Method for the control of polycondensation or polyaddition reactions

摘要

The reaction monitoring involves a low-pressure attenuated total reflection cell in which an infrared measurement beam (1) is deflected by mirrors (2,3) into and out of a pref. zirconium dioxide crystal (4) in a stainless steel casing (5). The reaction prod. (7) flows through a narrow gap (9) along the wetted face (6) of the crystal between seals (8). The infrared absorption of each chemical group is measured at one or more wave numbers, and the temp. of the sample is found from comparison with a temp./absorption calibration curve, which is used for correcting the temperature dependence of the sample absorption spectra, using the measured sample temp.