TGA (Thermogravimetric Analysis)
We are equipped with two TGA analysers. Both systems are Perkin Elmer Pyris 1 TGAs and are capable of thermogravimetric analysis of materials with a typical precision of ±0.001mg over a temperature range of room temperature to 800°C and heating rates of up to 80 °C/min. One of the systems, recently purchased, is coupled to a 500 amu Hiden mass spectrometer to allow analysis of the volatiles generated by the thermal degradation of materials. We are able to study the degradation of materials under a variety of atmospheres including air, nitrogen, argon and others. The TGA is most frequently used to assess the thermal stability of materials prior to DSC experiments. However, the instrument is a powerful research tool in its own right. We can use TGA to detect and quantify the presence in samples of volatile materials such as moisture, solvents and plasticisers, and by analysing the residue left after heating to much higher temperatures we can measure the amount of inorganic materials such as glass fibres which might be present in composite materials. Finally, use of the instrument can be extended to include the determination of Curie temperature of magnetic materials.
DSC (Differential Scanning Calorimetry)
We have two DSC instruments. The first is a Perkin Elmer Pyris 1 DSC which is cooled with liquid nitrogen, enabling thermal characterisation from approximately -180 to 250°C, the instrument is equipped to examine solid or liquid samples. We are able to quantify the magnitude of thermal transitions such as melting points, glass transitions and crystallisation processes and the temperature at which they occur. A wide range of heating and cooling rates is available, which enables one to optimise the sensitivity in terms of enthalpy or temperature as required. Computer control enables complex measurement programs to be set up and multiple runs at variable heating rates can be carried out routinely. The Pyris 1 also has the capability of Hyper DSC, which allows heating rates of up to 200oC a minute. This can be useful in maximising the detection of thermal transitions such as glass transitions which are often small in magnitude. The recently acquired Q1000 DSC from TA instruments comes with autosampler, cooling capablities to -90oC and Advanced Tzero™ technology. This technology offers excellent baseline stability, sensitivity and resolution offering an alternative approach to analysing small transitions such as Glass transitions. It also includes Modulated DSC™ which allows the separation and analysis of simultaneously occurring reversible (eg melting point, Tg) and non-reversible (eg solvent loss, curing) processes.