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Epoxy Reactive Diluents are low-viscosity reactive compounds used to improve the processability of high-viscosity epoxy resins, which not only physically dilute but also participate in the curing reaction. The most common types consist of aliphatic, aromatic, or special-function epoxy compounds bearing one or more glycidyl ether or epoxide groups.
Epoxy Reactive Diluents are different from conventional solvents. The reactive diluent can chemically bond to the epoxy mesh as the conventional solvent evaporates from the system during curing. Thus, high solids or completely solvent-free epoxy systems can be prepared while reducing viscosity.
The most basic task of Epoxy Reactive Diluents is to reduce resin viscosity. This effect provides significant advantages in high-fill floor systems, fiber-reinforced composites, adhesives, low-viscosity primers, casting and encapsulation systems, repair mortars, and different industrial coatings.
Epoxy Reactive Diluents cannot be identified by a single chemical substance or a single CAS number. Different molecules such as C12–C14 alkyl glycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, cyclohexane dimethanol diglycidyl ether, polypropylene glycol diglycidyl ether and trimethylolpropane triglycidyl ether can be included in this product group.
These products can be classified according to their functionality into single-function, two-function, and reactive diluents with three or more functions. Functionality affects not only viscosity-reducing capacity, but also the cross-link density of the cured epoxy mesh and the associated mechanical, thermal, and chemical properties.
Single-function epoxy reactive diluents carry one epoxide group per molecule. C12–C14 alkyl glycidyl ether and 2-ethylhexyl glycidyl ether are known examples of this group. These products usually have very low viscosity and can strongly lower the viscosity of the parent resin.
However, single-function reactive diluents can reduce the average cross-link density at high usage levels because they only join the epoxy network from a single point. This can increase flexibility and impact strength, but may have a negative impact on glass transition temperature, hardness, chemical resistance, or temperature strength.
Bifunctional epoxy reactive diluents carry two epoxide groups per molecule. 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether and cyclohexane dimethanol diglycidyl ether are examples of this class.
Bifunctional diluents can contribute more to the preservation of the cross-link structure compared to single-function products, as they can be connected to the epoxy network at two points while reducing viscosity. For this reason, it can be preferred in systems where it is desired to limit the loss of mechanical properties.
Trifunctional or higher-function reactive diluents carry three or more epoxide groups per molecule. Trimethylolpropane triglycidyl ether and certain propoxylated glycerin triglycidyl ether derivatives may be considered in this class.
In addition to reducing viscosity, these products can increase cross-link density or significantly change network structure. Therefore, it can be advantageous in systems that require high chemical resistance, temperature resistance, or mechanical performance; however, excessive use can increase brittleness.
Epoxy Reactive Diluents can also improve surface wetting. The low viscosity system can more easily penetrate concrete pores, pigment or filler surfaces, and between glass/carbon fiber bundles.
Therefore, the selection of reactive diluent should not be made solely on the question of "how many mPa·s viscosity does it provide?" Epoxy equivalent weight, functionality, volatility, odor, color, residual epichlorohydrin, hydrolyzable chlorine, amount of water, surface tension and performance of the cured material should be evaluated together.
WHAT ARE EPOXY REACTIVE DILUENTS?
Epoxy Reactive Diluents are epoxy formulation ingredients with low viscosity and containing epoxide or other reactive functions. The main purpose is to make the high viscosity resin system easier to process. This dilution is not only physical.
The reactive diluent participates in the reaction during curing. It is chemically bonded to the epoxy network. Therefore, it behaves differently from the standard volatile solvent.
When added to the solvent epoxy system, it lowers the viscosity.
However, it moves away from the system during curing or drying.
Evaporation:
Volatile organic compound emission
Volume loss
Film shrinkage
Pore formation
Smell
It can contribute to problems such as fire risk.
Reactive diluents, on the other hand, can become part of the cured network by participating in the reaction.
Therefore, it is important in the preparation of solvent-free or high-solids epoxy systems.
A significant proportion of reactive diluents are based on glycidyl ether chemistry.
Glycidyl ether has an epoxide ring in its structure.
This epoxy ring can react with amine or other suitable epoxy hardeners.
It has a similar reaction mechanism to the epoxy groups in the main DGEBA epoxy resin.
Because the reactive diluent is low molecular weight, its viscosity is much lower than that of the parent Bisphenol A epoxy resin.
For example, the viscosity of standard liquid Bisphenol A epoxy resin can be about 10,000 mPa·s or higher at 25 °C.
A single-function reactive diluent of the C12–C14 alkyl glycidyl ether type can be at about 5–15 mPa·s at 25 °C.
A bifunctional reactive diluent of the type 1,4-Butanediol Diglycidyl Ether can be at about 15–25 mPa·s.
This large viscosity difference significantly changes the flow behavior of the mixture.
When the reactive diluent is mixed with the mother resin, the average viscosity can drop rapidly.
This decline is often non-linear.
Even low proportions of reactive diluent can achieve significant viscosity reduction.
Actual viscosity:
Main type of resin
Type of reactive diluent
Amount of diluent
Temperature
Fill level
Pigment
Other contributions
determined by.
The choice of reactive diluent also changes the epoxy equivalent weight.
Because the reactive diluent has its own epoxy equivalent weight.
When mixed with the main epoxy resin, the total epoxy equivalent weight of the mixture must be recalculated.
Therefore, it is not always correct to add reactive diluent to the main resin and use it without changing the amount of old hardener.
In particular, two- and three-function epoxy diluents can form an important additional epoxide group in the system.
The amount of hardener should be recalculated based on the total epoxy equivalent.
Single-function diluents should also be included in the stoichiometric calculation as they carry an epoxide group.
Here are the key technical effects of Epoxy Reactive Diluents:
Reducing viscosity
Improving fluidity
Increasing filler acceptance
Enhancing pigment wetting
Increasing concrete penetration
Improving fiber wetting
Facilitating the release of air bubbles
Assisting in high-solids formulation preparation
Reducing the need for solvents
Adjusting mechanical properties
Changing flexibility
Changing the impact resistance
Changing cruciate ligament density
To be able to influence the curing speed
Be able to change the working time
COMMON PRODUCT AND CHEMICAL NAMES
Epoxy Reactive Diluents
Epoxy Reactive Thinners
Reactive Epoxy Diluents
Epoxy Diluents
Glycidyl Ether Diluents
Alkyl Glycidyl Ether
C12–C14 Alkyl Glycidyl Ether
C8–C10 Alkyl Glycidyl Ether
2-Ethylhexyl Glycidyl Ether
Syl Glycidyl Ether
p-tert-Butylphenyl Glycidyl Ether
1,4-Butanediol Diglycidyl Ether
1,6-Hexanediol Diglycidyl Ether
Neopentyl Glycol Diglycidyl Ether
Cyclohexane Dimethanol Diglycidyl Ether
Polypropylene Glycol Diglycidyl Ether
Polybutylene Glycol Diglycidyl Ether
Trimethylolpropane Triglycidyl Ether
Glycerin Triglycidyl Ether
Propoxylated Glycerin Triglycidyl Ether
Single Function Epoxy Diluent
Two-Function Epoxy Diluent
Three Function Epoxy Diluent
Not all of these names refer to the same chemical product.
