Glass transition temperature

The glass transition temperature is the temperature (range) at which glass solidifies i.e. becomes hard and brittle. As glass is a polymer, this term is used for plastics as well. These, too, become hard and brittle as glass when reaching or falling below the glass transition temperature with the risk of losing their properties as stability, impermeability, elasticity. Examples: materials (synthetic resin, PUR, bitumen, etc.), recipients/tubes (for fluids, gases, etc.), foils (tarpaulins, freezer bags, etc.), garden furniture.