer with infinite molecular weight [K]... 

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