| abstract |
Setting a target range of anhydride-amine stoichiometry in the reaction mixture; Combining the solvent, diamine, bis (ether anhydride), and optionally end capping agent to form the reaction mixture, the reaction mixture having a polyamic acid content; Analyzing the amine and anhydride end group content of the reaction mixture using near infrared vibration spectroscopy; Calculating the anhydride-amine stoichiometry; Comparing the calculated anhydride-amine stoichiometry with the target stoichiometry and, if necessary, the bis (ether) based on comparing the calculated anhydride-amine stoichiometry to the target stoichiometry. Anhydride) or a method for producing polyetherimide comprising adjusting the concentration of diamine. |