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4,4'-methylene-bis(N-sec-butylaniline) UNILINK 4200 chain extender

4,4'-methylene-bis(N-sec-butylaniline) UNILINK 4200 chain extender

Product Details


Formula :  C21H30N2


UNILINK 4200 is a unique aromatic diamine as a chain extender for polyurethane elastomers. As a 2-functional diamine, UNILINK 4200 builds linear polymer networks, allowing the polyurethane formulator to control the degree of cross-linking by the addition of higher functional polyols. 

The reactivity of UNILINK 4200 diamine is much lower than other aromatic amines and this low reactivity allows UNILINK 4200 diamine to be used as an effective curing agent in both TDI and MDI formulations. Polymers cured with UNILINK 4200 diamine generally exhibit longer pot lives and lower hardness with improved strength, adhesion, impact resistance and low temperature properties.
Polyurethane foam systems also benefit from the use of UNILINK 4200 diamine. TDI and MDI-based slabstock and moulded flexible foams can show improved strength and load-bearing properties often at significantly lower foam densities while PUR and PIR rigid foam formulations demonstrate improved dimensional stability, flow and adhesion. The use of UNILINK 4200 diamine in rigid and flexible foam systems has little effect on reaction kinetics or foam rise.

Technical Data 


 Dark Amber Liquid

 Specific Gravity at 60°F (16°C)


 Density, lb./US gallon


 Flash Point, PMCC, °F (°C)

 350 (177)

 Viscosity at 100°F (38°C), cps


 Viscosity at 212°F (100°C), cps


 Water content, wt.ppm


 Toxicity, LD5 0, mg/kg. (Acute oral, rat)


 Ames Test


 Molecular Weight


  Equivalent Weight


 Apparent Hydroxyl Number



1. Safe, easy to handle liquid
2. Longer pot lives
3. Low toxicity -- Ames negative
4. Improved flow and adhesion
5. Low moisture sensitivity
6. Amine-cured MDI pre-polymers
7. Compatible with a wide range of polyols,co-curatives and all other polyurethane chemicals
Room temperature curable systems
8. Rigid foams: improvements in compressive,strength, dimensional stability and friability,a higher percentage of closed cells and a lower K-factor
9. Flexible TDI-based foams: lower density, higher strength and higher load bearing properties.
10. Flexible MDI-based foams: lower density and lower hardness with improved strength.


UNILINK 4200 diamine enjoys commercial success in rigid and flexible foams, coatings, adhesives, sealants and elastomers. Typical use levels are between 1 and 5 parts per hundred polyol (php). This novel diamine has also found use in spray polyurea formulations and a range of metal and concrete repair compounds.

Package,Storage and transportation:

Package: 200kg/barrel       

Storage: Keep materials in the room which is dry and ventilate ration; Avoid direct sunlight when transportation, avoid collisions and pay attention to fire;

Shelf time:12 Months

Transportation:Transport as DG Goods

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Qingdao Hengke Fine Chemicals Co.,Ltd