Because of its excellent performance, polyaspartic polyurea is
widely used in waterproof and anti-corrosion, flooring, adhesive
and other fields. However, many engineers will have such a
confusion when they just start to design coating formulations with
polyaspartic polyurea resin, how should the amount of polyaspartic
polyurea resin and curing agent be calculated? So today, we will
give you a detailed explanation of the methods involved.
To solve this problem, first we need to understand the reaction
principle of polyaspartic resin and curing agent: The secondary
amine group of polyaspartic polyurea resin and the isocyanate
curing agent react to form a polymer with urea bonds. Because of
the high bond energy of urea, the film-forming of polyaspartic
polyurea resin and isocyanate curing has excellent performance:
high strength, high wear resistance, high impact resistance,
excellent flexibility, excellent weather resistance and good
chemical resistance.
Equivalent value refers to the mass of resin required to provide 1
mol of reactive groups, which can be interpreted as the mass of
resin required to provide 1 mol of secondary amine group (-NH) in
polyaspartic ester resin. For example, F420 equivalent is 277g/mol.
The isocyanate base in isocyanates is usually expressed as a
percentage of isocyanate base mass (NCO%), and the isocyanate base
can also be expressed in terms of equivalents, which are defined as
the number of grams of isocyanate consumed by 1 gram of molecular
amine to produce the corresponding urea, and the relationship
between equivalents and percent isocyanate content is: equivalents
= 42/NCO%.
According to the principle of equivalence, 1 mol of -NH needs to
consume 1 mol of -NCO, in order to ensure adequate curing, the
curing agent is recommended to overdose 5% . Curing agent to HT-600
for example, NCO value of 23%, equivalent = 4200/23 ≈ 183 (g/mol),
then 100gF420 need to consume HT-600 can be calculated as: 100/277
* 1.05 * 183 ≈ 69.4.
The above is the calculation of the amount of resin and curing
agent in designing the formulation of polyaspartic polyurea
coating.
Feiyang has been specializing in the production of raw materials
for polyaspartic coatings for 30 years and can provide polyaspartic
resins, hardeners and coating formulations. Some of our
polyaspartic coating formulations: Polyaspartic Coating
Feel free to contact us: marketing@feiyang.com.cn
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Learn more polyaspartic knowledge: Polyaspartic FAQ
