Contact person
Anna Bondeson
Forsknings- och utvecklingsingenjör
Contact Anna
Differential Scanning Calorimetry (DSC)
DSC is mainly used for analysing plastics, polymer fibers and coatings. Determination of melt temperature (Tm), glass transition temperature (Tg), Oxidation Induction Temperature- or Time (OIT) are very common. OIT is an indirect measure of the ability of a material to resist degradation by oxidation in air. Also curing reaction may be analysed.
Purpose
Most polymers have specific melt temperatures, or glass transition temperatures. Therefore DSC is often used to identify plastics and plastic mixtures. For identification of un-known samples DSC-analysis is often combined with FTIR (Fourier Transform Infrared) Spectroscopy.
Degree of crystallinity, miscibility of different polymers, curing reactions as well as heat capacity may be analysed. A very common analysis is oxidation stability of polyethylene or polypropylene. A sample is heated in air/oxygen and the time to thermal oxidaton or degradation is measured.
Method
In DSC thermal properties in an material are measured as a function temperature. A small test sample, typically 5-10 mg is placed in sample holder and heated at a constant rate or is held at constant tempererature. An empty crucible is placed in the instrument oven together with the test sample. Sample and reference are exposed to the same temperature program and the difference in temperature at thermal transitionis is registered. Melting of the sample needs more energy compared to the reference and causes a temperature difference, which is recorded in a thermogram.
The instrument temperature measure samples from -95°C up to 1100 °C and the heating rate varies betwee 0,1 till 100°C per minute.
Contact
DSC instruments are found at several locations at RISE and we collaborate to give our clients the best service and delivery time. In Mölndal the core comtenece is recycling and material formulation and processing (contact Anna Jansson), in Borås our expertise is focused on polymer constructon materials and accelerated ageing (contact Anna Bondeson), in Göteborg plastic pipes are analysed (contact Anders Höije) and in Stockholm/Kista we have competence on polymers used in chemical process industry (contact Carmen Cobo Sanchez).
Deliveries
Test results are delivered in a technical report including thermogram, where method used is described and results are explained.
