The formula design of high-performance polyurethane hardener is a complex and professional task, involving chemical reaction principles, raw material selection, formula balance, etc. Many aspects. The following is a detailed introduction to the formula of high-performance polyurethane hardener, including formula principles, selection of key ingredients, and formula examples.
High-performance polyurethane hardener formula
Polyurethane hardener is an additive used to improve the hardness, wear resistance and chemical resistance of polyurethane materials. High performance hardeners are typically used in applications requiring high hardness, good mechanical properties and excellent durability. This article will introduce in detail the formula design principle of high-performance polyurethane hardener and an example formula.
1. Principle of formula design
The design of high-performance polyurethane hardeners is based on the following principles:
- Reactivity matching: The hardener should have good reactivity with the polyurethane base material to ensure that it can fully participate in the reaction during processing and form a stable network structure.
- Compatibility: The hardener must have good compatibility with the polyurethane base material to avoid separation or precipitation during use.
- Weather resistance: High-performance hardeners should have good weather resistance and be able to maintain stable performance under various environmental conditions.
- Environmental requirements: Modern formulations tend to use low VOC (volatile organic compounds) and environmentally friendly raw materials.
2. Key ingredient selection
The main components of high-performance polyurethane hardener include:
- Isocyanate: As the basic component of polyurethane, high-performance hardeners usually use multifunctional isocyanates, such as MDI (diphenylmethane diisocyanate), TDI (toluene diisocyanate), etc.
- Polyol: Choose polyols with high reactivity, such as polyether polyols, polyester polyols, etc., to increase cross-linking density.
- Catalyst: Catalysts help accelerate the formation reaction of polyurethane. Commonly used catalysts include organotin, amine catalysts, etc.
- Auxiliaries: including plasticizers, fillers, antioxidants, stabilizers, etc., used to improve the performance of the final product.
3. Recipe example
The following is an example of a basic formula for a high-performance polyurethane hardener:
- Isocyanates: MDI (4,4′-diphenylmethane diisocyanate), 100 parts
- Polyol: Polyether polyol (hydroxyl value is approximately 56 mg KOH/g), 50 parts
- Catalyst: dimethylcyclohexylamine (DMCHA), 0.5 parts
- Plasticizer: Dioctyl phthalate (DOP), 10 parts
- Filler: Nanoscale silica, 5 parts
- Antioxidant: Antioxidant 1010, 0.5 part
- Stabilizer: UV absorber UV-P, 1 part
4. Formula calculation and adjustment
The formula calculation of high-performance polyurethane hardener needs to consider the ratio of black and white materials, that is, the ratio of isocyanate and polyol. The isocyanate index (NCO/OH index) is usually set at around 105% to ensure complete reaction and a certain excess of NCO groups, thereby increasing cross-linking density and hardness.
Based on previous data, the following formula can be used to calculate:
- S1 = Number of polyol formulas × hydroxyl value / 56.1 × 100
- S2 = Water formula amount – 9
- S3 = Formula amount of small molecule substances × functionality/molecular weight
- S = S1 + S2 + S3
- Required amount of isocyanate = (S × 42) / 0.30 × 1.05
5. Application cases
- High-Performance Coatings: In coating applications that require high hardness and wear resistance, high-performance polyurethane hardeners can significantly improve the surface hardness and scratch resistance of the coating.
- Sports venues: Polyurethane materials used in sports venues such as runways and basketball courts can improve the elasticity and durability of the material by adding high-performance hardeners.
- Industrial Flooring: In flooring applications such as factory floors, high-performance hardeners can enhance the hardness and chemical resistance of flooring materials.
6. Summary
The formulation design of high-performance polyurethane hardeners is a delicate process and needs to be customized according to specific application requirements. The above formula is only an example and needs to be adjusted according to actual conditions in actual applications. When designing formulations, in addition to focusing on ingredient selection, factors such as processing conditions and cost-effectiveness also need to be considered.
Please note that the above formula is only an example and should be adjusted according to specific needs and experimental results during actual application. Additionally, follow safety procedures and wear appropriate personal protective equipment when working with chemicals. If more detailed guidance is required, it is recommended to consult a professional chemical engineer or relevant technical consultant.
Extended reading:
T120 1185-81-5 di(dodecylthio) dibutyltin – Amine Catalysts (newtopchem.com)
DABCO 1027/foaming retarder – Amine Catalysts (newtopchem.com)
DBU – Amine Catalysts (newtopchem.com)
bismuth neodecanoate – morpholine
amine catalyst Dabco 8154 – BDMAEE
2-ethylhexanoic-acid-potassium-CAS-3164-85-0-Dabco-K-15.pdf (bdmaee.net)