"Epoxy Reactive Diluent" is a family of products.
C12–C14 alkyl glycidyl ether and 1,4-butanediol diglycidyl ether are not the same chemical.
Their functionality is different.
Epoxy equivalent weights are different.
Their viscosity is different.
Their effects on cured epoxy are different.
Therefore, product exchange should not be made only with the name of "reactive diluent".
CAS NO, EC / EINECS NO AND CHEMICAL IDENTIFICATION
Product Line: Epoxy Reactive Diluents
Chemical class: Low viscosity diluents with reactive epoxide function
Single CAS No: Not defined
Single molecular formula: Not defined
Single molecular weight: Not defined
Major chemical family: Glycidyl ethers
Major physical form: Low viscosity liquids
Role in the curing system: Viscosity reduction and participation in the epoxy reaction
Functionality: Usually 1, 2, 3, or more
Epoxy equivalent weight: Varies by chemical type
Water solubility: Varies with chemical structure
Volatility: Varies with chemical structure
Color: Mostly colorless or light-colored liquid; Grade dependent
Odor: Depends on chemical type and purity
C12–C14 Alkyl Glycidyl Ether:
CAS No: 68609-97-2
EC No: 271-846-8
Functionality: Approx. 1
Chemical structure: C12–C14 fatty alcohol monoglycidyl ether mixture
Typical epoxy equivalent weight: Approx. 275–315 g/eq, based on grade
25 °C viscosity: Approx. 4–15 mPa·s, according to grade
1,4-Butanediol Diglycidyl Ether:
CAS No: 2425-79-8
EC No: 219-371-7
Molecular formula: C₁₀H₁₈O₄
Functionality: Approx. 2
Typical epoxy equivalent weight: Approx. 108–125 g/eq, based on grade
25 °C viscosity: Approx. 15–25 mPa·s
Neopentyl Glycol Diglycidyl Ether:
CAS No: 17557-23-2
Molecular formula: C₁₁H₂₀O₄
Molecular weight: Approximately 216.28 g/mol
Functionality: Approx. 2
Typical epoxy equivalent weight: Approx. 125–145 g/eq, based on commercial grade
Trimethylolpropane Triglycidyl Ether:
CAS No: Different records can be seen according to the commercial chemical structure
Functionality: Approx. 3
Epoxy equivalent weight: Depends on grade
These values are given to show how the product family is diversified.
The TDS and COA information of the actual commercial reactive diluent purchased should be taken as basis.
CHEMICAL STRUCTURE AND MOLECULAR PROPERTIES OF EPOXY REACTIVE DILUENTS
A significant part of Epoxy Reactive Diluents have a glycidyl ether structure.
The glycidyl group contains an epoxide ring. This epoxide ring is a three-membered ring ether structure. The ring tension is high.
Therefore, it is open to reaction with amine hardeners. An epoxide group is present in the single-function reactive diluent.
A bifunctional reactive diluent has two epoxide groups. A trifunctional reactive diluent has three epoxide groups.
Functionality directly affects the network structure.
When a single-function diluent is connected to the end of an epoxy chain, it may not carry the second reactive point on itself that will continue the chain to another epoxy group. Therefore, it may have a terminating or flexible effect on network growth to a certain extent.
At a high level of use, the cross-link density may decrease. The bifunctional diluent has two different reaction points.
It can contribute to connecting two separate sections of the network. Therefore, it can further help maintain the cross-linked structure while maintaining low viscosity.
Since the trifunctional diluent carries three epoxide groups, it can create more binding points in the network. This can increase cross-link density.
However, not all trifunctional diluents necessarily increase hardness. The elasticity of the molecule's main chain is also important.
For example, a trifunctional reactive diluent with a long propoxylated chain can be both a trifunctional and flexibilizer.
Therefore, the mechanical result should not be estimated by looking only at the number of epoxide groups.
C12–C14 alkyl glycidyl ether is a single-function aliphatic reactive diluent. It has a long hydrocarbon chain.
This chain provides low polarity and certain flexibility.
Huntsman ARALDITE gives a viscosity of approximately 4–12 mPa·s and an epoxy equivalent weight of 278–317 g/eq for type C12–C14 alkyl glycidyl ether of type DY-E.
Aditya Birla EPOTEC RD 108 reports a viscosity of approximately 5–10 mPa·s and an epoxy equivalent weight of 275–300 g/eq for a similar C12–C14 fatty alcohol monoglycidyl ether structure.
This very low viscosity explains the strong dilution effect of the product.
1,4-Butanediol Diglycidyl Ether is a shorter-chain bifunctional aliphatic diluent.
Huntsman reports a viscosity of approximately 15–25 mPa·s and an epoxy equivalent weight of 117–125 g/eq for ARALDITE DY-D.
In another electronic grade, ARALDITE DY 026 grade, the viscosity is given below 15 mPa·s and the epoxy equivalent weight is given as approximately 108–118 g/eq.
The presence of two epoxide groups of these products can contribute to the preservation of the network structure.
Neopentyl Glycol Diglycidyl Ether has a branched aliphatic structure.
In EPA records, CAS No 17557-23-2 is identified by C₁₁H₂₀O₄ and a molecular weight of approximately 216.28 g/mol.
Huntsman reports a viscosity of approximately 10–18 mPa·s and an epoxy equivalent weight of 125–145 g/eq for the ARALDITE DY-N type commercial product.
Cyclohexane Dimethanol Diglycidyl Ether has a molecular skeleton with a more rigid ring.
For Huntsman ARALDITE DY-C, a viscosity of approximately 50–100 mPa·s and an epoxy equivalent weight of 153–167 g/eq are given.
The viscosity lowering effect of this product may be more limited than that of very low viscosity aliphatic single-function products.
In turn, better preservation of cured performance can be targeted.
Trimethylolpropane Triglycidyl Ether forms three-function epoxy structure.
High epoxy functionality can contribute to improving chemical and solvent resistance.
However, actual performance should be evaluated in conjunction with the hardener and formulation used.
The main properties of Epoxy Reactive Diluents at the molecular level are:
Low molecular weight
Low viscosity
Carrying Epoxide Group
Being able to react with amines
Ability to connect to the epoxy network
Reducing the viscosity of the main resin
Changing the equivalent weight of epoxy
Changing cruciate ligament density
Improving surface wetting
Changing the flexibility or hardness of the cured material
PHYSICAL AND CHEMICAL PROPERTIES OF EPOXY REACTIVE DILUENTS
Most of the Epoxy Reactive Diluents are colorless or light-colored low viscosity liquids at room temperature.
