روش‌های شناسایی ساختار شیمیایی پلیمر لیگنین

نوع مقاله: تالیفی

نویسندگان

1 دانشجو/ دانشگاه تربیت مدرس

2 عضو هیات علمی/ دانشگاه تربیت مدرس

چکیده

لیگنین دومین پلیمر طبیعی فراوان پس از سلولوز در دنیاست که به‌عنوان ماده‌ای ارزان، غیرسمی و
زیست‌تخریب‌پذیر، جایگزین مناسبی برای پلی‌ال‌های بر پایه نفت شناخته شده است. پژوهشگران تلاش فراوانی به‌منظور شناسایی ساختار شیمیایی لیگنین انجام داده‌اند. اما، همچنان مشکلات بسیاری در جایگزینی مونومرهای به‌دست آمده از نفت خام و به‌کار رفته در ساخت و سنتز مواد پلیمری، مانند پلی‌یورتان‌ها، با لیگنین وجود دارد. از مشکلات عمده در شناسایی این پلیمر طبیعی، نبود پروتکل‌های مشخص و استاندارد است. در این مقاله، مطالعه‌ای نظام‌مند به‌منظور شناسایی کمی گروه‌های عاملی لیگنین، با استفاده از فنون مختلف، مانند تیترکردن و طیف‌سنجی‌های 19FNMR ،31PNMR ،13CNMR ،1HNMR و UV-VIS انجام شده است. در ادامه، با بررسی مزایا و محدودیت‌های هر روش، شیوه‌های تعیین وزن مولکولی و خواص گرمایی لیگنین نیز بیان شده است.

کلیدواژه‌ها


عنوان مقاله [English]

Chemical Structure Characterization Methods for Lignin Polymer

نویسنده [English]

  • Mahdi Abdollahi 2
چکیده [English]

Lignin is the second most abundant natural polymer after cellulose in the world; and as a cheap, non-toxic and biodegradable material, it is a good alternative to the petroleum-based polyols. Despite researchers’ efforts to identify the structure of lignin, there are many problems which hinder lignin to be accepted as an appropriate monomer and a competitive alternative to the monomers derived from the crude oil for synthesis of polymers such as polyurethane. One of the major problems related to identification of the lignin structure is lack of well-defined protocols and standard. In this paper, a systematic study has been performed to quantitatively identify the functional groups present in the lignin structure using different techniques such as 1H NMR, 13C NMR, 31P NMR, 19F NMR and UV-VIS spectroscopies and titration. The advantages and limitations of each method havealso been discussed. Moreover, the molecular weight and thermal properties of lignin have been determined by a variety of methods.

کلیدواژه‌ها [English]

  • lignin
  • chemical structure characterization
  • titration
  • spectroscopy
  • molecular weight
1. Laurichesse S. and Avérous L., Chemical Modification ofLignins: Towards Biobased Polymers, Prog. Polym. Sci., 39,1266-1290, 2014.

2. Adler E., Lignin Chemistry-Past, Present and Future, Wood Sci. Technol., 11, 169-218, 1977.

3. Sarkanen K. and Ludwig. C, Lignins: Occurrence, Formation,Structure and Reactions, John Wiley and Sons, New York,1971.

4. Adler E. and Hernestam S., Estimation of Phenolic HydroxylGroups in Lignin. I. Periodate Oxidation of Guaiacol Compounds,

Anal. Chim. Acta, 9, 319-334, 1995.

5. Lai Z., Determination of Phenolic Hydroxyl Groups, Methodsin Lignin Chemistry, Springer-Verlag, Heidelberg, 423-434,1992.

6. Mansson P., Quantitative Determination of Phenolic and Total Hydroxyl Groups in Lignins, Holzforschung, 37, 143-146,

1983.

7. Lai Y.Z., Guo X.P., and Situ W., Estimation of Phenolic HydroxylGroups in Wood by a Periodate Oxidation Method, J.

Wood Chem. Technol., 10, 365-377, 1990.

