Glass Transition Temperature (Tg)
Definition
Temperature where adhesive transitions from hard/brittle to soft/rubbery state.
Historical Background
1950s: DSC made Tg measurement possible, becoming a key formulation indicator.
Example
Tape softens in summer, hardens in winter. Like a personality switch.
Formula
Operating Range approx Tg +/- 30C
Core Concepts
Root of temperature sensitivity, determining the operating range.
Extended Applications
Automotive: -30C; electronic: +80C; medical: +25C; outdoor: -10C; aerospace: -50C to +200C.