However, there is no single set of physical characteristics for the entire product family.
General technical specifications:
Physical form: Usually liquid
Color: Colorless to light yellow, depends on grade
Chemical class: Reactive diluent with glycidyl ether or other epoxide function
Functionality: 1, 2, 3 or more
Viscosity: From a few mPa·s to hundreds of mPa·s according to grade
Epoxy equivalent weight: Depends on grade
Density: Dependent on chemical structure
Epoxide value: Grade dependent
Hydrolyzable chlorine: Grade dependent
Total chlorine: Grade dependent
Amount of water: Depends on grade
Residual epichlorohydrine: Grade bound
Flash point: Dependent on chemical structure
Volatility: Depends on grade
Resin compatibility: Varies based on epoxy structure
Huntsman sample reactive diluent values:
C12–C14 alkyl glycidyl ether:
Viscosity: approx. 4–12 mPa·s
Epoxy equivalent weight: approx. 278–317 g/eq
1,4-Butanediol Diglycidyl Ether:
Viscosity: approx. 15–25 mPa·s
Epoxy equivalent weight: approx. 118–125 g/eq
Neopentyl Glycol Diglycidyl Ether:
Viscosity: approx. 10–18 mPa·s
Epoxy equivalent weight: approx. 125–145 g/eq
Cyclohexane Dimethanol Diglycidyl Ether:
Viscosity: approx. 50–100 mPa·s
Epoxy equivalent weight: approx. 154–167 g/eq
Polypropylene Glycol Diglycidyl Ether type:
Viscosity: approx. 42–90 mPa·s, according to chain structure
Epoxy equivalent weight: approx. 385–513 g/eq, based on grade
Trimethylolpropane-based trifunctional reactive diluents:
Viscosity: grade dependent
Epoxy equivalent weight: depends on grade
These examples are not the universal rule that proves that single-function products always have lower viscosity.
Molecular size and the structure of the main chain are also important.
Actual commercial TDS values should be used in the selection of reactive diluents.
HOW DO EPOXY REACTIVE DILUENTS WORK AT THE MOLECULAR LEVEL?
The first effect of Epoxy Reactive Diluents is physical viscosity reduction.
When low viscosity small molecules are added to high viscosity DGEBA resin, the average interaction between polymer chains decreases.
The mixture flows more easily.
A decrease in viscosity improves surface wetting.
Penetration into the micropores of concrete can increase.
The mineral filler surface can get wet more easily.
Pigment clusters can disperse more easily.
Resin can get between the glass or carbon fiber bundles faster.
The resin can flow more easily in the mold.
Air bubbles can rise more easily.
This physical advantage is particularly important in high-fill systems.
Calcium carbonate
Silica
Quartz
Alumina
Pigment
Glass fiber
The addition of solids such as increases the viscosity of the epoxy.
The reactive diluent can partially offset this viscosity increase.
But the process is not just physical dilution.
When curing begins, the epoxide ring present in the diluent reacts with the hardener.
The reactive diluent is included in the network structure.
Therefore, the sum of epoxy equivalents in the formulation varies.
An epoxy group is present in the single-function reactive diluent.
It participates in the reaction but creates fewer binding points in the network structure.
For this reason, a high level of single-function diluent:
May reduce cruciate ligament density
May improve flexibility
May increase elongation
May extend uptime
Glass can reduce the transition temperature
May reduce stiffness
May reduce chemical resistance
The degree of these effects depends on its dilutive and hardening nature.
Aditya Birla clearly states that as the level of use for C12–C14 monoglycidyl ether increases, the working time may be longer and the properties of the cured resin may change.
There are two epoxide groups in the bifunctional reactive diluent.
Therefore, it can connect the network structure at two points.
It may be easier to maintain the cross-link density than the single-function product.
Huntsman defines 1,4-Butanediol Diglycidyl Ether type DY-D as a product that provides good preservation of physical properties with a strong viscosity lowering effect.
Trifunctional reactive diluents carry three epoxide groups.
These products can increase cross-link density.
It can improve solvent and chemical resistance.
In turn, it can form a harder and more brittle network.
However, flexibilization may also be possible in three-function products containing propoxylated long chains.
For example, some products based on propoxylated glycerin triglycidyl ether can be used to increase elongation, impact resistance, thermal shock resistance and peel resistance.
Therefore, the "three-function = harder" approach alone is not enough.
The flexible chain length of the molecule must also be considered.
The main effects of Epoxy Reactive Diluents at the formulation level are:
Lowering viscosity
Improving the flow
Increasing surface penetration
Increasing filler acceptance
Enhancing pigment wetting
Improving fiber wetting
Facilitating air outflow
Changing the equivalent weight of epoxy
Changing curing behavior
Changing the working time
Changing cruciate ligament density
Changing the glass transition temperature
Changing the impact resistance
Changing flexibility
Changing chemical resistance
IN WHICH SECTORS ARE EPOXY REACTIVE DILUENTS USED?
Epoxy Reactive Diluents can be used in all sectors where the processability of high viscosity epoxy resin is important.
Main areas of use:
Epoxy floor coatings
Self-leveling floor systems
Concrete primers
Metal liners
Anti-corrosion coatings
High solids coatings
Solvent-free coatings
Structural adhesives
General purpose epoxy adhesives
Stone adhesives
Concrete repair systems
Epoxy mortars
Repair pastes
Joint systems
Crack injection resins
Electrical casting systems
Electronic encapsulation
Composite resins
Carbon fiber systems
Glass fiber systems
Resin infusion
Vacuum infusion
Filament winding
Mold resins
Casting systems
Marine applications
Automotive composites
Wind energy composites
Pigmented epoxy systems
High-filling epoxy compounds
Manufacturers like Huntsman and Cardolite position reactive diluents specifically in coatings, adhesives, flooring systems, concrete repair, and composite applications.
SOIL, COATING AND CONCRETE APPLICATIONS OF EPOXY REACTIVE DILUENTS
The primary reason for using reactive diluents in epoxy floor systems is to control viscosity.
Standard liquid epoxy resin alone can be highly viscous.
When pigment and filler are added, the system becomes even darker.
In self-leveling flooring, the formulation needs to be spread evenly over the surface.
Very high viscosity:
Weak spread
Trowel track
Air bubble
Poor surface smoothness
Insufficient concrete penetration
It can cause problems such as.
The reactive diluent can lower the viscosity, resulting in better surface spread.
Penetration is important in concrete primer.
Low-viscosity resin can penetrate concrete pores more easily.
This can promote mechanical locking and adhesion.
