Purpose

This procedure measures the quantity of energy absorbed or released as the temperature of a plastic sample increases from 50°C to 300°C, is quench cooled and then reheated from 50°C to 300°C.

Description

10mg of a finely ground sample is weighed out into an aluminum DSC boat. This sample is then heated to 30° above the anticipated melting temperature. It then is quickly quenched in liquid nitrogen to retain the properties of the material. At this point it then is reheated. During both of these heating periods, the caloric values of the energy required to make the temperature change are recorded. A graph is then produced and analyzed. From this analysis, glass transition temperature (Tg), crystallinity temperature (Tc) and melting temperature (Tm) are determined.