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Crystallization of Liquid DGEBPA and
DGEBPF Epoxy Resins
Liquid DGEBPA epoxy resins and the liquid DGEBPF epoxy resins are supercooled liquids at
Remedies and Prevention
room temperature. That is, they are solids at room temperatures but normally remain liquid
below their solidification temperature. They supercool because the crystallization process
is slow at ordinary temperatures and they do not readily form the seed crystals that are
required for solidification to occur. As one increases the average molecular weight, higher
molecular weight species and isomers increase. These isomers and higher molecular weight
species reduce the tendency for crystal formation and growth.
Diluents and modifiers generally increase the rate of crystal formation and growth. Other
additives, such as pigments, fillers and wetting agents, can also affect the rate of crystal
formation and growth. Generally, if one prevents the introduction of seed crystals into a resin
handling system, crystallization will be a rare event unless one is handling high purity resins.
Crystallization of low molecular weight, high purity BPA based resins has been observed,
Low Molecular Weight
specifically with EPON鈩? Resins 825 and 826. EPON Resin 828 is generally thought to be
DGEBPA Resins
resistant to crystallization, though the use of some viscosity modifiers leads to increased
crystallization tendencies. EPON Resin 830 is often used as the base for low viscosity mod-
ified resins to deter any crystallization tendency. The lower viscosity resin blends containing
BGE (HELOXY鈩? Modifier 61) are the least resistant to crystallization whereas CGE (HELOXY
Modifier 62) is the most resistant. DGEBPA crystals melt in the range of 45 to 50掳 C/113 to 122 掳F.
EPON Resin 824 is a DGEBPA resin chemically modified to reduce viscosity to the 40 to 70
Chemcially Modified
poise range. It has a greatly reduced tendency to crystallize and can be used in many
DGEBPA Resins
applications that use EPON Resin 826. It does sacrifice some chemical resistance and
would need to be evaluated in any replacement usage.
E P I KOT E 鈩? EPON鈩? EPI-CURE鈩? EPI-REZ鈩? H E LOX Y 鈩? C A R D U R A鈩? V E O VA鈩?
SC:2365-01 / Crystallization of Liquid DGEBPA and DGEBPF Epoxy Resins Page 2
DGEBPF Resins EPON Resin 862 is capable of crystallization. EPON Resin 862 is slow to nucleate and growth
after nucleation is slow. The typical result is a lower layer or a slurry of crystals. If EPON 862 is
diluted with BGE (HELOXY Modifier 61), crystallization can occur more readily. Crystals of
DGEBPF have a very high melting point, 80-85 掳C, making reconstitution more difficult than
with DGEBPA resins.
Several products have been developed that are blends of EPON Resin 862 and 828. These
materials show good resistance to crystallization and have viscosities in the EPON Resin
826 range. Addition of EPON Resin 862 to EPON Resins 826 and 828 does improve crystal-
lization resistance. Blends of EPON Resin 828 containing 40% to 80% EPON Resin 862 have
not been observed to crystallize under laboratory or field conditions.
Recommendations to Resin Storage: Crystallization of DGEBPA resins is possible in the temperature range between
Customers Experiencing the glass transition point (-10 to -20 掳C/14 to -4 掳F) and the crystalline melting point (45 to 50
Crystallization 掳C/113 to 122 掳F). Storage temperatures greater than 122 掳F (50 掳C) should be used. DGEBPA
resins modified with HELOXY Modifiers 7, 8, 9, and 61 show a greater tendency to crystallize
and should not be stored cold. If aromatic modifiers are acceptable, CGE (HELOXY Modifier 62)
has been shown to give more resistance to crystallization than the aliphatic HELOXY Modifiers.
Crystallization of DGEBPF resins is possible in the temperature range between the glass
transition point (-10 to -20 掳C/14 to -4 掳F) and the crystalline melting point (80 to 85 掳C/176 to
185 掳F). Storage temperatures no greater than necessary should be used. DGEBPF resins
modified with HELOXY Modifiers 7, 8, 9, and 61 show a greater tendency to crystallize and
should not be stored cold. If aromatic modifiers are acceptable, CGE (HELOXY Modifier 62)
has been shown to give more resistance to crystallization than the aliphatic HELOXY Modifiers.