However, low viscosity alone is not a guarantee of high adhesion.
Concrete surface preparation
Humidity
Surface resistance
Powder
Oil
The type of hardener is also important.
In high-fill epoxy floor mortars, the reactive diluent can improve mineral filler acceptance.
Being able to use more quartz or other mineral fillers can contribute to formulation economics.
However, a high amount of reactive diluent can alter the cured properties.
For this reason, the ratio should not be increased only on viscosity and cost target.
Using a reactive diluent instead of a volatile solvent in coating systems can help reduce the total amount of volatile organic compounds.
This approach is important in high-solids or solvent-free epoxy coatings.
Single-function C12–C14 alkyl glycidyl ether type diluents can be widely used in floor and metal/concrete primers due to their high viscosity lowering power.
Bifunctional reactive diluents may be preferred in high-performance coatings where it is important to limit the loss of properties.
USE OF EPOXY REACTIVE DILUENTS IN ADHESIVE, COMPOSITE AND ELECTRONIC APPLICATIONS
In adhesive formulations, the reactive diluent can enhance surface wetting.
It can facilitate the penetration of the adhesive into micro-roughness on metal, concrete, wood, or composite surface.
It can also allow the use of mineral fillers and thixotropic additives at high levels.
However, excessive use of single-function diluent in adhesive:
Glass can reduce the transition temperature
May reduce shear strength
It can reduce the temperature resistance
It can reduce creep resistance
For this reason, bifunctional or performance-protective reactive diluents can be preferred in structural adhesives.
Manufacturers such as Cardolite position bifunctional reactive diluents to provide low viscosity and balanced mechanical properties.
Resin viscosity is very important in composite systems.
Thin gaps within the carbon or glass fiber bundles need to be completely filled with resin.
High viscosity epoxy can lead to insufficient fiber wetting.
This is:
Dry fiber zones
Spaces
Interlayer weakness
Low mechanical strength
can create.
The reactive diluent can lower the viscosity, increasing fiber wetting and infusion rate.
However, in composites, glass transition temperature and mechanical performance under temperature can be critical.
Therefore, the use of high amounts of single-function diluents may not be desirable.
In electrical and electronic encapsulation systems, low viscosity makes it easier to fill thin cavities.
However, ionic impurities and especially chlorine content are important in these applications.
Hydrolyzable chlorine
Total chlorine
Water
Residual epichlorohydrin
Values such as can be controlled more tightly.
Huntsman electronic grade 1,4-butanediol diglycidyl ether products are able to offer special purity for this type of application.
ARE EPOXY REACTIVE DILUENTS USED IN FOOD, COSMETICS AND PHARMACEUTICAL APPLICATIONS?
Epoxy Reactive Diluents are not food additives.
It is not used as a standard raw material in cosmetic formulations.
General purpose technical grades should not be used as pharmaceutical active or excipients.
Some epoxy systems can be used on food contact surfaces or potable water contact coatings.
However, this compliance should only be verified by regulatory documents for the fully cured final system and exact formulation.
Adding a reactive diluent to the epoxy formulation can alter the migration profile.
Uncured residual epoxides or low molecular weight compounds should be specially considered in food contact applications.
The presence of a CAS number or the REACH registration of a substance does not imply food contact approval.
For this reason, standard industrial grades of C12–C14 alkyl glycidyl ether or diglycidyl ether should not be automatically considered suitable for food contact.
Epoxy systems used in medical device or electronic medical equipment also require separate conformity assessment.
INDUSTRIAL APPLICATIONS OF EPOXY REACTIVE DILUENTS
Epoxy Reactive Diluents are used in industry as viscosity regulator and reactive component that joins the epoxy network.
Major industrial functions:
Lowering epoxy viscosity
Improving the machinability of filled systems
Increasing concrete penetration
Enhancing pigment wetting
Improving fiber wetting
Speeding up resin infusion
Prepare a high-solids coating
Reducing the need for solvents
Improving air output
Improving casting performance
Improve surface spread
Adjusting mechanical properties
Increasing or maintaining flexibility
Regulating cruciate ligament density
Changing chemical resistance
The following parameters should be evaluated in the formulation of Epoxy Reactive Diluent:
Chemical structure
Functionality
Epoxy equivalent weight
Viscosity
Density
Color
Amount of water
Hydrolyzable chlorine
Total chlorine
Residual epichlorohydrin
Volatility
Smell
Flash point
Compatibility with the main resin
Compatibility with hardener
Dilution yield
Effect on epoxy equivalent weight
Impact on uptime
Effect on gel duration
Effect on curing speed
Effect on glass transition temperature
Effect on hardness
Effect on impact resistance
Effect on elongation
Effect on chemical resistance
Impact on water resistance
Effect on adhesion
TDS
SDS
COA
As the amount of diluent increases, the epoxy equivalent weight of the system must be recalculated.
For example, if a certain amount of C12–C14 alkyl glycidyl ether is added to 100 units of DGEBA resin, the total epoxy equivalent of the mixture should not be calculated based on the EEW of the parent resin alone.
The epoxide equivalent of each component must be included in the account.
This calculation is critical for stiffening stoichiometry.
WHAT PROBLEMS CAN EPOXY REACTIVE DILUENTS HELP SOLVE?
Epoxy Reactive Diluents can help solve formulation problems, especially those caused by high viscosity and insufficient surface penetration.
Epoxy resin is very viscous
Low viscosity reactive diluent can improve the flowability of the formulation.
The floor covering does not spread properly
The reactive diluent can improve surface spread by reducing viscosity.
Concrete primer does not penetrate enough
The low-viscosity formulation can enter the concrete pores more easily.
When filler is added, the system becomes excessively dark
Reactive diluent can improve the workability of high filler load.
Composite resin does not wet the fiber enough
Viscosity reduction can facilitate resin entry between fiber bundles.
Air bubbles remain in the casting system
Lower viscosity can make it easier for bubbles to rise to the surface.
The adhesive does not wet the surface sufficiently
Low surface tension and low viscosity can increase the contact area.
It is necessary to reduce the amount of solvent
The reactive diluent can remain in the system instead of the solvent and participate in the reaction.
Epoxy is very brittle
Long flexible chain or suitable single-function reactive diluent can improve flexibility.
However, the mechanical and thermal properties should be checked separately.
Epoxy glass transition temperature too low
In this case, the use of too much single-function reactive diluent may be a problem.
Two or multi-function products can be preferred or the diluent level can be reduced.
Chemical resistance is declining
Cross-link density and reactive diluent functionality should be re-evaluated.
Operating time is very short
Some single-function aliphatic reactive diluents may prolong the working time.
However, the actual effect depends on the hardener system.
The system remains soft after curing
It should be checked whether the stoichiometry of the hardener has been recalculated relative to the epoxy equivalent of the reactive diluent.
