DSC ) is an essential thermal analysis method for evaluating a material's response to temperature changes. In an industrial context where materials science has become strategic, understanding their thermal behavior is crucial. Whether it's for quality control of a polymer, validating the stability of a protein, or optimizing the shaping of a composite material, engineers, formulators, and quality managers rely on advanced analytical tools. Discover the DSC analyses available in our catalog to better meet your needs.
This article guides you step by step through the principles, applications and challenges related to this reference technique.
Table of Contents
Introduction to DSC: why analyze the thermal behavior of materials?
Thermal control, a key challenge for industry
In all technical sectors – plastics, pharmaceuticals, cosmetics, food processing, and advanced materials – products undergo temperature variations during manufacturing, packaging, transport, and end use. These variations can lead to major physical or chemical transformations: melting , cross-linking, degradation, crystallization, or loss of stability . Without a thorough understanding of these behaviors, manufacturers risk non-compliance, reduced performance, and product defects.
Thermal analysis therefore makes it possible to anticipate these reactions and optimize formulations, processes, and conditions of use. In this field, DSC is indispensable.
A technique at the heart of quality control and R&D
Differential scanning calorimetry, better known by its acronym DSC, allows for the evaluation of how a material reacts to a controlled thermal program. It relies on the precise measurement of heat fluxes involved in phase transitions or chemical reactions within the analyzed material.
Thanks to this approach, DSC makes it possible to:
- determine the characteristic temperatures of a material (melting, crystallization, glass transition);
- measure the quantities of energy absorbed or released (enthalpy);
- evaluate the thermal stability of a product;
- verify the effectiveness of a heat treatment (crosslinking, hardening, baking);
- to characterize the nature and purity of a material.
It is therefore a valuable method for quality control departments, materials design offices, or R&D teams developing new products.
An accessible, fast, and versatile technology
DSC has many advantages that explain its popularity in the laboratory:
- It is applicable to a wide variety of materials: polymers, composites, metals, ceramics, pharmaceuticals, cosmetics, food, proteins…;
- it requires a small amount of sample (a few milligrams);
- It offers precise and reproducible results, even on weak or complex thermal transitions;
- It allows for rapid measurements, with typical cycles of a few tens of minutes.
Finally, modern equipment offers advanced options, such as temperature modulation control (MDSC), which allows for the separation of overlapping thermal events, or direct measurements of heat capacity.
A method supported by international standards
Like all laboratory analyses for industrial purposes, DSC is subject to strict regulatory frameworks. Laboratories performing DSC analyses must be accredited according to ISO 17025 to guarantee the reliability and validity of the results. In France, this accreditation is granted by COFRAC.
DSC analysis may also be required in certain specifications or regulatory frameworks, particularly in the food contact packaging or export polymer material
What is differential scanning calorimetry (DSC)?
Differential scanning calorimetry (DSC) is a thermal analysis technique that measures the heat exchange between a sample and an inert reference. When a material is subjected to a temperature change, it can absorb or release energy depending on the nature of the physical or chemical transformations it undergoes. DSC allows for the precise measurement of this difference in heat flow.
Scientific definition of DSC
DSC is an instrumental method used to measure the amount of energy (in joules) that a sample absorbs or releases as it is heated, cooled, or held at a constant temperature. It allows the detection of thermal events such as:
- physical phase transitions (melting, crystallization, glass transition);
- chemical reactions (crosslinking, polymerization, degradation, etc.);
- structural changes (relaxation, phase separation…).
The measurements are performed by comparing the thermal behavior of the sample to that of a thermally neutral reference placed in an identical crucible. The temperature is increased linearly (typically between 0.1 and 20 °C/min), and the difference in heat flux is recorded as a function of temperature or time.
Operating principle of the DSC
The fundamental principle of DSC is based on the fact that during a change of state, the sample exchanges energy with its environment to compensate for the thermal demands associated with the transition. This energy is reflected in a change in the heat flux measured by the instrument.
Two main types of transitions can be observed:
- endothermic processes , such as melting or glass transition, where the sample absorbs heat to maintain its constant temperature during the change of state;
- exothermic processes , such as crystallization or crosslinking, where the sample releases heat.
