POLYMERS

Quality Control of Polymers by means of DSC - Thermal Behavior of Thermoplastic Polyurethane

This plot shows a measurement on TPU. During the 1st heating, the EndothermicA sample transition or a reaction is endothermic if heat is needed for the conversion.endothermic step at -42°C (mid-point) reflects the Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.glass transition of the soft segments of the sample.

Additionally, the curve exhibits an EndothermicA sample transition or a reaction is endothermic if heat is needed for the conversion.endothermic double peak between 100°C and 210°C. The reversible part of it, which can be detected again in the 2nd heating (7.40 J/g), is caused by the melting of the hard (thermoplastic) segments. The irreversible part is probably due to evaporation of volatiles or distribution of additives in the polymer matrix. This process explains the fact that the Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.glass transition was detected at a higher temperature (mid-point at -28°C) in the 2nd heating.

Thermal properties of the soft and hard segments in a thermoplastic polyurethane (TPU). Sample mass: 10.47 mg; heating from -100°C to 250°C at 10 K/min, twice; dynamic N2 atmosphere.