The document discusses the physical properties of polymers related to high elasticity. It explains that high elasticity is caused by the uncoiling of polymer chains over time when stretched. It describes the creep function, which quantifies the development of creep as chains uncoil towards equilibrium. It also discusses how orientation time, the time to reach equilibrium, is affected by temperature and frequency of stress application.

1. Physical Properties of Polymers Muhammad Zafar Iqbal Date: 24-04-2008

10. For a polymer: E = 60 Kcal T m = 100 Sec t = 100 Sec Temperature = 27 0 C = 300 K It means the transformation from rubbery to brittle behavior is very sharp if the polymer has high E-value.i.e. below this temperature, the material will break sharply under applied stress and its extensions at rupture is very little. Above this brittle point, the polymer stretches lazily and shows larger deformation. A brittle point is the temperature at which the material has a definite but unknown T value and most of times this is called Iso-elastic temperature.