These phenomena are visible on the DSC thermogram as peaks (upward for exothermic events, downward for endothermic events in most systems). The peak is characterized by:
- its starting, peak and ending temperature;
- its surface, which corresponds to the enthalpy associated with the transition.
Measurement methods: heat flux and compensated power
There are two main types of DSC devices, which differ in their thermal detection method:
- Heat-flux DSC
is the most common method. The sample and the reference are placed in the same furnace, on a common support that ensures thermal conduction. The system measures the temperature difference between the two crucibles to deduce the heat flux. - Power-compensated DSC:
Here, the sample and the reference are housed in two separate but thermally coupled furnaces. Each furnace is heated independently, and the instrument continuously adjusts the power supplied to each crucible to maintain both at the same temperature. The difference in power applied is directly related to the heat flow from the sample.
Modern DSCs also allow modulated temperature modulation (MDSC) analysis, where sinusoidal temperature modulation is superimposed on the thermal program. This technique makes it possible to separate reversible (phase transitions) and irreversible (chemical reactions) phenomena, thus improving resolution in the case of overlapping thermal events.
Interpretation of a DSC thermogram
The thermogram is the central graph of the DSC analysis. It represents the difference in heat flux (in mW or mW/mg) as a function of temperature or time.
Here are some key elements to identify on a thermogram:
- Broad and progressive endothermic peak : glass transition (Tg), without significant change in enthalpy.
- Clear and symmetrical endothermic peak : melting (Tm), associated with significant heat absorption.
- Exothermic peak : crystallization, polymerization, or oxidation.
Analyzing the peak surface allows us to calculate the transition enthalpy (ΔH) , expressed in J/g. This data is essential for evaluating:
- the degree of crystallinity (in a semi-crystalline polymer);
- the degree of cross-linking (in a thermosetting material);
- or the purity of a compound, particularly in the pharmaceutical field.
The ability to detect weak thermal transitions, such as phase separation in a copolymer or partial denaturation of a protein, also makes DSC a very fine diagnostic tool.
Calibration and experimental conditions
To ensure reliable and reproducible results, DSC requires regular calibration, particularly on:
- temperature , with well-known reference materials such as indium (Tf = 156.6 °C, ΔH = 28.45 J/g) or zinc ;
- the heat flow , using certified standards.
Analyses must be performed under an inert gas (argon or nitrogen) to prevent oxidation or undesirable reactions, and with carefully prepared samples (mass, shape, absence of moisture). The choice of crucible (aluminum, airtight, open) depends on the nature of the material being studied and the type of analysis required.
In the following sections, we will explore the parameters measured by DSC as well as its many industrial applications.
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What parameters can be measured with a DSC analysis?
Dynamic scanning calorimetry (DSC) analysis provides a wealth of thermodynamic and structural information about a material. This data is invaluable for understanding its behavior during transformation, predicting its stability, and validating its functional properties. The results are based on direct measurements of heat exchange related to physical or chemical phenomena occurring at specific temperatures. The main parameters measured during a DSC analysis are listed below.
Glass transition temperature (Tg)
The glass transition (denoted Tg) is a fundamental characteristic of amorphous materials, particularly polymers, glasses, resins, and biopolymers. It corresponds to the transition from a rigid state to a more flexible or rubbery state without a change in physical state.
The glass transition temperature is measured as a plateau or inflection point on the thermogram , usually on a very broad peak. This transition is not accompanied by a massive heat exchange, but it is detectable by a change in heat capacity (Cp).
Measuring Tg allows us to:
- determine the conditions of use of a material (mechanical resistance at ambient or high temperature);
- to monitor the evolution of a product over time or after treatment;
- to control the stability of a polymer or composite after aging or sterilization.
Melting point (Tm) and crystallization point (Tc)
The melting temperature (Tm) corresponds to the transformation of a crystalline solid into a liquid. This transition is endothermic and is manifested on the thermogram by a sharp downward peak . The area of this peak allows the enthalpy of fusion (ΔHf) .
Conversely, the crystallization temperature (Tc) corresponds to the formation of an organized solid phase from a liquid or an amorphous material. This transition is exothermic , visible as an upward peak on the thermogram.
