EPOXY RESIN - A word with several meanings

Whether raw material component, finished formulation or cured product - even if they are different states of a product, they all have the same name - epoxy resin.
Take a little journey into the world of epoxy resin chemistry.

FRAGEN & ANTWORTEN

How are new products created?

In most cases, the basic raw material is bisphenol A diglycidyl ether. With this as the basis, an almost infinite variation of formulations is possible depending on the addition of other raw materials. This results in products that are, for example, accelerated, rheologically adapted, viscoplasticized, thermally conductive or electrically conductive. We develop epoxy resin formulations adapted to the respective requirements, from which optimum products are created after curing.

What are epoxy resins able to do?

Epoxy resins are thermosetting plastics which, in contrast to thermoplastics, are irreversibly cross-linked after curing, i.e. they do not become liquid again at higher temperatures. The typical properties of epoxy resins are:

  • Good chemical resistance
  • Hard (or flexible in our case)
  • Good mechanical properties
  • Good temperature resistance
  • Good adhesion
  • Good moisture resistance
  • Good electrical insulation properties

Epoxy resins - as flexible as silicone. Is that possible?

EPOXONIC - specialist for flexible resin systems.
Moulding materials made of epoxy resin are normally known to be particularly hard compared to other plastics. However, we also develop flexible epoxy resins. Flexible here means that we can produce molded materials with Shore hardness < A50 and a glass transition temperature well below ‑20°C. The well-known advantages of epoxy resins, is that they are particularly resistant to chemicals and/or temperature. The curing mechanism here requires hot curing, which is initiated either catalytically or by anhydrides. An example of a flexible, catalytic system is EPOXONIC 376

How are epoxy resins actually cured?

There are several methods to cure epoxies. The method depends on the type of epoxy resin, the application and the desired properties of the end product.

Amine curing

One way of curing epoxy resins is to react with amines.

Skizze

There is a wide range of amines that can be used for curing. Whether aliphatic, cycloaliphatic, aromatic, long-chain or short-chain, each of these amines can be reacted with epoxy resin. Depending on the application and hardener used, various properties are possible: room temperature curing or hot curing, glass transition temperature in the range of 50 - 150°C, 2-component systems (or 1-component systems).
A good example of this is our EPOXONIC 382.

Anhydride curing

One way of curing epoxy resins is to react with anhydrides.

Skizze

In anhydride curing, the anhydride is opened in the first step and reacts with the diglycidyl ether in the second step. Curing temperatures above 100°C are required for this step-by-step reaction. In return, this system allows a processing time of up to several weeks. Further advantages of this system are low reaction shrinkage, the possibility of casting large volumes without loss of reaction control and good processability. This hardener system allows one- or two-component formulations.

Catalytic curing

One way of curing epoxy resins is polymerization using catalysts

Skizze

Like anhydride curing, catalytic curing takes place at temperatures above 100°C. Here, hydroxyl groups present in the diglycidyl ether can react with the epoxy ring of another molecule. Tertiary amines or imidazoles, for example, can be used as catalysts. These systems are characterized by a long use duration and very high glass transition temperatures of up to 180°C can be achieved. These formulations are possible in both one- and two-component formulations.
A good example of this is our EPOXONIC 361

Profound research, development and testing -
an excerpt of our most important analysis devices

On the way to developing your individual product, we continuously check the specific material properties - directly, in-house, customer-oriented. Below you will find an extract of our various analysis options & devices.

DSC

We use Differential Scanning Calorimetry (DSC) with efficient devices both for outgoing goods testing and for the development of new resin systems. This allows us to determine properties such as the reactivity of the mixture or the glass transition temperature, an important parameter in polymer technology.

DSC is one of the most important analytical material tests at EPOXONIC due to the uncomplicated and fast sample preparation and measurement as well as the small amount of sample material.

Our DSC devices are ultra-modern and suitable for carrying out low-temperature measurements from -80°C even with flexible resins - our specialty.

TMA

The Coefficient of Thermal Expansion (CTE) is crucial for potting or bonding parts and components with different thermal expansion behavior. Thermomechanical analysis (TMA) is used to determine the CTE.

Our TMA device is ultra-modern and suitable for carrying out low-temperature measurements from -80°C even with flexible resins - our specialty.

Material testing machine

We use our material testing machine to precisely perform various mechanical tests on hardened test specimens. This device is able to determine important mechanical properties of materials and thus evaluate their quality and performance.

Applications include tensile, bending and compression tests in particular:

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  • We use the Tensile Test to determine the strength and ductility of a material. The sample is subjected to a tensile force until it tears. During the test, various parameters such as tensile strength, elongation and modulus of elasticity (E-modulus) are measured.
  • The Bending Test is used to determine the flexural strength and stiffness of a material. The specimen is loaded centrally to generate a deflection. The flexural modulus, strength and stress are determined.
  • The compressibility of a material is determined in the Compression Test. Parameters such as compressive strength, compressive stress and compressive modulus are measured by applying a uniaxial compressive load.

Pendulum impact mechanism

The pendulum impact tester is a testing machine for determining the Impact Strength of standardized test rods. It is used to characterize the robustness of a material under impact load by measuring the energy that a material can absorb. Knowledge of the energy absorption properties of a material is crucial for predicting what plastic or permanent deformation the material can withstand before it fails.

In practice, this material behavior is crucial when components are subjected to intensive and impact-like stress. It is therefore an important basis for decision-making in research and development.

Rheometer

Our state-of-the-art air-bearing rheometer enables a wide range of rheological tests. These provide highly accurate information about the viscoelastic properties of our products. Measurements can be carried out both in rotation and in oscillation, depending on the experiment and requirements.

The determination of viscosity, which is a very important product property, is a standard outgoing goods test.

However, the rheometer also plays an important role in the development process of new products. The yield point or thixotropy can be used to determine properties such as the stability and flow behavior of the product. Furthermore, we are also able to determine the sedimentation behavior of the fillers in the formulation with this measuring device.

Further analysis options

  • Heat conductivity
  • IR
  • Shore hardness
  • Shear strength
  • Density determination
  • Filler content
  • Wet chemical analysis

Deepen your knowledge, expand your expertise - relevant specialist articles and insights

Would you like to know more about us?
Here you will find a selection of in-depth information for experts and interested parties.

Flexible epoxy resin casting compound without acid anhydride

EPOXONIC offers flexible or viscoplastic sealing compounds free of SVHC ingredients.

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KA-TE PMO AG and EPOXONIC – a successful team

KA-TE PMO AG received an ICT Seal with a grade of 1.6 for sewage repairs using epoxy resins.

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Economical and precise dosing of thixotropic 1K adhesives

EPOXONIC 292, a thixotropic, high-strength 1K adhesive for increased temperature requirements, can be used with jet dispensing valves from Liquidyn for large production runs,
see film.

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Partnership & Collaborations

  1. Fluvius GmbH (Vertriebspartner)
  2. Mitglied Fördergemeinschaft SKZ
  3. Mitglied im Industrieverband Klebstoffe e.V.
  4. Materiales - Beratung & Compliance
  5. Künzel, Drews & Partner Managementberatung
  6. Scheugenpflug AG (Anlagen für die professionelle Gießharzverarbeitung)

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