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Molecular Weight and Molecular Weight Distribution of Kraft Lignins

Published online by Cambridge University Press:  16 February 2011

Wolfgang Schmidl ,
Daojie Dong  and
Arthur L. Fricke
Wolfgang Schmidl
Affiliation:
University of Florida, Department of Chemical Engineering, Gainesville, FL 32611
Daojie Dong
Affiliation:
University of Florida, Department of Chemical Engineering, Gainesville, FL 32611
Arthur L. Fricke
Affiliation:
University of Florida, Department of Chemical Engineering, Gainesville, FL 32611
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Abstract

Kraft lignins are the lignin degradation products from kraft pulping. They are complex, heterogeneous polymers with some polar character. The molecular weight of kraft lignins greatly affect the physical properties of black liquors, and are of primary importance in separation from black liquor and in evaluating potential uses.

Several purified kraft lignins from slash pine were analyzed for number average molecular weight by vapor pressure osmometry (VPO), for weight average molecular weight by low angle laser light scattering (LALLS), and for the molecular weight distribution by high temperature size exclusion chromatography (SEC). The lignins were run in Tetrahydrofuran (THF), N, N-Dimethyl Formamide (DMF), DMF with 0.1M LiBr, and pyridine at conditions above the Theta temperature. Experimental methods are discussed.

The results show that VPO may be used to determine Mn for kraft lignins if the purity of the lignins and the identity of the impurities are known. LALLS can be used to determine Mw for kraft lignins if measurements are made at or above the Theta temperature of the lignin-solvent pair. SEC should be used at temperatures at, or above, the Theta temperature of the lignin-solvent pair. Size separation is highly dependent on the solvent used, and DMF is a much better solvent than THF for high temperature SEC. Future work using moment resolution procedures to derive an accurate calibration curve are also discussed.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 197: Symposium U – Materials Interactions Relevant to the Pulp, Paper and Wood Industries , 1990 , 21
Copyright
Copyright © Materials Research Society 1990

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References

Literature Cited

1. Gupta, P.R. and Goring, D.A.I., Can. J. Chem. 38, 270–279 (1960).Google Scholar
2. Benko, J., TAPPI 47 (8), 508–514 (1964).Google Scholar
3. Marton, J. and Marton, T., TAPPI 47 (8), 471–476 (1964).Google Scholar
4. Lindberg, J.J., Tylli, H., and –Majani, C., Paperi Ja Puu 46 (9), 521–526 (1964).Google Scholar
5. Brown, W., J. Appl. Poly. Sci. 11, 2381–2396 (1967).Google Scholar
6. Lin, S.Y. and Detroit, W.J., Ekman Day 4, 44–52 (1981).Google Scholar
7. Obiaga, T.I. and Wayman, M., Sven. Pappst. 76 (18), 699–703 (1973).Google Scholar
8. Kolpak, F.J., Cietek, D.J., Fookes, W., and Cael, J.J., J. Appl. Poly. Sci.: Appl. Poly. Symp. 37, 491–507 (1983).Google Scholar
9. Connors, W.J., Sarkanen, S., and McCarthy, J.L., Holzforsch. 34, 80–85 (1980).Google Scholar
10. Sarkarnen, S., Teller, D.C., Hall, J., and McCarthy, J.L., Macromol. 14, 426–434 (1981).Google Scholar
11. Moacanin, J., Felicetta, V.F., and McCarthy, J.L., J. Amer. Chem. Soc. 81, 2052–2054 (1959).Google Scholar
12. Forss, K. and Stenlund, B., Paperi Ja Puu 51 (1), 93–105 (1969).Google Scholar
13. Gupta, P.R. and McCarthy, J.L., Macromol. 1(3), 236–244 (1968).Google Scholar
14. Kim, H.-K., Hill, M.K., and Fricke, A.L., TAPPI J. 70 (12), 112–116 (1987).Google Scholar
15. Fricke, A.L., DOE Report No. DOE/CE/40606-T5 (DE88002991), 1987.Google Scholar
16. Fricke, A.L., DOE Report No. DOE/CE/40606-TI (DE84006996), 1983.Google Scholar
17. Dong, D.J. and Fricke, A.L., Presented at the 1990 MRS Spring Meeting, San Francisco, CA, 1990 (unpublished).Google Scholar
18. Kim, H.-K., Ph.D. Thesis, University of Maine, 1985.Google Scholar
19. Kim, H.-K. and Fricke, A.L., ”Number Average Molecular Weight of Kraft Lignin” (submitted for publication).Google Scholar
20. Chum, H.L., Johnson, D.K., Tucker, M.P., and Himmel, M.E., Holzforsch. 41, 97–108 (1987).Google Scholar
21. Pellenin, J. and Salkinoja-Salonen, M., J. Chromat. 328, 299–308 (1985); 332, 129–138 (1985).Google Scholar
22. Wagner, B.A., To, T., Teller, D.E., and McCarthy, J.L., Holzforsch. 40, 67–73 (1986).Google Scholar
23. Himmel, M.E., Oh, K.K., Sopher, D.W., and Chum, H.L., J. Chromat. 267, 249–265 (1983).Google Scholar