Below solidifying or glass transition temperature (also referred to as “glass temperature”), the polymers not organised in the crystal lattice and polymer segments of a semi-crystalline plastic lose their ability to move. As a result, the properties of the plastic significantly change when the glass exceeds its transition temperature or falls below it.
Below the glass transition temperature, the hardness increases significantly
Below glass transition temperature, plastics loose their elastomer properties and become hard and brittle
- Surface energy:
And thus also the contact angle. The glass transition temperature of thermoplastics can be very easily determined by measuring the contact angle as a function of temperature.
The "solidifying" temperature has nothing to do with the melting temperature. The thermoplastic is solid below and above the solidifying temperature.