Fumaric acid, first analysis

Polymerization Reaction. In order to demonstrate the success of the carboxylic acid-isocyanate reaction in the course of the polymerization, as opposed to the model systems, the polymers were examined by FTIR, NMR and element analysis. Hgiue 4a shows the infrared spectrum of a typical PEUAm at the end of the reaction, with fumaric acid as the chain extender (PEUFA). First of all, it can be seen that the characteristic peak associated with NCO, at about 2270 cm l, does not appear, indicating the completion of the isocyanate reaction. The peak at about 3325-3330 cm" 1 can be assigned to N-H groups which participate in hydrogen bonds (22,25). 

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