Hello Botros,

I believe you have this one in radar

ASTM D5523 - 15 

Standard Test Method for Polyurethane Raw Materials: Acidity by Argentometric Determination of Hydrolyzable Chlorine in Monomeric, Aromatic Isocyanates

5.1 This test method is suitable for research or for quality control to characterize TDI and MDI.

Regards

Amin

thank you Amin

Just a simple note which may help in your research project: Pure MDI has very little acidity; most commonly it has from 1 to 10 ppm HCl acidity, no more.

Determination of acidity of MDI (as percent HCl) is done by the cold method given in the attached link.

https://dowac.custhelp.com/app/answers/detail/a_id/5788/~/dow-polyurethanes---isonate-mdi-acidity-test-method

dear Dr Nizar 

MDI i used isn't pure MDI but mixture between 2,4 and 4,4 MDI

Botros S Meglaa

dear botros

This is my problem too.

could you tell me,if you found your answer.

best regards