Frequently Asked Questions

A phase change material absorbs and releases thermal energy at a specific, defined temperature, regulating the surrounding environment.

Ice is the simplest example of a phase change material. A frozen ice cube absorbs energy from its surroundings, causing a cooling effect, as it turns to liquid. On solidification to ice, heat is released to the surroundings.

Unfortunately, because water melts and freezes at 0°C, water can only provide temperature regulation around 0 °C, so Croda has developed an innovative range of materials that can be applied into a large range of applications that have different temperature requirements.

Latent heat is the amount of energy required to change the physical state of a material. e.g. from a solid to a liquid. The heat capacity of a PCM is mainly due to latent heat and this value is provided for all CrodaTherm products. 

To use ice as an example:

If a glass of ice cubes is placed in sunlight, the ice will also start to heat up but then they will start to melt. If you measure the temperature of the ice as it melts, you will find that until all the ice has melted, it will remain at 0ºC. This is because when ice changes phase, the temperature will remain constant until all the ice has melted. This is known as latent heat.

The latent heat of ice-water is 334 kJ/kg. This means that the thermal energy that is absorbed by 1 kg of ice for it to melt to 1 kg of water is 334 kJ assuming no change in temperature. This amount of heat is equivalent to heating up 1 kg of water to over 80°C. This is sensible heat, as you can feel the difference in temperature.

PCMs actually melt and freeze over a certain (usually narrow) temperature range, so the latent heat capacity is spread out over this range. We provide data on the heat capacity/temperature distribution in our technical data sheets.

CrodaTherm is a bio-based phase change material derived from plant-based feed stocks with very high latent heat capacities, making them ideal for use as a PCM.

Not all PCM materials are like CrodaTherm.

Salt hydrates are used as PCMs and cover a wide range of temperatures, but some are corrosive and toxic if ingested.

Paraffinic PCMs are also available, but most are flammable, hazardous to the environment and sometimes hazardous to health. Additionally, they are petrochemically derived, which can lead to volatile price increases in materials.

Crodatherm products are non-flammable, non-corrosive and are derived from renewable plant-based feedstocks making them the safer and more sustainable. Because of their good safety and environmental profile, CrodaTherm products mostly do not carry any hazard or warning labels.

By using renewable materials, non-renewable petroleum-based chemicals are displaced, helping reduce emissions of greenhouse gases.

As CrodaTherm will switch between the solid and liquid form in use, they need to be enclosed in a leak-resistant container suitable for the application they are to be used in. A wide range of containment methods are possible including, for example, rigid plastic bottles, flexible pouches, metal plates, tubes, mats and many more.

CrodaTherm has many applications where temperature regulation is needed. See our application pages on our website for more information.

Generally, CrodaTherm PCMs are biodegradable or readily biodegradable. This information is included in the safety data sheet for the CrodaTherm product of interest.

Developed with the 12 principles of green chemistry in mind, all our PCMs are bio-based and most are USDA certified biobased.

In most cases CrodaTherm products can be disposed of as non-hazardous industrial waste using an approved waste disposal provider. Refer to the safety data sheet for guidance.

CrodaTherm products are compatible with most metal and plastic materials used for handling and containment.

This means that contact of the PCM and the material does not lead to any unwanted effects such as weakening, migration etc.

Please note that certain plastics used for containers such as polyethylene may allow some migration of the PCM, which can usually be avoided by using a more resistant grade of plastic or film. Please contact us for guidance if this may apply to your project.

RAL PCM is the industry association for PCMs and they have set out guidelines on stability testing. 

CrodaTherm products have been tested according to RAL PCM methodology and found to meet the highest performance category ‘A’. To reach this, the material must be tested to 10,000 thermal cycles without degradation in properties or performance. This information is included in the CrodaTherm product technical data sheet.

Croda uses two methods to measure the thermal properties of our PCMs.

The first is differential scanning calorimetry (DSC).

DSC is an industry standard technique for determining heat capacity using a small sample (in the order of milligrams) of the PCM to be tested. DSC works by comparing the amount of heat that flows into the PCM against a blank control. The difference in heat flow between the sample and the blank control reflects the absorbed or released amount of heat of the sample. Based upon this, the latent heat during melting and crystallisation can be determined.

A second technique, called three-layer calorimetry (3LC), can be used to measure the heat stored by the PCM.

3LC is an industry standard technique for determining the heat capacity of a PCM that uses a much larger amount of sample (~100ml). With 3LC, the thermal properties are measured by cycling through melting and freezing temperatures of the PCM. The amount of energy stored and released through a phase change is measured.

Depending on the application, 3LC can give a much better representation of the “real world” behaviour of a PCM, because of the larger sample quantity, compared to DSC.

Note

You will find that the peak melting and crystallisation temperature is reported differently by the two methods. Croda reports the results from both DSC and 3LC methods so you can make an informed decision about the right phase change material for you. All results reported are typical, and we recommend completing your own testing to validate our products in your applications. Our technical experts can support you in the selection of the best CrodaTherm product for your application.

