[ambar_018]

Hello!

I am trying to describe a polyurethane (made by mixing parts A and B) by the compounds of its soft and hard segments (see picture attached). I found online that the hard segments are composed of diisocyanates and a chain extender, and the soft segments of polyether or polyester polyol. Based on the safety datasheet (see picture attached), I could figure out the following:
 
-Diisocyanates: diphenylmethane-2,4'-diisocyanate & 4,4'-methylenediphenyl diisocyanate & diphenylmethane-4,4'-diisocyanate
-Chain extender:  3,5-dimethylthio-2,4-toluenediamine & 3,5dimethylthio-2,6-toluenediamine

But, I am unsure about the composition of the soft segments. I appreciate any help you can provide me.

Disclaimer: I am not a chemist not have I had any chemistry courses since high school.

[marquis]

The manufacturers usually have applications chemists who can help with this kind of problem, especially if you are a potential customer. They can give you the answers needed. 

[DrCMS]

The PU that would be formed by mixing A and B can not easily be described in the way you are trying. 
Part A is a hard segment. 
Part B contains hard and soft segments but they are not clearly defined.

Why do you need this?