Thermal analysis of materials

DSC can be used to determine transition temperatures and enthalpy changes in solids and liquids under controlled temperature change. Typical research subjects are characteristic temperatures of the material (e.g. melting, crystallization, glass transition temperatures) and their enthalpies, amorphous and crystalline behaviour of materials, curing behaviour and the degree of cure, specific heat, compatibility between material components, effects of different additives. Measurements of OIT (oxidation induction time) are possible. Temperature-modulated (TM-DSC) measurements allow separating some overlapping effects (reversing from non-reversing).

Technical details

• Liquid nitrogen cooling
• Automatic sample changer (ASC) for up to 18 samples
• Temperature range -170-600°C
• Heating rate: 0.001-100 K/min
• Cooling rate: 0.001-100 K/min
• OIT, TM-DSC
• Atmosphere: oxygen or nitrogen, other gas on request
• Reference material for Cp measurements: sapphire and Al2O3
• Sample size up to 2 g

DMA is used to determine the dynamic properties of materials, such as loss and storage moduli and loss factor. The viscoelastic properties of materials can be characterized as a function of time, temperature, frequency and strain. DMA/SDTA861 from Mettler Toledo is suitable for polymers and polymer blends, elastomers and composites with the wide range of stiffness. Time-temperature superposition analysis feature is available to create a mastercurve for a short- and long-term mechanical behaviour prediction.

Technical details

• Force range 5 mN to 40 N
• Temperature range -100 to 500°C
• Frequency range 0.001 to 1000 Hz
• Displacement range 5 nm to 1.6 mm

The tests can be run in three modes:

• Shear
• Tension
• Three-point bending (max 300 Hz)

DMA is used to determine the dynamic properties of materials, such as loss and storage moduli, loss factor and the stability of materials. The elastic, viscous and viscoelastic properties of materials can be characterized as a function of time, temperature, frequency and strain. PerkinElmer Pyris Diamond DMA is suitable for polymers and polymer blends, elastomers and composites.

Technical details

• Sample modulus: 103…1012 Pa
• Frequency: 0.01…100 Hz
• Temperature: -150…600°C
• Maximum load: static ± 10 N and dynamic ± 8 N

The tests can be run in four modes:

• Bending
• Tensile
• Shear
• Compression

In thermogravimetry (TG) weight changes are measured as function of temperature to perform compositional analysis and to determine kinetics of decomposition. Examples of TG applications: mass changes, decomposition temperatures, dehydroxilation, corrosion/oxidation, thermal stability, reduction studies, composition, filler content.

TGA can be connected to FTIR for simultaneous evolved gas analysis, which allows identifying gaseous products of reactions occurring during the TGA measurement

Technical details

• Temperature range RT to 1000°C
• Temperature resolustio 0.001 K
• Heating/cooling rate 0.001 – 100 K/min
• TG resolution 0,1 μg
• Atmosphere: N2, air, other gas on request

Technical details

• Simultaneous TG and DSC measurements
• Temperature range: -150 to 1600ºC
• Cp value measurements in DSC mode up to 1600 ºC
• Samples weighing up to 20 g

LFA is device which measures thermal diffusivity of sample using xenon flash as the heat source. If sample’s density and specific heat capacity is defined thermal conductivity of sample can be calculated.

Sample’s bottom surface is heated by short heat pulse. This pulse travels through samples thickness and is detected on top surface by IR-detector. Samples can be measured in one or multiple temperatures from -100°C-500°C range. LFA technique is best suitable for materials with ~0.1-2000 W/(m*K) thermal conductivity.

Technical details

Measuring ranges:

• Temperature: -100°C…500°C
• Thermal diffusivity: 0.01 mm2/s to 1000 mm2/s
• Thermal conductivity: < 0.1 W/(mK) to 2000 W/(mK)

Samples:

• up to 4 large or special samples (25.4mm square or Ø20mm round samples)
• up to 16 small samples (10 or 12.7 mm square or round samples)
• Special sample holders for fibers, powders, in-plane, and fluids

Dilatometry is used to study length changes in ceramics, glasses, metals, composites, and polymers to reveal information regarding their thermal behavior. The samples can be solid, powders or pastes.

Typically, the device is used to measure the coefficient of thermal expansion from sub-zero to high temperatures or to analyze volumetric phase changes or sintering in different atmospheres with temperature or force modulation. Other uses for the device are shrinkage steps, softening point, glass transition, density changes, decomposition temperatures, anisotrophic behavior, and thermal kinetics measurements.

Technical details

• Measuring range: 50 mm (± 25 000 µm)
• Δl Resolution (over entire measuring range): 0.1 nm
• Initial sample length: 0-52 mm (diameter 12 mm)                                                                               
• Temperature range : -180 °C to 1600 °C (accuracy 1 K, stability ±0,02 K)
• Heating rates : 0.001 to 100 °C/min
• Force range: 10 mN…3 N
• Gas Atmosphere: Inert, oxidizing, reducing or vacuum.

The cone calorimeter (manufacturer Fire Testing Technology) is used to determine the fire resistance of materials. The basic principle of the apparatus is based on the fact that the amount of heat released during the sample combustion is directly related to the amount of oxygen consumed. With cone calorimeter, the following parameters, for example, can be measured: time to ignition, mass loss rate, maximum amount of heat released during combustion and the time when it happens, total heat released as well as the amount of carbon dioxide and carbon monoxide released during the combustion. The equipment is suitable for a wide variety of materials such as coatings, textiles, insulators, construction materials, and other material combinations.

Technical details

• test area < 100 x 100 mm2
• thickness < 50 mm
• heat flux 0-110 kW/m2

HDT/Vicat Apparatus RAY-RAN/HDV2 to accurately determine the deflection and softening point characteristics of all thermoplastic test specimens.

Heat deflection / distortion test (HDT) is used to evaluate the maximum service temperatures of materials.  A standard sized test specimen is subjected to a bending stress, whilst the temperature is raised at a uniform rate. The temperature at which the specified deflection occurs is measured and recorded.

Vicat softening point test (VST) is used to determine the temperature at which the material starts to soften. A specified needle penetrates a specified distance into a sample with a specified load, whilst the temperature is raised at a uniform rate. The temperature at which the sample was penetrated is recorded.