EXPERT WITHIN THERMOANALYSIS AND ANALYTICAL CHEMISTRY

Differential Scanning Calorimetry (DSC)

A polymer has a relatively broad melting range and this area often reflects the size of the crystalline parts that melt. The smallest parts melt first and the largest last. There are a variety of parameters that affect melting and it makes it important to investigate and control. With the help of DSC we investigate the melting process.

Glass transition

The glass transition temperature is when the material passes from its solid rigid structure to a more rubbery and soft or inverse. This temperature is usually termed Tg and is very important to be in control of because it often gives an indication of the temperature range within which the material can be used. The glass transition takes place in the amorphous part of the polymer. Tg can be altered by additives of, for example, plasticizers and it is also affected by other factors within the polymer. DSC is a good instrument for examining glass transitions.

Crystallinity

Crystallinity is an important parameter for the physical and mechanical properties of the material. The materials containing crystalline parts - so-called semi-crystalline - have a molecular structure that allows the chains to settle. Some types of material have no chance of settling because of steric barriers in the structure or many cross-links and these are called amorphous. We determine the crystallinity using DSC.

Thermal history

Through thermoanalytical measurements you can examine the thermal history of the material. How a detail has been manufactured and under what conditions can be revealed as well as possible impact of aging. Thermal history is investigated with DSC.

Differences between and within material batches

With the help of our thermoanalytical equipment, we can study both raw materials and processed details with respect to differences. General and modified methods with DSC are used for these types of tests.

Quality of raw materials

If you want to produce high quality products, it is important to have precise control over the incoming raw materials. Small differences can lead to major problems and these can easily be avoided through continuous controls. Methods can be customized with DSC to suit both the material you are investigating and the specific parameters that are considered sensitive to the process.

Study of the polymer structure

The polymer structure affects the results of DSC measurements and can thus be well investigated using this technique. Here you also have the opportunity to develop detailed and specific methods where you can receive exactly the information you are looking for.

Affect of processing conditions and parameters on materials

When manufacturing a detail, the process settings will have a major impact on the material and thus also the function and characteristics of the finished detail. Therefore, it is important that the settings are correct both with respect to the material, but also to make the process as efficient as possible. Testing with DSC can be an invaluable help in process optimization.

Effect of recycled material on material properties

Recycling materials reduces environmental impact and saves fossil fuels. This is good in many ways, but it is also necessary to take into account how the product manufactured manages the recycled material and whether the function is sufficient. Upon recycling, the material is affected by a process that changes its properties. DSC measurements make it possible to detect material changes and to clarify whether the intended material is capable of being manufactured from recycled material.

Polymer blends

Something that is quite common is to mix different polymers to achieve desired properties. Many times, the mixing ratio is critical for the function of the item being manufactured. DSC is a good instrument for studying polymer mixtures and the properties they have. The technique is also good at an early stage to investigate different mixtures to get the most optimal one.

Plasticizers effect on material properties

Plasticizers are added to some materials in order to achieve properties with respect to flexibility and softness in the structure. Some of the plasticizers have also been widely discussed in the media because of their suspected negative environmental impact and toxicity. Therefore, there is a constant search for new substitutes for the potentially dangerous ones and if you change, the materials often get altered properties that you may not think of or take into account. The effect of plasticizers can be studied with DSC but also other techniques.

Effect of molecular weight on material properties

Something that also affects the properties of polymers is the molecular weight. Polymeric materials with different molecular weights have different properties and altered physical parameters. Here the molecular weight distribution also plays an important role. This influence on different parameters of the materials can be studied with for example DSC.

Effect of other additives on material properties

Polymeric materials contain, in addition to the base polymer, various types of additives and fillers that are intended to provide for example altered properties or protect the polymer from degradation. Additives presence and absence largely affect the properties of the polymer material and how it can be used. Measurements can be made with, among other things, DSC to look closer and optimize additives.

Quality of injection molded items

An important part of the manufacturing of polymer materials is how the quality of the finished products is achieved. Is it ready for its intended use and how long can it last? If you study injection molded products using DSC, you will be able to answer many questions, and it is also important to monitor the quality on a regular basis with continuous tests.

Investigation of crosslinks

Crosslinks within the polymeric structure have a decisive influence on how the material will function in its intended use. Cross-linking can be studied to some extent using DSC and specific methods, but other types of instruments also provide good additional information.

Investigation of post-curing of materials

Certain types of polymeric materials require post-curing to ensure that the structure has its intended properties, while any residual products are vented. This process is important that it is carried out with the correct parameters so that the materials will not have altered properties or contain hazardous residues. With DSC, one can easily determine if the process has not been sufficient and optimize these parameters.

Investigation of adhesives and joints

Adhesives and joints are also important for their proper properties. This requires the correct procedure and complete cure for optimal function. DSC is used to study these conditions. You can also look at the kinetics and by optimizing receive the highest efficiency. Here it is also important to look at whether glue and polymer fit together and do not adversely affect each other by degradation.

Control of purity or contaminations

Purity and contamination are other parts that affect the materials. For example, if the process equipment is not sufficiently clean, it may induce smaller parts of polymers in others resulting in altered physical and chemical properties of which can lead to incorrect and failed products. Contamination from process equipment can also lead to future problems. With DSC you can get an idea of the purity and if there is some contamination, but this could also be investigated with other instrumentation.