Kinetic Studies of Metallocene‐Catalyzed Copolymerization of Propene with 10‐Undecene‐1‐ol Using In‐Line FTIR Spectroscopy

Abstract

The present study describes the quantitative monitoring of the metallocene‐catalyzed copolymerization 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 kapp 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 ν 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 polymerization procedure.magnified image

Defined Comonomer Re‐Feeding During the Metallocene‐Catalyzed Copolymerization of 10‐Undecene‐1‐olate with Propene through FTIR In‐Line Monitoring

“…Figure 1 shows the corresponding curves. As expected, the comonomer content is continuously decreased after adding the catalyst solution 1. These results are the base for the experiments with re‐feeding of comonomer because the calculated integral absorbances are directly associated with the comonomer concentration at every measurement point.…”

“…The metallocene‐catalyzed copolymerization reaction was monitored using a ReactIR TM 4000 in‐line measuring system (Mettler‐Toledo) based on the well‐known ATR technique 1, 2, 11–16. For this, a special diamond ATR probe (Sentinel TM ) was fixed at the bottom of the autoclave.…”

“…In recent years, the metallocene‐catalyzed copolymerization of propene with polar monomers has been described, comprising the pre‐reaction of the comonomer with aluminum alkyls 1–9. The corresponding reaction pathway is demonstrated in Scheme .…”

“…The corresponding reaction pathway is demonstrated in Scheme . In our previous work,1 we focused on kinetic studies of this reaction using in‐line ATR‐FTIR spectroscopy monitoring. Hackmann und Rieger10 have already discussed the synthesis of functional propene copolymers with more uniform composition by using IR spectroscopy data to control the comonomer concentration during the copolymerization.…”

Copolymerization of 4-methyl-1-pentene with α,ω-alkenols

“…Polyethylene and polypropylene are the polyolefin resins with the largest commercial scale. It follows then that most researches on the synthesis of the functional polyolefin concern ethylene [4][5][6][7][8][9][10][11][12][13] and propylene [14][15][16][17][18] copolymerization. The investigation on the copolymerization of higher α-olefin with functional monomer was rather rare.…”