Not every viscosity problem should be solved by simply adding more diluent.
Temperature
Main resin selection
Bisphenol F epoxy usage
Fill level
Hardener viscosity
Other parameters such as can also be evaluated.
THINGS TO CONSIDER WHEN USING EPOXY REACTIVE DILUENTS
In the use of Epoxy Reactive Diluents, functionality, epoxy equivalent weight and safety are the basic parameters.
The following issues should be considered during use:
The exact chemical species must be determined.
The CAS number must be verified.
Functionality should be known.
The epoxy equivalent weight should be checked.
Viscosity should be checked.
Compatibility with the resin must be verified.
The hardener ratio must be recalculated.
The ratio of single-function diluent should be checked.
The effect on glass transition temperature should be studied.
The hardness change should be followed.
Impact strength should be measured.
Chemical resistance should be tested.
Water resistance should be evaluated.
Working time should be measured.
The gel duration should be followed.
The curing speed should be evaluated.
Exotherm behavior should be controlled.
Hydrolyzable chlorine should be checked.
Residual epichlorohydrine should be checked if necessary.
The amount of water should be controlled.
TDS should be examined.
SDS should be examined.
The COA should be checked.
Many types of glycidyl ether reactive diluents can be skin sensitizers.
This is particularly important in the safety assessment of epoxy reactive diluents.
Skin irritation and allergic skin reaction classifications can be seen for common single-function diluents such as C12–C14 alkyl glycidyl ether.
1,4-Butanediol Diglycidyl Ether is also a separate epoxy chemical registered under REACH.
Therefore, the term "diluent" does not mean that the product is mild or harmless.
Skin contact with concentrated reactive diluent should be avoided.
Appropriate chemical gloves should be used.
Eye protection should be provided.
Ventilation and occupational hygiene conditions specified in the SDS should be applied.
INITIAL FORMULATION APPROACHES FOR EPOXY REACTIVE DILUENTS
The following examples are laboratory initial approaches prepared to show how epoxy reactive diluents can be evaluated in formulation development.
These are not verified commercial prescriptions.
Actual ratios should be determined based on epoxy equivalent calculation, mechanical performance and manufacturer TDS information.
EXAMPLE 1: SINGLE-FUNCTION EPOXY REACTIVE DILUENT VISCOSITY SCREENING
Purpose: To evaluate the effect of C12–C14 alkyl glycidyl ether level on the viscosity and cured properties of standard liquid DGEBA resin.
Starting components:
Control – diluent-free
Standard liquid DGEBA epoxy resin (EEW 190 g/eq): 79.17%
C12–C14 Alkyl Glycidyl Ether (EEW 295 g/eq): 0.00%
Amine hardener (AHEW 50 g/eq): 20.83%
Total: 100.00% (by weight)
Trial A – 5 phr single function diluent
Standard liquid DGEBA epoxy resin (EEW 190 g/eq): 75.67%
C12–C14 Alkyl Glycidyl Ether (EEW 295 g/eq): 3.78%
Amine hardener (AHEW 50 g/eq): 20.55%
Total: 100.00% (by weight)
Trial B – 10 phr single function diluent
Standard liquid DGEBA epoxy resin (EEW 190 g/eq): 72.45%
C12–C14 Alkyl Glycidyl Ether (EEW 295 g/eq): 7.25%
Amine hardener (AHEW 50 g/eq): 20.30%
Total: 100.00% (by weight)
Calculation assumption: DGEBA EEW = 190 g/eq, C12–C14 Alkyl Glycidyl Ether EEW = 295 g/eq and amine hardener AHEW = 50 g/eq. The requirement for hardener was determined using the total epoxy equivalent × AHEW. The percentages are the weight-by-weight ratios of the total mixture including the hardener. No filler was used. If the TDS values of the actual products are different, all percentages should be recalculated.
Application approach:
The epoxy equivalent weight of the parent resin is recorded.
The epoxy equivalent weight of the reactive diluent is recorded.
Resin mixtures of different diluent ratios are prepared.
Viscosity is measured at 25 °C.
The new epoxy equivalent weight of the mixture is calculated.
The amount of hardener is adjusted accordingly.
Operating time is recorded.
Standard plates are poured.
Full curing is applied.
Hardness is measured.
Tensile or bending performance is compared.
The glass transition temperature is measured if required.
Chemical resistance is checked.
The optimum level is determined between viscosity gain and property loss.
EXAMPLE 2: TWO-FUNCTION EPOXY REACTIVE DILUENT HIGH FILL SCREENING
Purpose: To evaluate the effect of 1,4-Butanediol Diglycidyl Ether or Neopentyl Glycol Diglycidyl Ether type diluent on a high-fill epoxy floor system.
Starting components:
Control – diluent-free, 80phr filling
Liquid DGEBA epoxy resin (EEW 190 g/eq): 47.94%
1,4-Butanediol Diglycidyl Ether (EEW 120 g/eq): 0.00%
Micronized calcium carbonate (dry mineral filler): 38.35%
Pigment (titanium dioxide): 0.96%
Deaeration additive: 0.14%
Amine hardener (AHEW 50 g/eq): 12.61%
Total: 100.00% (by weight)
Trial A – 8 phr diluent with diluent, 120 phr filler
Liquid DGEBA epoxy resin (EEW 190 g/eq): 38.46%
1,4-Butanediol Diglycidyl Ether (EEW 120 g/eq): 3.08%
Micronized calcium carbonate (dry mineral filler): 46.16%
Pigment (titanium dioxide): 0.77%
Deaeration additive: 0.12%
Amine hardener (AHEW 50 g/eq): 11.41%
Total: 100.00% (by weight)
Trial B – 12 phr diluent with disfunction, 160 phr filler
Liquid DGEBA epoxy resin (EEW 190 g/eq): 32.72%
1,4-Butanediol Diglycidyl Ether (EEW 120 g/eq): 3.93%
Micronized calcium carbonate (dry mineral filler): 52.35%
Pigment (titanium dioxide): 0.65%
Deaeration additive: 0.10%
Amine hardener (AHEW 50 g/eq): 10.25%
Total: 100.00% (by weight)
Calculation assumption: DGEBA EEW = 190 g/eq, 1,4-Butanediol Diglycidyl Ether EEW = 120 g/eq, and amine hardener AHEW = 50 g/eq were accepted. Filler, pigment, and deaeration were not included in the epoxy equivalent calculation. The compatibility of the pigment and deaerator with the resin and hardener should be verified. Since the filler increase and diluent increase change together, additional experimental design is recommended to interpret the effects separately.
Application approach:
The resin and reactive diluent are pre-homogenized.
Mixture viscosity is measured.
The filling is added gradually.
The mixer load is monitored.
The highest level of workable filler is determined.
The total epoxy equivalent weight is calculated.
