I have this polymer with some amino functionality, but I need to know how much functionality it has. I am given an amine number of 2.5-3.3, and a viscosity range of 1000-2500 cts. I wish I had the molecular weight. Do I have to know how much titrant and how much sample they used to get this number in order to do the conversion?
You can determine the equivalent weight by dividing (1000*56.1) by the amine number. Because the material is a polymer and all man made polymers have a polydispersity (best slightly greater than 1 to an arbitrarily large number), then only average molecular weights are relevant. The molecular weight influences viscosity, but the flexibility of the polymer also has a pronounced effect. Consult any polymer text book for more details.
I am assuming that the number you have is in meq/g (see for instance: http://www.huntsman.com/performance_products/Media%20Library/a_MC348531CFA3EA9A2E040EBCD2B6B7B06/Products_MC348531D0B9FA9A2E040EBCD2B6B7B06/Amines_MC348531D0BECA9A2E040EBCD2B6B7B06/Polyetheramines%20%20%20JE_MC348531D0E07A9A2E040EBCD2B6B7B06/Diamine%20products_MC348531D0EA1A9A2E040EBCD2B6B7B06/files/JEFFAMINE%20D-2000_US.pdf). Then there is ca. 330 g/eq. However, for epoxy reactions, there are two reactive groups so the epoxy based equivalent weight is half that. For curing with isocyanates, you can assume 1 reactive group (the second is usually neglected). Thus the equivalent weight is 330 g/eq or 165 g/eq. From this information alone you cannot determine functionality.
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