8. Faix O., Grünwald C., and Beinhoff O., Determination of PhenolicHydroxyl Content of Milled Wood Lignins (MWL´s)

from Different Botanical Origins Using Selective Aminolysis,FTIR, 1H-NMR and UV Spectroscopy, Holzforschung, 46,425-432, 1992.

9. Zakis G., Functional Analysis of Lignins and Their Derivatives,Tappi, Atlanta, 1994.

10. Chen C.L., Dence C., and Lin S., Determination of CarbonylGroups, Methods in Lignin Chemistry, Springer-Verlag,Heidelberg,446-457, 1992.

11. Gosselink R., Abächerli A., Semke H., Malherbe R., Käuper P., and Nadif A., Analytical Protocols for Characterisation of

Sulphur-Free Lignin., Ind. Crops Prod., 19, 271–281, 2004.

12. Zeisel S., Über ein Verfahren Zum Quantitative Nachweis VonMethoxyl, Monatsh. Chem., 6, 989-996, 1885.

13. Mansouri N. and Salvadó J., Analytical Methods for DeterminingFunctional Groups in Various Technical Lignins, Ind.Crops Prod., 26, 116-124, 2007.

14. Thielemans W. and Wool R., Lignin Esters for Use in Unsaturated Thermosets: Lignin Modification and Solubility Modelling,Biomacromolecules, 6, 1895-1905, 2005.

15. Adilson R., Gonçalvesa U., and Maria L., Piassava Fibers (Attaleafunifera): NMR Spectroscopy of their Lignin, J. Braz.

Chem. Soc., 11, 491-494, 2000.

16. Granata A. and Argyropoulos D., 2-Chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholaan Reagent for the Accurate Determinationof the Uncondensed and Condensed Phenolic Moietiesin Lignins, J. Agric. Food. Chem., 43, 1538-1544, 1995.

17. Crestini C. and Argyropoulos D., Structural Analysis of WheatStraw Lignin by Quantitative 31P and 2D NMR Spectroscopy,

The Occurrence of Ester Bonds and a-O-4 Substructures, J.Agric. Food. Chem., 45, 1212-1219, 1997.

18. Barrelle M., A New Method for The Quantitative 19FNMRSpectroscopic Analysis of Hydroxyl Groups in Lignins, Holzforschung,47, 261–267, 1993.

19. Sevillano R., Mortha G., Barrelle M., and Lachenal. D, 19FNMR Spectroscopy for the Quantitative Analysis of Carbonyl

Groups in Lignins, Holzforschung, 55, 286–295, 2001.

20. Xia Z., Akim L., and Argyropoulos D., Quantitative 13C-NMR Analysis of Lignins with Internal Standards, J. Agric. Food.

Chem., 49, 3573-3578, 2001.

21. Gärtner A., Gellerstedt G. and Tamminen T., Determination ofPhenolic Hydroxyl Groups in Residual Lignin Using a Modified Uv Method, Nordic Pulp Pap. Res. J., 14, 163–170, 1999.

22. Evtuguin D., Domingues P., Amado F., Pascoal Neto C., and Correia A., Electrospray Ionization Mass Spectrometry As a

Tool for Lignins Molecular Weight Determination and StructuralCharacterisation, Holzforschung, 53, 525-528, 1999.

23. Bayerbach R., Nguyen V., Schurr U., and Meier D., Characterisationof the Water Insoluble Fraction from Fast Pyrolysis

Liquids (Pyrolytic Lignin) Part III. Molar Mass Characteristicsby SEC, MALDI-TOF-MS, LDI-TOF-MS and Py-FIMS,

J. Anal. Appl. Pyrolysis, 77, 95–101, 2006.

24. Hortling B., Turunen E., and Kokkonen P., Molar Mass and Size Distribution of Lignins, Handbook of Size Exclusion

Chromatography and Related Techniques, CRC, New Jersey,USA, 355-384, 2004.

25. Nassar M. and MacKay G., Mechanism of Thermal Decomposition of Lignin, Wood Fiber Sci., 16, 441-453, 1984.