For DGEBPA resins that have crystallized: Heat the tank, drum, or pail to 140 掳F (60 掳C) for
at least one hour to melt any crystalline material. Ensure that all associated piping, pumps,
etc. are also heated similarly. This will remove any crystals from their system that could
nucleate additional crystal growth. If heated storage of resins is practiced, temperatures
greater than 122 掳F (50 掳C) should be used.
For DGEBPF resins that have crystallized: Heat the tank, drum, or pail to 194 掳F (90 掳C) for at
least one hour to melt any crystalline material (CAUTION! Any additional materials that
have been added to the resin may be adversely affected by these temperatures, hazardous
polymerization or decomposition may result). Ensure that all associated piping, pumps,
etc. are also heated similarly. This will remove any crystals from the system that could
nucleate additional crystal growth. If the resin is stored heated, the lowest effective tem-
perature should be used.
EPON Resin 824 is a crystallization resistant resin with a viscosity in the EPON Resin 826
range and may be worthy of evaluation as a replacement of 828 and 826. The use of
HELOXY Modifiers with EPON Resin 824 will adversely affect its inherent crystallization
resistance and is not recommended.
Resolution Performance Products
P.O. Box 4500
Houston, Texas 77210-4500
For product prices, availability, or order placement,
call our toll-free customer service number at:
1.877.859.2800
For sales in North and South America outside the United States, call:
1.832.366.2365
For literature and technical assistance,
visit our website at:
www.resins.com
SAFETY & HANDLING
These products are capable of producing adverse health effects ranging from minor skin irritation to serious systemic effects.
Exposure to these materials should be minimized and avoided, if feasible, through the observance of proper precautions, use
of appropriate engineering controls and proper personal protective clothing and equipment, and adherence to proper handling
procedures. None of these materials should be used, stored, or transported until the handling precautions and recommenda-
tions as stated in the Material Safety Data Sheet (MSDS) for these and all other products being used are understood by all
persons who will work with them. Questions and requests for information on Resolution Performance Products LLC (鈥淩PPLLC鈥?)
products should be directed to your RPPLLC sales representative, or the nearest RPPLLC sales office. Information and MSDSs
on non-RPPLLC products should be obtained from the respective manufacturer.
WARRANTY
NOTHING CONTAINED HEREIN CONSTITUTES AN OFFER FOR THE SALE OF ANY PRODUCT. ALL PRODUCTS SUPPLIED BY
RESOLUTION PERFORMANCE PRODUCTS LLC (鈥淩PPLLC鈥?) ARE SUBJECT TO THE TERMS AND CONDITIONS OF THE APPLI-
CABLE SALES CONTRACT AND NOTHING CONTAINED HEREIN SHALL AMEND OR MODIFY ANY SUCH CONTRACT. SUBJECT
TO THE FOREGOING, RPPLLC WARRANTS ONLY THAT ITS PRODUCTS WILL MEET SPECIFICATIONS SET FORTH IN THE
APPLICABLE SALES CONTRACT. RPPLLC MAKES NO OTHER WARRANTIES, EITHER EXPRESS OR IMPLIED, WITH RESPECT
TO ITS PRODUCTS OR THE RESULTS TO BE OBTAINED FROM THE USE THEREOF, OR WITH RESPECT TO ANY INFORMATION
PROVIDED BY RPPLLC, INCLUDING WITHOUT LIMITATION THAT ANY PRODUCT WILL BE MERCHANTABLE OR FIT FOR ANY
PARTICULAR PURPOSE OR THAT THE USE OF ANY PRODUCT OR INFORMATION PROVIDED BY RPPLLC WILL NOT INFRINGE
ANY PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS. ALL SUCH WARRANTIES ARE HEREBY DISCLAIMED AND EXCLUDED.
漏 2001 Resolution Performance Products LLC. All rights reserved. SC:2365-01
Printed in the U.S.A. 07/01
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