Kinetic Studies of Metallocene-Catalyzed Copolymerization of Propene with 10-Undecene-1-ol Using In-Line FTIR Spectroscopy Karin Sahre, * Ulrich Schulze, Klaus-J. Eichhorn, Brigitte Voit Introduction The use of IR and Raman spectroscopy allows both the monitoring and analysis of various polymerization reac- tions. Especially the in-line attenuated total reflection (ATR)-FTIR spectroscopy is a very effective tool for providing insights into complex reaction pathways. For that purpose, the so-called ‘‘ReactIR’’ technology was developed, in which an FTIR spectrometer is directly connected with specific types of reactors for synthesis in order to monitor chemical reactions in situ via individually adapted ATR probes. The in-line monitoring system is able to detect changes in chemical structures and to determine reaction rates by the monitoring of relevant signals in the spectroscopic fingerprint mid infrared range (4 000–650 cm 1 ). [1–9] The continuous real-time generation of analytical data allows observing the chemical process at the best resolution per time unit. The changes in reaction parameters are directly identifiable and consequently it will be possible to take corresponding actions in real time. Moreover, temporary internal chemical reaction phenom- ena will become more transparent. Thus, information about the reaction mechanism and monomer conversion Full Paper The present study describes the quantitative monitoring of the metallocene-catalyzed copoly- merization of propene with 10-undecene-1-ol (UO) by in-line ATR-FTIR spectroscopy in order to obtain kinetic data. For the description of the time dependency of this copolymerization reaction a pseudo-first-order rate law was used. The apparent rate constant k app of the comonomer consumption could be determined by evaluation of the integral absorbances of characteristic IR bands of the double bond of UO and of special IR determined concentration profiles of that comonomer using chemometric tools. The apparent rate constants determined by the integral absorbances of the n C – –C band (stretching vibrations) range of 0.32–0.66  10 4 s 1 whereas evaluation of the absolute concentrations of the comonomer yields rate constants of 0.29–0.57  10 4 s 1 . Variations within the rate constants obtained from different experimental runs point to a certain complexity of the reaction and a significant dependence of the copolymerization on the exact poly- merization procedure. K. Sahre, U. Schulze, K.-J. Eichhorn, B. Voit Leibniz Institute of Polymer Research Dresden, Hohe Strasse 6, D-01069 Dresden, Germany Fax: þ49 351 4658284; E-mail: sahre@ipfdd.de Macromol. Chem. Phys. 2007, 208, 1265–1273 ß 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim DOI: 10.1002/macp.200700145 1265