Polymer testing is an extremely important part of plastic product development. Additives, contaminants, and a wide range of environments can all drastically affect the performance of a polymer-based product. Understanding how and why your polymer product will be affected in as many conditions as possible is crucial to ensuring quality and suitability for the product’s intended application.
A polymer testing lab uses a wide variety of techniques, each essential for quality assurance. Here’s what you should know about each polymer testing technique, and when you would need to use each one:
Fourier Transform Infrared Spectroscopy, or FTIR, is a versatile quality control materials analysis technique used to identify organic and some inorganic contaminants, in order to determine how they are affecting a product.
FTIR works by using a device called a spectrometer to direct a beam of infrared radiation (IR) at different wavelengths over a sample of the material being tested. Different molecules within the substance absorb these wavelengths of infrared radiation at different rates, producing a spectrum of IR frequencies which can be checked against a reference library to determine molecular composition.
FTIR is used to identify polymers, assess the quality of polymers used in plastic products, and analyze details about a polymer’s molecular structure. It’s particularly useful for comprehensively determining the composition of a plastic product, including the polymers present and the additives used. FTIR is commonly used in polymer testing because it’s fast, reliable, and doesn’t require the sample to be altered.
Differential Scanning Calorimetry (DSC) is a thermal quality testing and research technique that is used to measure changes in heat flow as a sample transforms from one state to another, or as it transitions into glass, crystallizes, or oxidizes.
In DSC, the sample being analyzed is placed inside an isolated chamber called a calorimeter, along with a surrounding control medium with known properties. Then, the chamber inside the calorimeter is subjected to different fixed and measured amounts of heat. The resulting difference in temperature between the sample and the control medium gives analysts information about the sample’s heat release.
Polymers are very susceptible to swings in temperature, which makes testing how they respond to heat transitions important for quality testing. DSC is used to measure the performance and degradation of polymers when exposed to a wide range of temperatures over a period of time. This technique can also be used to determine the melting point, enthalpy, heat capacity, and crystallinity point of polymers by increasing the temperature the polymer sample is subjected to at a measured, fixed rate and observing when these reactions occur.
Thermal Gravimetric Analysis, (TGA, sometimes called thermogravimetric analysis) is a technique that measures the weight changes of a sample material as it is heated or cooled in a controlled environment over time.
During TGA, the sample is placed inside a temperature-controlled environment that includes both an oven and a scale. The oven is used to apply a fixed, measured amount of heat to the sample, and then the sample’s mass is continuously monitored for changes over time. The changes in mass, such as gains or losses, are recorded and are indicative of the point at which the sample’s components oxidize, volatilize or decompose.
TGA is useful for testing the thermal stability of polymer-based products, especially those that need to withstand high or constant amounts of heat for long periods of time. It can also be used to determine the amount of inorganic filler which has been added to the polymer, and to observe how much weight the polymer product will lose when subjected to heated environments.
Electron Spectroscopy Chemical Analysis (ESCA), which is also known as X-ray Photoelectron Spectroscopy, is a surface analysis technique that determines the molecular and chemical composition of a material’s surface in order to derive information about the elemental and binding energy of its surfaces and interfaces.
ESCA passes an x-ray beam over the surface of a sample to “excite” the atoms on that surface. When these atoms are “excited” they absorb photon energy from the x-ray beam and eventually release core electrons, which emit onto the surface of the sample and can be detected by the testing equipment. Each element requires a different, specific amount of binding energy to emit their core electrons this way, which means by measuring how much energy each electron absorbed before emitting, ESCA can determine the elements present on a sample’s surface.
ESCA is used on polymers less frequently than other techniques on this list, because it requires a high level of expertise. It is, however, a highly-effective way to determine very specific information about the surface chemistry of a polymer product, including the presence and nature of any contaminants.
Innovatech’s experts regularly provide each of these polymer testing techniques to our clients, including ESCA. If you need to test your polymer product for any reason, Innovatech will determine the best testing technique for your needs and provide comprehensive analysis you can count on.