We can offer a wide range of thermal analytical techniques and interpretation of the results. We never just give you the results and are always prepared to spend time helping you to understand the results and the implications for your business.
Thermal Analysis is a general name for a range of analytical techniques which includes Differential Scanning Calorimetry (DSC), Thermal Mechanical Analysis (TMA), Thermogravimetric Analysis (TGA) and Dynamic Thermal Mechanical Analysis (DTMA). Whilst they are similar in there operation each technique provides different information.
Differential Scanning Calorimetry (DSC) is just one of the thermal analysis techniques that we can use to study what happens to polymers when heated. We use it to study the thermal transitions of a polymer such as Tg (glass transition temperature), melting point, degree of crystallinity and degradation temperatures.
The DSC technique allows you to measure very small heat flow changes in a sample when compared to a blank reference. In simplistic terms you specify the heating rate of your sample and a computer measures the heat flow required to keep both the sample and the reference material at the same temperature. The result of the test is a curve of heat flow versus temperature for your sample or a thermogram. The figure below schematically demonstrates the principle of the apparatus.
Schematic of DSC operation
The beauty of this technique is that you can utilise very small samples, typically 10mg (approx. a 5mm cube) and hence analyse different parts of your product to build up a picture of the material and its processing.
The DSC also allows you to conduct both isothermal tests (constant temperature) and dynamic temperature scans at selectable rates. By linking together various scans you can conduct complex annealing cycles and studies of materials. A typical thermogram is demonstrated below for a two part epoxy system. The test has used a triple scan technique to determine the shift in cure of the epoxy and hence measure the overall degree of cure.
Thermal Mechanical analysis (TMA) is another thermal analysis technique and this works on the same principle but a small quartz probe is placed on the surface of the sample. The computer monitors change in dimensions of the sample versus temperature. The load on the sample can be varied as can the temperature scan rates. Hence, like DSC complex programs can be linked together to study the behaviour of the material. TMA is a very accurate method for measuring the thermal coefficient of expansion of a material and softening behaviour. The resulting thermogram is expressed as a % change in thickness versus temperature.
ThermoGravimetric Analysis (TGA) this technique monitors changes in the sample weight versus a temperature scan or fixed temperature. The balance is a highly accurate micro balance that can detect very small changes due to decomposition, drying or chemical reactions. The resulting thermogram of weight loss versus temperature can be used to determine compositional data about the material and quantify the level of fillers and additives.
Dynamic Thermal Mechanical Analysis (DTMA) utilises a dynamic loading condition. It typically applies a sinusoidally oscillating load to the sample and measures the sample response. This technique if very useful for measuring loss properties such as tan delta or transitions that are hard to detect by other means.
We can offer the full range of techniques and can produce custom cycles to meet your needs. We are highly experienced in thermal analysis interpretation and our methods have been used by the nuclear industry as quality control methods for incoming materials.
Call us now to discuss your specific needs.