Hardener is added accordingly.
Self-propagation behavior is tested.
Air outlet is observed.
Hardness is measured in cured samples.
Compressive and flexural strength are evaluated.
Chemical resistance is checked.
It is compared with the control formulation.
EXAMPLE 3: SINGLE AND DOUBLE FUNCTION DILUENT COMPARISON SCAN
Objective: To evaluate the difference between single-function and bi-functional reactive diluents that provide the same target viscosity over cured epoxy.
Starting components:
Control – diluent-free
Same DGEBA epoxy resin (EEW 190 g/eq): 79.17%
C12–C14 Alkyl Glycidyl Ether (EEW 295 g/eq): 0.00%
1,4-Butanediol Diglycidyl Ether (EEW 120 g/eq): 0.00%
Amine hardener (AHEW 50 g/eq): 20.83%
Total: 100.00% (by weight)
Trial A – single function, 8 phr
Same DGEBA epoxy resin (EEW 190 g/eq): 73.70%
C12–C14 Alkyl Glycidyl Ether (EEW 295 g/eq): 5.90%
1,4-Butanediol Diglycidyl Ether (EEW 120 g/eq): 0.00%
Amine hardener (AHEW 50 g/eq): 20.40%
Total: 100.00% (by weight)
Trial B – two-function, phr 8
Same DGEBA epoxy resin (EEW 190 g/eq): 72.65%
C12–C14 Alkyl Glycidyl Ether (EEW 295 g/eq): 0.00%
1,4-Butanediol Diglycidyl Ether (EEW 120 g/eq): 5.81%
Amine hardener (AHEW 50 g/eq): 21.54%
Total: 100.00% (by weight)
Calculation assumption: DGEBA EEW = 190 g/eq, single-function diluent EEW = 295 g/eq, two-function diluent EEW = 120 g/eq, and amine hardener AHEW = 50 g/eq are assumed. The comparison is made at the same 8 phr diluent loading in the first stage; there is no guarantee of the same viscosity. Separate concentration optimization and 25 °C viscosity measurements are required for co-viscosity comparison.
Application approach:
Both systems are set to the same targeted initial viscosity.
The required diluent percentages are recorded.
The equivalent weight of the new epoxy is calculated separately for each mixture.
The amounts of hardener are adjusted individually.
Working times are compared.
Gel times are measured.
Hardness is compared in cured samples.
Impact strength is measured.
Elongation is measured.
The glass transition temperature is compared.
Water and chemical resistance are evaluated.
The most suitable functionality is selected according to the application.
ALTERNATIVES AND COMPARISON OF EPOXY REACTIVE DILUENTS
When selecting an Epoxy Reactive Diluent alternative, only the initial viscosity should be considered.
Functionality, epoxy equivalent weight, volatility, and cured performance should be evaluated together.
SINGLE-FUNCTION AND TWO-FUNCTION EPOXY REACTIVE DILUENTS
Single-function products can usually achieve very strong viscosity reduction.
C12–C14 Alkyl Glycidyl Ether is typical of this class.
It provides low viscosity and good wetting.
In contrast, it can reduce cross-link density at a high level of use.
Bifunctional products carry two epoxy groups.
1,4-Butanediol Diglycidyl Ether and Neopentyl Glycol Diglycidyl Ether are in this class.
It can further contribute to maintaining the mesh structure while reducing viscosity.
For this reason, it can be preferred in systems that require high mechanical or thermal properties.
The two classes are not one-to-one alternatives to each other in terms of weight.
C12–C14 ALKYL GLYCIDYL ETHER AND 2-ETHYLHEXYL GLYCIDYL ETHER
Both products are in the class of unifunctional aliphatic glycidyl ether.
The C12–C14 product carries the longer alkyl chain.
2-Ethylhexyl Glycidyl Ether has a different branched hydrophobic structure.
Viscosity reduction, surface tension, and cured flexibility behaviors can be different.
Odor and volatility can also vary.
Exactly the same exchange should not be made.
1,4-BUTANDIOL DIGLYCYL ETHER AND NEOPENTYL GLYCOL DIGLYCYL ETHER
Both products are bifunctional aliphatic epoxy diluent.
1,4-Butanediol Diglycidyl Ether has a linear structure.
Neopentyl Glycol Diglycidyl Ether has branched center structure.
Both can provide very low viscosity.
Chemical resistance, hydrolytic behavior, and mechanical properties can be different.
The hardener calculation should be redone according to the epoxy equivalent weight.
TWO-FUNCTION AND THREE-FUNCTION EPOXY REACTIVE DILUENTS
Two-function products connect the network structure at two points.
Three-function products can provide higher port.
Three-function products can improve chemical or solvent resistance.
However, hardness and brittleness may increase.
For three-function products with long flexible chains, an increase in flexibility in the opposite direction may also be possible.
Therefore, the molecular backbone must be evaluated.
EPOXY REACTIVE DILUENTS AND VOLATILE SOLVENTS
Volatile solvents physically lower the viscosity of epoxy.
It does not participate in the cured network structure.
It is largely removed from the environment during drying.
The reactive diluent, on the other hand, remains in the system and participates in the reaction.
Therefore, the reactive diluent provides an advantage in high solids or solvent-free systems.
However, it should be noted that the reactive diluent alters the cured mechanical and thermal properties.
Therefore, a one-way evaluation should not be made as "it is always better because it is solvent-free".
EPOXY REACTIVE DILUENTS AND LOW VISCOSITY BISPHENOL F EPOXIES
Using reactive diluent is not the only method of reducing viscosity.
Some Bisphenol F-based epoxy resins may exhibit noticeably lower viscosity than standard Bisphenol A epoxy resin.
In the Huntsman portfolio, some Bisphenol F resins are found at approximately 1,200–3,000 mPa·s at 25 °C, while standard DGEBA systems may exhibit higher viscosity.
Therefore, it may be more appropriate to choose a low viscosity main epoxy resin instead of using excessive reactive diluent in the system where high glass transition temperature or high chemical resistance is targeted.
QUALITY CONTROL AND PURCHASING CRITERIA FOR EPOXY REACTIVE DILUENTS
When purchasing Epoxy Reactive Diluent, the exact chemical structure should be known.
The expression "Reactive Diluent" or "Epoxy Diluent" alone is not sufficient for the definition of purchase.
Recommended information to review before purchasing:
Full product name
Manufacturer
Chemical structure
CAS No
EC No
Functionality
Epoxy equivalent weight
Epoxy value
Viscosity
Viscosity measurement temperature
Density
Color
Outlook
Smell
Amount of water
Hydrolyzable chlorine
Total chlorine
Residual epichlorohydrin
Volatile matter
Flash point
Surface tension
Compatibility with major epoxy resins
Recommended use case
Effect on glass transition temperature
Effect on hardness
Impact on flexibility
Effect on impact resistance
Effect on chemical resistance
Impact on uptime
Effect on curing speed
Shelf life
Storage temperature
Packaging
Batch number
Origin
TDS
SDS
COA
REACH information
Epoxy equivalent weight is one of the most important technical criteria.
