Kinetic study of the solution polymerization of methacrylamide initiated with potassium persulfate using in situ Raman spectroscopy and band‐target entropy minimization

In this paper, the use of in situ Raman spectroscopy together with a novel multivariate data analysis method, band-target entropy minimization (BTEM), is discussed to monitor the solution polymerization of methacrylamide in aqueous medium. Although FTIR spectroscopy is a more popular spectroscopic technique for polymer characterization and in situ polymerization monitoring, Raman spectroscopy is selected over FTIR in the current study. This is because water has very strong and broad infrared absorption bands and thus masks most of the other infrared signals contributed from monomer and polymer. On the contrary, water has very weak Raman scattering and thus it does not interfere the other Raman signals. The polymerization was initiated with potassium persulfate (KPS). A series of experiments were carried out varying initial monomer concentration, initial KPS concentration, and polymerization temperature. In situ Raman spectroscopy was used to monitor the polymerizing mixture and measure the compositions. The collected reaction spectra were subjected to BTEM to elucidate the pure component spectra, and then determine the conversion of monomer. The conversion data was then used to obtain kinetic parameters for the polymerization. The rate of consumption of monomers was found to follow the expression R = k eff [I] 0.55 [M] 1.41 . The activation energy of the system was estimated at 121 kJ/mol.

[1]  Marc Garland,et al.  The Rh4(CO)12-catalyzed hydroformylation of 3,3-dimethylbut-1-ene promoted with HMn(CO)5. Bimetallic catalytic binuclear elimination as an origin for synergism in homogeneous catalysis. , 2003, Journal of the American Chemical Society.

[2]  M. Garland,et al.  Application of Band-Target Entropy Minimization to On-Line Raman Monitoring of an Organic Synthesis. An Example of New Technology for Process Analytical Technology , 2007 .

[3]  Marc Garland,et al.  Fourier transform Raman spectral reconstruction of inorganic lead mixtures using a novel band‐target entropy minimization (BTEM) method , 2003 .

[4]  M. Garland,et al.  Algebraic system identification for a homogeneous catalyzed reaction: application to the rhodium-catalyzed hydroformylation of alkenes using in situ FTIR spectroscopy , 2004 .

[5]  P. Dvornic,et al.  Kinetics and mechanism of the formation of poly[(1,1,3,3‐tetramethyldisiloxanyl)ethylene] and poly(methyldecylsiloxane) by hydrosilylation , 2007 .

[6]  F. Rius,et al.  Curing reaction of glycidylthioether resins: Kinetic model study by near infrared spectroscopy and multivariate curve resolution , 2006 .

[7]  B. Chu,et al.  Study of Thermal Polymerization of Styrene by Raman Scattering , 1981 .

[8]  Ayman D. Allian,et al.  Experimental Raman spectra of dilute and laser-light-sensitive [Rh4(CO)9(µ-CO)3] and [(µ4-η2-3-hexyne)Rh4(CO)8(µ-CO)2]. Comparison with theoretically predicted spectra , 2006 .

[9]  Sandro Ridella,et al.  Minimizing multimodal functions of continuous variables with the “simulated annealing” algorithmCorrigenda for this article is available here , 1987, TOMS.

[10]  A. Scranton,et al.  Kinetics of cationic photopolymerizations of divinyl ethers characterized using in situ Raman spectroscopy , 1996 .

[11]  D. Hunkeler.  Mechanism and kinetics of the persulfate-initiated polymerization of acrylamide , 1991 .

[12]  Marc Garland,et al.  Application of FT‐Raman and FTIR measurements using a novel spectral reconstruction algorithm , 2003 .

[13]  Stanley M. Angel,et al.  In situ cure monitoring of epoxy resins using fiber-optic raman spectroscopy , 1994 .

[14]  Wee Chew,et al.  Rhodium tetracarbonyl hydride: the elusive metal carbonyl hydride. , 2002, Angewandte Chemie.

[15]  Liangfeng Guo,et al.  A general method for the recovery of pure powder XRD patterns from complex mixtures using no a priori information: Application of band-target entropy minimization (BTEM) to materials characterization of inorganic mixtures , 2004 .

[16]  M. Garland,et al.  Spectral reconstruction of in situ FTIR spectroscopic reaction data using band-target entropy minimization (BTEM): application to the homogeneous rhodium catalyzed hydroformylation of 3,3-dimethylbut-1-ene using Rh4(CO)12 , 2003 .

[17]  Dong Kook Kim,et al.  Kinetics of acrylamide solution polymerization using potassium persulfate as an initiator byin situ IR , 2004 .

[18]  L. Campbell,et al.  Real-Time In Situ Monitoring of the Thermal Cure of a Bisphenol Cyanate: A View Toward Intelligent Processing , 1996 .

[19]  C. Hoyle,et al.  Influence of the alkene structure on the mechanism and kinetics of thiol–alkene photopolymerizations with real‐time infrared spectroscopy , 2004 .

[20]  D. Haddleton,et al.  In situ Fourier transform near infrared spectroscopy monitoring of copper mediated living radical polymerization , 2004 .

[21]  F. Rius,et al.  Reactivity of silicon‐based epoxy monomers as studied by near‐infrared spectroscopy and multivariate curve resolution methods , 2006 .

[22]  Jaan Laane,et al.  Kinetics of trifluorovinyl ether cyclopolymerization via Raman spectroscopy , 1998 .

[23]  E. Gulari,et al.  Raman and FTIR spectroscopy of polymerization: bulk polymerization of methyl methacrylate and styrene , 1984 .

[24]  S. Ng,et al.  Persulphate initiated polymerisation of methacrylamide—I: Kinetics and molecular weight dependences , 1976 .

[25]  J. R. Stevens,et al.  Raman scattering from polymerizing styrene. I. Vibrational mode analysis , 1981 .

[26]  A. Mahadevan-Jansen,et al.  Automated Method for Subtraction of Fluorescence from Biological Raman Spectra , 2003, Applied spectroscopy.

[27]  Wee Chew,et al.  Band-target entropy minimization (BTEM): An advanced method for recovering unknown pure component spectra. Application to the FTIR spectra of unstable organometallic mixtures , 2002 .

[28]  Peter Terwiesch,et al.  On the Number of Observable Species, Observable Reactions and Observable Fluxes in Chemometric Studies and the Role of Multichannel Integration , 1997 .

[29]  S. Mason,et al.  Bulk radical homo-polymerisation studies of commercial acrylate monomers using near infrared Fourier transform Raman spectroscopy , 1991 .

[30]  Stefan Keller,et al.  Monitoring of the polymerization of vinylacetate by near IR FT Raman spectroscopy , 1997 .

[31]  Marc Garland,et al.  Semi-Batch Homogeneous Catalytic In-Situ Spectroscopic Data. FTIR Spectral Reconstructions Using Band-Target Entropy Minimization (BTEM) without Spectral Preconditioning , 2002 .

[32]  C. E. SHANNON,et al.  A mathematical theory of communication , 1948, MOCO.

[33]  K. Sahre,et al.  Monitoring of chemical reactions during polymer synthesis by real‐time attenuated total reflection (ATR)–FTIR spectroscopy , 2006 .

[34]  Wee Chew,et al.  Band-target entropy minimization. A robust algorithm for pure component spectral recovery. Application to complex randomized mixtures of six components. , 2003, Analytical chemistry.