Definition(s)
Glass Transition Temperature
Temperature at which the amorphous portion of the polymer undergoes a marked change in properties on passing from the rubbery to glassy state.
- Note: 1 to entry: This observed change in properties is associated with the virtual cessation of local molecular motion in the polymer. Below their glass-transition temperature, amorphous polymers have many of the properties associated with ordinary inorganic glasses, while above this temperature the polymers possess rubbery characteristics.
Source: ISO 14692-1:2017, Petroleum and natural gas industries — Glass-reinforced plastics (GRP) piping — Part 1: Vocabulary, symbols, applications and materials, Second Edition, August 2017. Global Standards
Glass Transition Temperature
The temperature below which elastomers exhibit brittle, glass-like behavior.
Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global Standards