Because it helps to both verify product identity and calculate stiffener stoichiometry.
Viscosity, on the other hand, indicates the basic commercial function of the product.
However, it is not correct to choose only the lowest viscosity product.
The cured properties of a single-function very low viscosity product and a two-function slightly higher viscosity product can be very different.
Hydrolyzable chlorine and residual epichlorohydrin are especially important in electronics and high-purity applications.
For example, for Aditya Birla EPOTEC RD 108, a maximum of 0.1% hydrolyzable chlorine, a maximum of 0.1% water and a maximum of 10 ppm epichlorohydrin are reported.
These values belong to the specific grade.
It should not be generalized to all C12–C14 alkyl glycidyl ether products.
STORAGE AND HANDLING OF EPOXY REACTIVE DILUENTS
Storage: Reactive diluents should be stored in clean, dry, and tightly closed packaging.
Temperature: Exact should be based on the commercial product's TDS and SDS recommendations.
Heat: Unnecessarily high temperature may affect product color or quality stability.
Humidity: Water contamination should be avoided.
Water can adversely affect curing and surface quality in some epoxy systems.
Acids and bases: Uncontrolled contact with strong acids, bases or reactive amines should be avoided.
Amine: The reactive diluent should be kept separate during storage as it may react with the amine hardener.
Oxidizers: Must be stored separately from strong oxidizers.
Packaging: Drum, IBC or other compatible packaging recommended by the manufacturer should be used.
Contamination: Improper product mixing with other epoxy, hardener or solvents should be avoided.
FIFO: Batch and shelf-life management should be implemented.
Transportation: ADR, IMDG and IATA classification must be verified from the exact product SDS.
The transport class of different glycidyl ethers may not be the same.
For this reason, the transport class of a reactive diluent should not be generalized to the entire product family.
EPOXY REACTIVE DILUENTS SAFETY INFORMATION
Epoxy Reactive Diluents can spread easily on the skin due to their low viscosity.
While this feature provides an advantage in terms of use, it requires special attention in terms of exposure.
A significant proportion of glycidyl ether-type reactive diluents may have skin sensitization potential.
These substances can react with biological molecules because they carry an epoxide group.
Repeated skin contact can lead to allergic contact dermatitis.
Skin irritation and allergic skin reaction classifications are found in the safety sources for C12–C14 alkyl glycidyl ether CAS No 68609-97-2.
The current European regulatory status of this chemical should also be checked with the exact manufacturer's SDS.
Epoxy Europe states that C12–C14 alkyl glycidyl ether and some other epoxy building blocks are subject to additional toxicological evaluation and classification processes in Europe.
1,4-Butanediol Diglycidyl Ether is a separate substance registered under CAS No 2425-79-8 de REACH.
Therefore, when working with reactive diluents:
Suitable chemical resistant gloves
Protective eyewear
Protective workwear
Adequate ventilation should be implemented.
The product should not be allowed to get on the skin.
Contaminated gloves or clothing should not be used for long periods of time.
Exact personal protective equipment selection should be made through SDS.
The risk profile of cured epoxy material and uncured reactive diluent is not the same.
Uncured low molecular weight glycidyl ethers may be more critical to exposure.
WHAT SHOULD BE CONSIDERED WHEN BUYING EPOXY REACTIVE DILUENTS?
When purchasing an Epoxy Reactive Diluent, the target formulation should be determined first.
Is the goal only to reduce viscosity?
Increase flexibility?
High filler acceptance?
Composite infusion?
Chemical resistance?
Is electronic purity?
questions should be answered.
The following information should be clarified before purchasing:
Use sector
Floor covering
Metal plating
Adhesive
Composite
Electronics
Casting
Repair mortar
Concrete primer
Target initial viscosity
Main type of epoxy resin
Epoxy equivalent weight
Desired dilution strength
The need for a single-function product
The need for a two-function product
The need for three-function products
Glass transition temperature target
Flexibility
Impact resistance
Chemical Resistance
Water resistance
Operating time
Curing temperature
Stiffener used
Chlorine limit
Residual epichlorohydrin limit
Water limit
Color
Smell
Volatility
Manufacturer
Origin
Packaging
Estimated order quantity
TDS
SDS
COA
REACH documents
If the existing product is to be replaced, the TDS information of the existing diluent
The price of Epoxy Reactive Diluent should not be compared only per kilogram.
The more effective diluent can provide the same viscosity at a lower utilization rate.
Even if the two-function product is more expensive, it can provide higher cured performance.
The product with low chlorine and low residual epichlorohydrin can create higher value in electronic applications.
Therefore, the actual cost should be calculated based on the target formulation performance.
EPOXY REACTIVE DILUENT SUPPLY FROM ATAMAN KIMYA
Epoxy Reactive Diluents; epoxy floor coatings, high solids coatings, adhesives, composites, concrete repair systems, electronic casting and different industrial epoxy formulations are reactive epoxy compounds used to reduce viscosity and improve workability.
Companies that want to get information about the supply of Epoxy Reactive Diluents from Ataman Kimya can share their final applications and target technical specifications and request current supply conditions, packaging options and price quotes about the appropriate single-functional, two-function or multifunctional product.
The current stock status, manufacturer, origin, exact chemical structure, CAS number, epoxy equivalent weight, functionality, viscosity, packaging and other quality characteristics of the product should be confirmed from Ataman Kimya before ordering.
Sharing the following information in the request for quotation facilitates the evaluation of the appropriate Epoxy Reactive Diluent:
Use sector
Final Product
Main type of epoxy resin
Viscosity of the main resin
Target viscosity
Reactive diluent functionality
Epoxy equivalent weight requirement
Stiffener used
Uptime target
Glass transition temperature expectation
The need for flexibility
Chemical resistance target
Water resistance
Amount of filler
If there is a composite application, fiber type
Chlorine limit if there is an electronic application
Residual epichlorohydrin limit
Color requirement
Estimated order quantity
Requested packing
Requested technical documents
TDS or COA information of the current reactive diluent, if applicable
FREQUENTLY ASKED QUESTIONS ABOUT EPOXY REACTIVE DILUENTS
What is Epoxy Reactive Diluent?
It is a low-viscosity reactive component that lowers the viscosity of epoxy resin and reacts during curing and binds to the epoxy network.
Is Epoxy Reactive Diluent a solvent?
It is not a volatile solvent in the classical sense. It reduces viscosity but can remain in the system during curing and participate in the reaction.
Are Epoxy Reactive Diluents a single chemical?
Very different glycidyl ether and epoxide structures are included in this product group.
