Thermal Analysis of Polymers

Interview conducted by G.P. ThomasNov 27 2013

AZoM talks to Juergen Blumm, Managing Director of Sales, Service and Marketing at NETZSCH, about the need for Differential Scanning Calorimetry (DSC) in the thermal analysis of polymers.

Could you provide a brief overview of the main groups of polymers that NETZSCH instruments can help to analyze?  

With NETZSCH instruments, all kinds of polymers can be characterized and analyzed. This includes a wide range of thermoplastic polymers and thermoplastic elastomers as well as elastomers and thermosets. Of course, the strength of thermo-analytical methods is in the characterization of compounds and composites.

A wide range of polymers is available commercially, including thermoplastic polymers and thermoplastic elastomers as well as elastomers and thermosets. Image Credit: NETZSCH

Could you briefly describe how DSC is used in the analysis of polymers?

Differential Scanning Calorimetry (DSC) is commonly used for polymer characterization with a focus on three typical applications. First, it’s a tool to get information on the thermal characteristics of a polymer compound or recipe, like glass transition, heat capacity, melting and crystallization behavior or curing reactivity.

Second, DSCs are used for quality assurance applications, where the method provides a fast and easy-to-use tool for quality inspections on incoming polymers, to avoid problems during processing or on the produced parts.

Of course, the third application field is failure analysis. Here, it is possible to determine if the performance of a part in terms of geometry, mechanics or thermal properties is caused by deviations in the polymer composition, the degree of crystallinity or the degree of curing.

How has the use of DSC increased over the last 20 years and what technical improvements have there been?

In fact, the DSC method has been more or less unchanged for decades. The main improvements have been increased sensitivity of the instruments and enhanced usability of the software.

The latest developments, however, make the entire system much more user-friendly and allow for very short testing times, due to higher heating and cooling rates. With a state-of-the-art DSC from NETZSCH, you don’t need to be an expert in polymer characterization to establish reliable quality assurance in your factory based on this method.

Why is it important to measure the thermal properties of polymers at injection molding and extrusion plants?

The thermal profile of a polymer is like its fingerprint. Within minutes you can know whether a new batch of raw material contains the correct ingredients and will allow for the manufacturing of reliable products.

With DSC, you may identify a material which is not suitable for production before the material enters the production machine. However, during the injection molding and extrusion processes, the polymer undergoes strong shear flow followed by rapid cooling in the mold cavity or extrusion die.

These processing conditions affect the solidification of the macromolecules and have an effect on internal tension and suppressed formation of crystallites. DSC enables a view into the polymer’s thermal history and gives information on how to optimize processing conditions.

Employing a DSC in your quality control lab results in continuous production of reliable products.

What other industries primarily benefit from the thermal analysis of polymers?

Wherever polymers are used for the manufacturing of complex parts, thermal analysis methods are employed.

The packaging industry, electronics manufacturers and the automotive industry are only some of the industries using polymers in their products. They employ thermal analysis in different stages of production as well.

The new DSC 214 Polyma from NETZSCH is dedicated to the characterization of polymers – could you explain a little about this new model and how the concept was developed?

The DSC 214 Polyma is the first DSC in the world developed to specifically fulfill the needs of the polymer field. After 2 years of development, NETZSCH has created a system which applies a comprehensive 360° view to DSC technology. Solutions for all tasks within the analysis chain have been developed, including sample preparation, measurement setup and analysis of the results.

The outcome is the fastest heat flux DSC in the world, with unique features such as fully automatic evaluation of the test results and a unique tool to directly identify the polymer under examination.

A work-station showing the new DSC 214 Polyma, SampleCutter and 3in1Box. Image Credit: NETZSCH  

How has sample preparation for this model been improved?

We have produced a sample preparation kit and cutting tools which allow for a proper sample derived from a granulate or a molded part to be cut within seconds.

The tools focus on creating a plane bottom surface to assure reliable thermal contact between the polymer sample and the pan. This ensures a certain level of consistency irrespective of the operator as well as optimum geometry for testing with a DSC.

How are the new software developments unique in the field of DSC analysis?

There are several new software features integrated with the DSC 214 Polyma. The first of these is SmartMode, a new graphic user interface allowing for the easy creation of a so-called measurement method. Predefined methods are included for a wide range of different polymers.

Such measurement methods make starting a measurement as easy as pressing a single button on a touch-panel. The software then automatically selects the correct temperature program, heating rate and gas condition. The circle is closed by two unique analysis tools, AutoEvaluation and Identify, which make measurement analysis and interpretation easier than ever before.

In summary, the software allows you to perform high-quality DSC measurements and data interpretation even if you are not an expert in thermal analysis.

The DSC 214 Polyma SmartMode Software. Image Credit: NETZSCH  

How is the novel Corona sensor integrated into the system?

The new Concavus pan has been designed to interact perfectly with the Corona sensor and the Arena furnace. The combination creates a thermal system characterized by maximum reproducibility, optimum sensitivity and high test speeds.

Our engineers carefully tailored the individual components to realize the best possible performance package for DSC analysis.

Diagram showing how the Arena furnace, Corona sensor and Concavus pan interact with each other. Image Credit: NETZSCH  

Could you tell us about the new ‘Thermal Properties of Polymers’ app from NETZSCH and who would benefit from this?

The “Thermal Properties of Polymers” app was developed in parallel with our poster series. The app and poster are standard tools for both newcomers and experts in getting an easy-to-use overview of the key properties of polymers.

All of this information on the thermal properties of standard polymers was gathered by our application experts. We are proud to say that thousands of tablets, cell phones and of course, lab walls are now equipped with this overview.

How do you feel DSC thermal analysis of polymers will change over the next few years and how will NETZSCH be a part of this?

The new DSC 214 Polyma will mark a new milestone in the thermal analysis of polymers. Thermal analysis experts will be impressed by its performance aspects.

People new to the field will see how beneficial thermal analysis can be in even their day-to-day research, development and production issues – and will find that they can apply it without needing vast experience in analytical instrumentation.

As the most progressive and fastest-growing company in thermal analysis, we are convinced that instruments from NETZSCH will be the best solutions for any kind of polymer characterization task around the globe.

About Juergen Blumm

Dr. Juergen Blumm  is the Managing Director of Sales, Service and Marketing at NETZSCH-Geraetebau GmbH after previously being Head of the Applications Laboratory.

Dr. Blumm studied of physics at the University of Wuerzburg and earned his PhD from the University of Wuerzburg in 2003.

Dr. Blumm is a reviewer in several journals including the International Journal of Thermophysics, High Temperatures - High Pressures and Applied Physics Letters.

He is also a member of several associations: VDMA, SPECTARIS and certain advisory boards at the Munich Exhibition Center.