You may be aware of this paper (amongst others) :

http://www.sciencedirect.com/science/article/pii/S0032386100000677

But if your chitosan is special in terms of Mw of crosslinking, there is nothing else but the experimental measurement of your own material. Data from the literature can only help comparing and having an idea of the range of expected values, but only the value of your own measurement will be accurate and representative of your material.

Alain

thnq