Obtaining chain length dependent termination rate coefficients via thermally initiated reversible addition fragmentation chain transfer experiments current status and future challenges

Theis, A., Stenzel, M. H., Davis, T. P., & Barner-Kowollik, C. (2006) Obtaining chain length dependent termination rate coefficients via thermally initiated reversible addition fragmentation chain transfer experiments current status and future challenges. In Matyjaszewski, K. (Ed.) ACS Symposium Series.

View at publisher

Abstract

The reversible addition fragmentation chain transfer (RAFT) process can be utilized in conjunction with rate of polymerization measurements to accurately map the chain length dependence of the termination rate coefficient. This novel approach was originally applied to styrene polymerization and has been termed the RAFT chain length dependent termination (RAFT-CLD-T) method. The RAFT-CLD-T technique is discussed in the context of the prerequisite analysis parameters as well as the choice of RAFT agent. In the present contribution we critically compare the data obtained via RAFT-CLD-T thus far for the monomers styrene (Sty), methyl methacrylate (MMA), methyl acrylate (MA), butyl acrylate (BA), dodecyl acrylate (DA), and vinyl acetate (VAc). For monomers with relatively low reactivity propagating radicals (MMA), a strong chain length dependence of kt in the small chain length regime was observed, indicated by a relatively high α value (in the frequently used expression k t i,i = kt 0·l -α). With increasing chain length, the α value is continuously decreasing, caused by a slow transition from translational diffusion to segmental diffusion as predicted by the composite model of chain length dependent termination. For monomers with higher reactivity propagating radicals (MA, VAc), a linear dependence of kt with chain length was observed (α = 0.36 for MA and 0.09 for VAc). Within the acrylate class, an interesting influence of the side chain was found. In the small chain length regime, α is increasing with increasing length of the side chain from 0.36 in case of MA to 1.2 in DA, which may be attributed to an increased shielding of the polymeric radical. At longer chain lengths, the α value of MA is significantly higher than those for BA and DA, where a is strongly decreasing with increasing chain length. This may indicate a different flexibility and coil structure of MA compared to BA and DA. In general, the acrylates display significantly higher a values in the long chain region than MMA and VAc, which we assign to the presence of mid-chain radicals. The data obtained via three dimensional simultaneous mapping of the chain length and conversion dependence of kt (3D-RAFT-CLD-T) for MA and VAc are also highlighted. © 2006 American Chemical Society.

Impact and interest:

4 citations in Scopus
Search Google Scholar™

Citation counts are sourced monthly from Scopus and Web of Science® citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