This data is essential for:
- optimize thermal transformation parameters (molding temperature, injection temperature, annealing temperature, etc.);
- quantify the degree of crystallinity (by comparing the measured enthalpy with that of a 100% crystalline material);
- analyze the cooling or annealing behavior of a polymer, metal or composite.
Reaction enthalpy and degree of crosslinking
Some materials, particularly thermosetting resins or organic matrix composites, undergo crosslinking (or hardening) when heated. This chemical reaction is often exothermic and generates a peak on the thermogram whose area corresponds to the enthalpy of reaction .
This measure allows us to:
- quantify the crosslinking rate of a resin (by comparing the energy released to the theoretical value);
- identify an incomplete cure or a cooking defect ;
- characterize the thermal cycle undergone by a composite part.
In formulation, the enthalpy of reaction is also useful for adjusting the proportions of hardeners, cooking times or processing temperatures.
Heat capacity (Cp)
Heat capacity, expressed in J/g·K, refers to the amount of heat required to raise the temperature of one gram of material by one degree. In some advanced DSC models, it can be measured directly from the absolute heat flux divided by the heating rate .
Monitoring Cp as a function of temperature allows for the observation of gradual changes in the structure or composition of the material. This is a particularly useful parameter for:
- detect gradual phase transitions ;
- observe phenomena of relaxation, aging or phase separation ;
- analyze the thermal behavior of proteins or complex substances.
Crystallinity level
The degree of crystallinity is an indicator of the structured order present in a semi-crystalline material. It is calculated by comparing the measured enthalpy of fusion (measured ΔHf) to the theoretical enthalpy of fusion of a 100% crystalline material (theoretical ΔHf), according to the formula:
Crystallinity percentage (%) = (measured ΔHf / theoretical ΔHf) × 100
For example, for high-density polyethylene (HDPE), the theoretical enthalpy of fusion is approximately 293 J/g.
Knowing this rate allows you to:
- adjust the structure and mechanical performance of a material;
- assess the quality of a heat treatment (annealing, quenching, cooling, etc.);
- detect partial degradation or crystallization .
Purity and homogeneity of a material
Finally, DSC is also used to estimate the purity of a compound (particularly in pharmaceuticals or fine chemicals), by analyzing the shape and position of the melting peak:
- a clear and unique peak corresponds to high purity;
- A broad or shifted peak may indicate the presence of impurities or polymorphs.
This analysis is valuable for:
- validate the quality of a pharmaceutical active ingredient (API);
- identify a contaminated or incorrectly formulated batch ;
- detect the presence of secondary phases or mixtures .
Industrial applications of DSC: a versatile tool
DSC is not just a laboratory tool reserved for research. It is an analytical technique widely used in industry for quality control, process optimization, and new product development. Its versatility makes it a strategic asset in many sectors. From engineering polymers to thermostable vaccines, every material can reveal its thermal and structural properties through a well-conducted DSC analysis.
Polymers and plastics sector
DSC is a reference method in the world of polymers. It allows for the precise characterization of thermal properties that determine their suitability for processing or use.
Industrial uses of DSC in this sector include:
- the determination of the glass transition temperature (Tg) to choose the temperatures for use or storage;
- the measurement of melting temperatures (Tm) to define the molding or extrusion parameters;
- the evaluation of the degree of crystallinity , which influences mechanical resistance, transparency or rigidity;
- the control of the crosslinking rate of thermosetting polymers used in adhesives, resins or composites.
Examples of applications:
- material validation for plastic injection (PP, PET, PA, POM…);
- batch tracking of HDPE for food packaging;
- Characterization of elastomers for the automotive industry.
Composite materials: thermosets and thermoplastics
In composite materials, particularly those with an organic matrix, DSC analysis plays a vital role at several stages of the product lifecycle.
The main applications include:
- the control of the crosslinking of thermosetting resins (epoxy, polyester, vinylester…) to validate the curing cycle or identify under-polymerization;
- the determination of the post-curing Tg , to ensure that the material will withstand the final mechanical and thermal stresses;
- the evaluation of the crystallinity of thermoplastic matrices (PEEK, PPS, PEI) used in aeronautics or medicine.