CrodaTherm materials are sold around the world into a diverse range of frozen, low, ambient and high temperature applications and we have 100 years of experience in developing innovative, plant-based chemistries.

As with any new ingredient, we advise our customers to test CrodaTherm to be sure performance is as expected. With a dedicated technical team and laboratories, we are always available to advise you on any specific issue you have.

Currently, CrodaTherm covers 12 temperatures from -22 to 60 °C. We are constantly developing new products within and outside our current temperature range. If you have a specific requirement, please contact us.

Croda manufactures all CrodaTherm waxes at our manufacturing site in Gouda in The Netherlands or at our site in Singapore. All products at these sites are manufactured to ISO 9001, ISO 14001 and ISO 18001 international standards meaning quality and consistency is assured.

Each CrodaTherm is designed with a specific discrete melting and freezing profile in mind. Please see our application pages for more information or contact us to discuss your requirements.

You can use our technical library to find technical data sheets. MSDS are available on request.

Most products are supplied in drums (net 170kg product) and Intermediate Bulk Containers (IBCs) (net 850kg product). For trial purposes we can supply product in small drums (net 16kg or 17kg product).

For ease of handling and optimum performance, CrodaTherm should be completely molten and homogenous before transferring from the container.

If stored at below the product’s freezing point for an extended period, the product may need heating before use.

Microcapsules are core-shell particles where the core material is usually enveloped inside a polymer shell.

Specifically, CrodaTherm patented microcapsules comprise a CrodaTherm core encapsulated in a durable acrylic polymer shell.

The individual capsules are smaller than the width of a single human hair and remain solid, even when the PCM inside the capsule changes phase.

Certain applications require the PCM to be available in the form of stable particles. This allows the PCM to be used as a technical “filler” that can be incorporated into liquid formulations, coatings, films, foams, fibres, construction materials etc. 

As the material can remain solid when CrodaTherm changes phase into a liquid, microencapsulation of CrodaTherm allows the material to be used when full containment of a liquid is not possible. This allows the beneficial thermal storage properties of CrodaTherm to be applied in new applications, where the wax is unsuitable.

Microencapsulated CrodaTherm can be used in textiles, construction and foam applications. For a full list, please see our application pages.

Croda manufactures CrodaTherm materials at our Gouda site in The Netherlands and in Singapore. We then microencapsulate the CrodaTherm wax at our site in Mevisa, Spain. Unlike other PCM suppliers, we are in total control of our supply chain, meaning the end product is the highest order of quality.

All sites are ISO 9001 and ISO 14001 certified.

Not all microencapsulated PCMs are like CrodaTherm.

Our patented core shell particles benefit from a high PCM content resulting in latent heat storage capacity that is similar and often superior to other microencapsulated PCM products in the market.

Moreover, some microencapsulated PCMs are manufactured using formaldehyde. All CrodaTherm products are 100% formaldehyde free.

CrodaTherm microcapsules are 100% formaldehyde free.

CrodaTherm microcapsules are durable and can tolerate high processing temperatures, demanding chemical environments and mechanical processing.

No, the microcapsules do not leak. CrodaTherm microcapsules have been put through rigorous testing and have been shown not to leak.

Thermal properties are measured using the same techniques as our CrodaTherm waxes. Please refer to the CrodaTherm waxes section for more information.

Our microencapsulated CrodaTherm materials have been rigorously tested internally to ensure maximum performance, durability and longevity in the end application.

As with any new ingredient, we advise our customers to test CrodaTherm to be sure performance is as expected. With a dedicated technical team and laboratories, we are always available to advise you on any specific issue you have.

Currently, only CrodaTherm 29 is available as a microencapsulated product. We are continuously developing new products that perform at different temperatures. Please enquire if you have a specific product in mind.

The CrodaTherm material is surrounded in an acrylic polymer shell, therefore the materials will have different latent heat and physical properties to the neat waxes. Please consult the technical data sheets for more information.

Our patented microencapsulated technology minimises the thickness of the acrylic shell, whilst maintaining shell strength. This means our microencapsulated product will be closer to the original neat wax latent heat capacity compared to competitor encapsulation technologies. 

Each CrodaTherm is designed with a specific discrete temperature profile in mind. Please see our application pages for more information or get in touch to discuss your requirements.

You can use our technical library to find technical data sheets. MSDS are available by request. 

The core wax material is manufactured at our PCM central hub in Gouda, The Netherlands. The wax is then microencapsulated at our specialist site in Mevisa, Spain. 

Microencapsulated CrodaTherm is available as a powder and an aqueous high solid content dispersion. The dispersion is supplied as a 50% solid dispersion in water by weight.

The powder product is available as 20 kg bags, 49 x 87 cm in size. 

The dispersion product is available in 900 kg IBCs, 190 kg drums and 25 kg pales.

Send your enquiry to CrodaTherm@Croda.com. A local sales person will be in contact to help.