ID Code: 99135
Item Type: Book Chapter
Additional Information: Cited By :4
Export Date: 5 September 2016
CODEN: ACSMC
Correspondence Address: Barner-Kowollik, C.; Centre for Advanced Macromolecular Design, School of Chemical Engineering and Industrial Chemistry, University of New South Wales, Sydney, NSW 2052, Australia; email: camd@unsw.edu.au
References: Barner-Kowollik, C., Buback, M., Egerov, M., Fukuda, T., Goto, A., Olaj, O.F., Russell, G.T., Zetterlund, P.B., (2005) Prog. Polym. Sci, 30, pp. 605-643; Buback, M., Egorov, M., Kaminsky, V., Olaj, O.F., Russell, G.T., Vana, P., Zifferer, G., (2002) Macromol. Chem. Phys, 203, pp. 2570-2582; Vana, P., Davis, T.P., Barner-Kowollik, C., (2002) Macromol. Rapid Commun, 23, pp. 952-956; Feldermann, A., Stenzel, M.H., Davis, T.P., Vana, P., Barner-Kowollik, C., (2004) Macromolecules, 37, pp. 2404-2410; Theis, A., Feldermann, A., Charton, N., Stenzel, M.H., Davis, T.P., Barner-Kowollik, C., (2005) Macromolecules, 38, pp. 2595-2605; Junkers, T., Theis, A., Buback, M., Davis, T.P., Stenzel, M.H., Vana, P., Barner-Kowollik, C., (2005) Macromolecules, 38, pp. 9497-9508; Theis, A., Feldermann, A., Charton, N., Davis, T.P., Stenzel, M.H., Barner-Kowollik, C., (2005) Polymer, 46, pp. 6797-6809; Johnston-Hall, G., Theis, A., Monteiro, M., Davis, T.P., Stenzel, M.H., Barner-Kowollik, C., (2005) Macromol. Chem. Phys, 206, pp. 2047-2053; Theis, A., Davis, T.P., Stenzel, M.H., Barner-Kowollik, C., (2006) Polymer, , in press; Barner-Kowollik, C., Quinn, J.F., Nguyen, T.L.U., Heuts, J.P.A., Davis, T.P., (2001) Macromolecules, 34, pp. 7849-7857; It is important to note that only an addition rate coefficient of infinity for the addition of propagating radicals, kβ, to the initial RAFT agent would lead to the molecular weight evolution starting with chain length one. In practice, all RAFT polymerization display some degree of hybrid behaviour, but in several cases the ratio of kp to k β is so favourable that very limited hybrid behaviour is observed. For a detailed description of these effects and the consequences for RAFT-SP-PLP see ref.5Theis, A., Davis, T.P., Stenzel, M.H., Barner-Kowollik, C., (2005) Macromolecules, 38, pp. 10323-10327; Buback, M., Huckstein, B., Kuchta, F.-D., Russell, G.T., Schmidt, E., (1994) Macromol. Chem. Phys, 195, pp. 2117-2140; Charton, N., Feldermann, A., Theis, A., Davis, T.P., Stenzel, M.H., Barner-Kowollik, C., (2004) J. Polym. Sci. Polym. Chem, 42, pp. 5170-5179; Beuermann, S., Buback, M., Davis, T.P., Gilbert, R.G., Hutchison, R.A., Olaj, O.F., Russell, G.T., van Herk, A.M., (1997) Macromol. Chem. Phys, 198, pp. 1545-1560; McLeary, J.B., Calitz, F.M., McKenzie, J.M., Tonge, M.P., Sanderson, R.D., Klumperman, B., (2005) Macromolecules, 38, pp. 3151-3161; Buback, M., Busch, M., Kowollik, C., (2000) Macromol. Theory Simul, 9, pp. 442-542; Buback, M., Egorov, M., Feldermann, A., (2004) Macromolecules, 37, pp. 1768-1776; de Kock, J.B.L., van Herk, A.M., German, A.L., (2001) J. Macromol. Sci., Polym. Rev, C41, pp. 199-252; de Kock, J.B.L., (1999), PhD Thesis, Technische Universiteit Eindhoven, ISBN 90-386-2701-7Willemse, R.X.E., van Herk, A.M., Panchenko, E., Junkers, T., Buback, M., (2005) Macromolecules, 38, pp. 5098-5103; Friedman, B., O'Shaughnessy, B., (1993) Macromolecules, 26, p. 5726; Karatekin, E., O'Shaughnessy, B., Turro, N.J., (2002) Macromol. Symp, 182, p. 81; Britton, D., Heatley, F., Lovell, P.A., (1998) Macromolecules, 31, pp. 2828-2837; Heuts, J.P.A., Russell, G.T., (2006) Europ. Polym. J, 42, pp. 3-20; Buback, M., Junkers, T., Vana, P., (2005) Macromol. Rapid Commun, 26, pp. 796-802; Smith, G. B.; Russell, G. T.; Yin, M.; Heuts, J. P. A Europ. Polym. J. 2005, 41, 225-230Fischer, H., Radom, L., (2001) Angew. Chem. Int. Ed, 40, pp. 1340-1371; Moad, G., Rizzardo, E., Solomon, D.H., Beckwith, A.L.J., (1992) Polym. Bull, 29, pp. 647-652; Willemse, R.X.E., Staal, B.B.P., van Herk, A.M., Pierik, S.C.J., Klumperman, B., (2003) Macromolecules, 36, pp. 9797-9803; Szablan, Z., Ah Toy, A., Davis, T.P., Hao, X., Stenzel, M.H., Barner-Kowollik, C., (2004) J. Polym. Sci. Polym. Chem, 42, pp. 2432-2443; Theis, A., Stenzel, M.H., Davis, T.P., Coote, M.L., Barner-Kowollik, C., (2005) Aust. J. Chem, 58, pp. 437-441; Coote, M.L., Henry, D.J., (2005) Macromolecules, 38, pp. 5774-5779
ISBN: 9780841239913
ISSN: 00976156
Divisions: Current > Schools > School of Chemistry, Physics & Mechanical Engineering
Current > Institutes > Institute for Future Environments
Current > QUT Faculties and Divisions > Science & Engineering Faculty
Deposited On: 22 Sep 2016 04:50
Last Modified: 26 Sep 2016 04:57

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page