DSC is also valuable in failure analysis to detect a cooking error, a bad formulation or a deterioration of the material after aging.
Pharmaceutical and biomolecular industry
In the pharmaceutical field, DSC is used for active substances , finished formulations and therapeutic proteins .
Common uses include:
- characterization of the purity of the active ingredients (clear melting peak, absence of impurities);
- the measurement of the thermal stability of proteins (denaturation temperature, associated ΔH), essential for monoclonal antibodies, vaccines or enzymes;
- the study of ligand-protein interactions , to evaluate the efficacy or compatibility of an excipient;
- the verification of polymorphs or different crystalline states of the same compound, having an impact on solubility or bioavailability.
DSC is also useful in quality control of complex formulations such as suspensions, creams or combination devices.
Cosmetics and formulation
In cosmetics, the texture, stability, and performance of a product often depend on sensitive thermal balances. DSC allows for the objective assessment of the functional properties of formulations.
Among the main applications:
- study of thermal transitions in emulsions , to detect instabilities or risks of phase separation;
- analysis of the thermal stability of an active ingredient (vitamins, essential oils, fruit acids, etc.);
- characterization of anhydrous waxes, butters and bases , by their melting profiles;
- detection of the influence of an additive on the structure of a gel or serum.
DSC is also used to validate the effects of heat treatment (drying, sterilization) on the final formulation.
Agri-food products
The agri-food industry also uses DSC to characterize physical phenomena such as melting, crystallization or gelation.
Some typical applications:
- determination of the melting point of fats (butters, margarines, vegetable oils);
- analysis of the crystallization of sugars or starches , with influence on texture and preservation;
- study of vitreous transitions in powders (infant milks, flavourings, dry ingredients) to predict stability;
- evaluation of protein denaturation in processed or enriched products.
This data makes it possible to optimize processes (freeze-drying, extrusion, cooking), to control the quality of ingredients or to improve the shelf life of products.
Laboratory analyses by DSC: protocols, standards and quality of results
While DSC is a powerful and versatile method, its reliability depends primarily on strict adherence to analytical protocols, the selection of appropriate experimental parameters, and the application of quality standards. This section describes the key steps of DSC analysis in the laboratory, the regulatory requirements to be met, and best practices that ensure usable results, particularly in an industrial or regulatory context.
Sample preparation: a crucial step
A DSC analysis always begins with sample selection and preparation. These steps directly influence the quality of the thermal signal.
The main points to be aware of are:
- sample mass : generally between 2 and 20 mg, depending on the nature of the material and the desired resolution;
- physical state : the sample must be homogeneous, without residual moisture or impurities (especially for polymers and proteins);
- shape and thermal contact : the powder or fragment must be well distributed in the crucible for optimal heat transfer;
- Crucible type : aluminum for most analyses, airtight for volatile or oxidation-sensitive materials, gold or platinum for extreme cases.
Particular care must be taken with the initial weighing , carried out on a microbalance, because the calculations of enthalpy and heat capacity depend on the exact mass of the sample.
Experimental conditions: thermal programming and atmosphere
Once the sample is placed in the DSC, a temperature program is applied. This program is defined according to the properties of the material to be analyzed and the objective of the study.
The settings to configure are:
- temperature range : typically between -100 °C and +400 °C, up to +700 °C for high temperature DSCs;
- ramp speed : often between 2 and 20 °C/min; slower ramps are used for subtle transitions;
- isothermal segments : sometimes inserted before or after a transition plateau to observe thermal equilibria;
- Sweeping gas : usually nitrogen or argon (50 to 100 mL/min) to avoid oxidation or parasitic reactions.
Temperature modulated scanning calorimetry (MDSC) tests can also be conducted to distinguish overlapping transitions or to improve the resolution of glassy transitions.
Calibration and validation of the device
To ensure the accuracy of the results, the calorimeter must be calibrated regularly , both in temperature and enthalpy.
Calibration standards include:
- indium (Tf = 156.6 °C; ΔH = 28.45 J/g);
- zinc , tin or lead , to broaden the calibration range.
