Diisocyanate DI

Covestro Desmodur 44C Pure MDI

Product introduction
DESMODUR 44C is a 4,4'-diphenylmethane diisocyanate monomer with a molecular weight of 250 and is a colorless to pale yellow solid at room temperature. This product is mainly used in the production of polyurethane products.

sampling
During the sampling process, prevent the product from coming into contact with water vapor.

Specification

Property	Value	Unit of measurement	Method
2,4'-MDI content	≤1.8	%	20110367601-92
Hydrolyzed chloride content	≤50	ppm	2011-0339304-95
Dimer content*	≤0.1	%	2012-0346901-92

典型性质

Property	Value	Unit of measurement	Method
Purity (molecular weight 250)	≥99.5	%	2011-0248603-94
NCO content (theoretical value)	33.6	%	-
Phenyl isocyanate content	≤10	ppm	2011-0339304-95
Viscosity (40℃)	0.1	mPa.s	2011-0313703-95
Density (40℃)	1.19	g/cm³	DIN 51757
Specific heat (cp)	1.39	kJ/kg.K
heat of dissolution	102	J/g

Package

DESMODUR 44C is available in two ways:
- Liquid (tank truck)
- Solid state (drums, net weight 225kg)

Storage

Recommended storage temperature (℃)	<5 (solid), 43±2 (liquid)
Shelf life	≤3 months (solid state), ≤3 weeks in a storage tank (liquid state) if stored in a closed, water-repellent state

Action suggestion
Like all isocyanates, DESMODUR 44C is very sensitive to water and reacts with water to produce insoluble urea and carbon dioxide. In a closed container, the carbon dioxide produced can cause a dangerous rise in container pressure.
DESMODUR 44C is exposed to air, especially in sunlight, which will accelerate its yellowing. It is therefore recommended to store liquid DESMODUR 44C in a dry nitrogen atmosphere. Yellowing generally does not affect the workability of the product.
DESMODUR 44C is heat sensitive and will form dimers. Solid DESMODUR 44C is more prone to dimerization at room temperature than liquid at 45℃. Therefore, solid products need to be stored below 5°C and melt gradually and rapidly before use. Although the product dimerization rate decreases with decreasing temperature, stability is still limited even below 5°C.
DESMODUR 44C in solid state needs to be heated to ≥70°C for melting. This process will increase the formation of insoluble dimers, and may also deform the barrel due to the increase in temperature and pressure.