Application of FT-NIR spectroscopy for monitoring the kinetics of living polymerizations

Fourier-transform near infrared (FT-NIR) spectroscopy in combination with a fiber optic probe was successfully used to monitor the living cationic polymerization of isobutylene (IB) and the living anionic polymerization of ethylene oxide (EO) and butadiene (B). After the development of online monitoring techniques for the living anionic polymerizations of styrene (S) and isoprene in the near infrared range (NIR), methods were developed that allow to follow the polymerization of IB and S in the mid-infrared (MIR) range. It was believed that NIR could not be used for IB due to overlapping signals. In this paper we show that even in the NIR specific signals of the monomer can be used for monitoring conversion without using deconvolution methods in IB as well as EO and B polymerizations. In the case of EO a temperature dependent induction period was found with sec-butyllithium and the phosphazene base t-BuP4 as initiating system.

[1]  L. G. Bonner.  Vibration Spectra and Molecular Structure. III The Infrared Absorption Spectra of Cyclopropane and Ethylene Oxide , 1937 .

[2]  J. Linnett.  Infra‐Red and Raman Spectra of Polyatomic Molecules. V. Cyclopropane and Ethylene Oxide , 1938 .

[3]  G. Herzberg,et al.  Infrared and Raman spectra of polyatomic molecules , 1946 .

[4]  K. S. Kazanskii,et al.  Polymerization of ethylene oxide by alkali metal-naphthalene complexes in tetrahydrofuran , 1971 .

[5]  E. Condon,et al.  Vibration Spectra and Molecular Structure , 1991 .

[6]  Timothy E. Long,et al.  Determination of solution polymerization kinetics by near-infrared spectroscopy. 1. Living anionic polymerization processes , 1993 .

[7]  M. Möller,et al.  Polymerization of Ethylene Oxide with Alkyllithium Compounds and the Phosphazene Base “tBuP4” , 1996 .

[8]  M. Möller,et al.  Anionic polymerization of oxirane in the presence of the polyiminophosphazene base t-Bu-P4 , 1996 .

[9]  A. Molenberg,et al.  Use of polyiminophosphazene bases for ring-opening polymerizations , 1996 .

[10]  F. Bandermann,et al.  Metal-free anionic polymerization of methyl methacrylate , 1997 .

[11]  R. Storey,et al.  Real-time monitoring of carbocationic polymerization of isobutylene using in situ FTIR-ATR spectroscopy with conduit and diamond-composite sensor technology , 1998 .

[12]  J. Puskas,et al.  Mid-IR real-time monitoring of the carbocationic polymerization of isobutylene and styrene , 1998 .

[13]  S. Förster,et al.  Synthesis of PB-PEO and PI-PEO block copolymers with alkyllithium initiators and the phosphazene base t-BuP4. , 1999 .

[14]  R. Storey,et al.  Synthesis of Poly(styrene-b-isobutylene-b-styrene) Block Copolymers Using Real Time In Situ ATR-FTIR Monitoring , 1999 .

[15]  H. Schmalz,et al.  ABC triblock copolymers with crystalline end blocks and their use as thermoplastic elastomers , 2001 .

[16]  Stephen Z. D. Cheng,et al.  Phase structures and morphologies determined by self-organization, vitrification, and crystallization: confined crystallization in an ordered lamellar phase of PEO-b-PS diblock copolymer , 2001 .

[17]  F. Schipper,et al.  Poly(ethylene oxide-b-isoprene) Diblock Copolymer Phase Diagram , 2001 .