ISO 17025 accredited laboratories implement metrological verification , traceable to national standards. In addition, internal control materials (ICMs) may be used to validate each series of analyses.
Standards and compliance: ISO 17025 and regulated sectors
DSC analysis is governed by international standards that guarantee the competence of laboratories and the validity of results:
- ISO 11357 (parts 1 to 7): Reference standard for thermal analysis of polymers by DSC;
- ISO 17025 : a quality standard imposed on laboratories to guarantee the reliability, traceability, and impartiality of analyses.
In some sectors, DSC is also subject to specific standards:
- food packaging : compliance with EC regulation No. 1935/2004 on materials in contact with food;
- Cosmetics and nutraceuticals : safety and stability of formulations according to European guidelines.
Analysis reports must include all critical data: experimental conditions, thermograms, interpretation, uncertainties, signature of a responsible analyst, and mention of accreditation where applicable.
Interpretation and use of results
The final step in a DSC analysis is the interpretation of the thermogram. This phase requires expertise and perspective to:
- identify significant thermal events : phase transitions, chemical reactions, possible artifacts;
- quantify the thermodynamic parameters : temperatures, enthalpies, heat capacities;
- compare the profiles to those of standard materials or to previous data;
- to draw actionable conclusions : conformity, performance, alteration, aging…
A good laboratory does not simply provide a raw result. It must support the manufacturer in analyzing discrepancies , understanding root causes, and making decisions.
Why use YesWeLab for a DSC analysis?
Differential scanning calorimetry (DSC) is a high-precision thermal analysis technique essential for characterizing the thermal transitions of a material. To fully leverage the results and ensure data reliability, it is crucial to partner with a company that understands both the technical requirements and the industrial challenges. YesWeLab provides access to DSC analyses performed by specialized laboratories through a simple, fast, and centralized digital platform .
Advanced technical expertise for your complex materials
The results obtained by DSC are very informative, but require expert interpretation. YesWeLab laboratories offer:
- of experienced engineers in thermoanalysis, materials chemistry and formulation,
- with in-depth knowledge of numerous matrices: polymers, active ingredients, resins, cosmetics, proteins, fats, etc
- additional equipment to correlate thermal data with mechanical or chemical results (TGA, FTIR, HPLC, SEM…).
DSC analysis thus becomes a decision-making tool, allowing, for example, the identification of complex transitions, the comparison of thermal profiles, or the confirmation of conformity to a reference profile.
High-performance equipment accessible via a European network
Thanks to its network of over 200 partner laboratories in France and Europe, YesWeLab offers you:
- temperature-extended DSCs (up to 700 °C) with standard and modulated modes (MDSC),
- advanced cooling options, pressure controlled or technical coupling,
- customized protocols depending on the nature of the matrix and the objectives of the analysis.
Whatever your need — quality control, regulatory file, product development or applied research —, YesWeLab offers you the most suitable analytical solution via a single digital window.
Saving time, increasing reliability and compliance
Going through YesWeLab also ensures:
- with a quick turnaround , often within a few working days, even in emergencies,
- regulatory compliance : our partner laboratories are ISO 17025 accredited and their reports are accepted by the authorities (ANSM, EFSA, REACH, etc.),
- with complete traceability : protocols, results and interpretations are secured and audited,
- guaranteed confidentiality , with protection of your sensitive data.
This helps you avoid analytical errors, delays in your regulatory files, and non-conformities in production.
Personalized support from start to finish
YesWeLab doesn't just deliver results. Our approach is centered on customer support , with:
- assistance in defining analytical needs and choosing DSC parameters
- the validation of protocols adapted to your matrices,
- technical advice to optimize your formulations or processes,
- responsive monitoring at each stage of the project.
Thanks to our digital platform, you can easily manage your DSC analysis requests, from ordering to results processing.
Use case: when to use a DSC analysis?
Here are some concrete examples in which YesWeLab provides effective support:
- Quality control of a batch of polymer before processing,
- Thermal validation of a composite material for aeronautics,
- Optimizing the stability of a cosmetic or nutritional formulation,
- Analysis of a thermal deviation detected during accelerated aging.