Do Epoxy Reactive Diluents have a single CAS number?
Nope.
What is the CAS number of C12–C14 Alkyl Glycidyl Ether?
CAS No is 68609-97-2.
What is the CAS number of 1,4-Butanediol Diglycidyl Ether?
CAS No is 2425-79-8.
What is the CAS number of Neopentyl Glycol Diglycidyl Ether?
The CAS No is 17557-23-2.
What do Epoxy Reactive Diluents do?
It lowers viscosity, improves flow and wetting, facilitates the use of high filler, and can alter the properties of cured epoxy.
What is a single-function reactive diluent?
It is the diluent that carries about one epoxide group per molecule.
What is a bi-function reactive diluent?
It is the reactive diluent that carries two epoxide groups per molecule.
What is a three-function reactive diluent?
It is the diluent that carries three epoxide groups per molecule.
Why is a single-function reactive diluent used?
It can achieve very strong viscosity drop and good surface wetting.
What happens if the single-function reactive diluent is used too much?
Cross-link density, glass transition temperature, hardness and chemical resistance may decrease.
What is the advantage of bi-function reactive diluent?
It can better maintain the cross-linked structure of the epoxy mesh than single-function products while reducing viscosity.
What does a three-function reactive diluent provide?
It can increase cross-link density and, in some systems, chemical/solvent resistance.
Is the lowest viscosity reagent diluent always the best?
The cured mechanical and thermal properties should also be considered.
Why is epoxy equivalent weight important?
It is necessary for the correct calculation of the amount of hardener.
Does the hardener ratio change when reactive diluent is added?
It is subject to change. Epoxy equivalents of the reactive diluent should be included in the total account.
What can happen if the hardener rate is not recalculated?
Insufficient or excess hardener may occur and cured properties may deteriorate.
What is the viscosity of C12–C14 Alkyl Glycidyl Ether?
Depending on the commercial grade, it can be at approximately 4–15 mPa·s.
What is the epoxy equivalent weight of C12–C14 Alkyl Glycidyl Ether?
Depending on the commercial grade, it can be at the level of approximately 275–315 g/eq.
What is the viscosity of 1,4-Butanediol Diglycidyl Ether?
It can be around 15–25 mPa·s according to commercial grade.
What is the epoxy equivalent weight of 1,4-Butanediol Diglycidyl Ether?
Commercial grades can be found at levels of approximately 108–125 g/eq.
Is reactive diluent used in floor epoxy?
It can improve self-leveling, filler acceptance, and concrete penetration.
Is reactive diluent used in glue?
It can be used to improve viscosity and surface wetting.
Is reactive diluent used in composite?
It can improve fiber wetting and infusion behavior.
Is reactive diluent used in electronic encapsulation?
However, chlorine and ionic impurity criteria may be particularly important.
Does the reactive diluent enable solvent-free formulation?
It can help reduce the need for solvents and develop completely solvent-free systems.
Is reactive diluent volatile?
It depends on the product. Some low molecular weight products may have higher volatility than others.
Can reactive diluent be odorous?
The smell depends on the chemical structure and purity.
Does reactive diluent affect run time?
Some products may extend the operating time or change the curing speed.
Does reactive diluent reduce glass transition temperature?
Especially single-function products can lower when used at a high level.
Do two-function products also affect Tg?
However, the effect depends on the molecular structure and the amount of use.
Does reactive diluent make epoxy flexible?
Some long-chain or single-function products can increase flexibility.
Can reactive diluent increase hardness?
Certain high-functioning products can increase the hardness by increasing the cross-link density.
Is Epoxy Reactive Diluent used in cosmetics?
It is not used as a general-purpose cosmetic raw material.
Can Epoxy Reactive Diluents be dangerous?
Many glycidyl ethers can be skin sensitizers and irritants.
EPOXY REACTIVE DILUENTS – TECHNICAL SUMMARY
Epoxy Reactive Diluents are low-viscosity reactive compounds that improve the flowability of high-viscosity epoxy resins and chemically incorporate into the epoxy network during curing.
Their main difference from conventional volatile solvents is that they can participate in the reaction rather than evaporating from the cured system.
This is why it is important in high-solids or solvent-free epoxy coatings, flooring systems, adhesives, and composites.
Epoxy Reactive Diluents are not the only product that belongs to a single chemical class.
There are unifunctional, bifunctional, and multifunctional glycidyl ethers.
C12–C14 Alkyl Glycidyl Ether is one of the common single-function reactive diluents identified by CAS No 68609-97-2.
A viscosity of about 5–15 mPa·s and an epoxy equivalent weight of about 275–315 g/eq can be seen in these types of products.
Huntsman ARALDITE DY-E and Aditya Birla EPOTEC RD 108 are commercial examples for this chemistry.
1,4-Butanediol Diglycidyl Ether is a bifunctional epoxy reactive diluent with the formula CAS No 2425-79-8, EC No 219-371-7 and C₁₀H₁₈O₄.
A viscosity of about 15–25 mPa·s and an epoxy equivalent weight of about 108–125 g/eq can be seen in commercial products.
Neopentyl Glycol Diglycidyl Ether CAS No 17557-23-2 is another bifunctional reactive diluent with C₁₁H₂₀O₄ and a molecular weight of approximately 216.28 g/mol.
Single-function products can provide very strong viscosity reduction but can reduce cross-link density and glass transition temperature at high usage levels.
Bifunctional products can make more contributions to maintaining the epoxy network structure while reducing viscosity.
Tri-function products can provide higher cross-link density, but the actual mechanical result also depends on the main chain structure of the product.
In addition to reducing viscosity, Epoxy Reactive Diluents can improve surface wetting, concrete penetration, pigment and filler dispersion, fiber wetting and the egress of air bubbles.
The addition of reactive diluent changes the total epoxy equivalent weight of the formulation.
Therefore, the amount of hardener must be recalculated based on the new total epoxy equivalent.
A high level of use should not be evaluated solely in terms of viscosity.
Glass transition temperature, hardness, impact resistance, elongation, chemical resistance and water resistance should be measured separately.
A significant proportion of glycidyl ether type reactive diluents may have a risk of skin sensitization.
For this reason, contact with the concentrated product should be avoided and the personal protective equipment specified in the exact SDS should be used.
When purchasing an Epoxy Reactive Diluent, chemical structure, functionality, epoxy equivalent weight, viscosity, amount of water, hydrolyzable chlorine, residual epichlorohydrin, color, and compatibility with the main epoxy resin should be considered together.
Companies planning to supply Epoxy Reactive Diluent from Ataman Kimya are recommended to confirm the current product and offer conditions by sharing the main resin type, target viscosity, required functionality, epoxy equivalent weight, hardener used, mechanical and chemical performance requirements, packaging and technical document needs.
