Chemical Functionalization of Xylan - American Chemical Society

sulfating agents alone or in combination with alcohols, amines or chlorinated hydrocarbons as reaction media (9). The reaction of beech wood xylan in ...
0 downloads 0 Views 1MB Size
Chapter 20

Chemical Functionalization of Xylan: A Short Review 1

1

Thomas Heinze , Andreas Koschella , and Anna E b r i n g e r o v á

2

1

Department of Chemistry (FB9), Bergische University of Wuppertal, Gauss Strasse 20, D-42097 Wuppertal, Germany Institute of Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava, SK-842 38, Slovakia

Downloaded by YORK UNIV on November 25, 2012 | http://pubs.acs.org Publication Date: October 7, 2003 | doi: 10.1021/bk-2004-0864.ch020

2

Typical functionalization reactions of xylan are reviewed. Moreover, comments about the analytical characterization of the xylan derivatives are given and some structure-property relationships are discussed.

The hemicellulose xylan belongs to the most abundant biopolymers present in wood and other plants such as grasses, cereals, and herbs. The xylan structure is rather complex. Depending on the natural source of the xylan, varying contents of glucose, xylose, mannose, galactose, arabinose, fucose, glucuronic acid, and galacturonic acid can be found. The backbone consists mainly of P~ l - » 4 - l i n k e d xylose units (7). Recently, xylan gains increasing importance as basis for new biopolymeric materials and functional polymers by chemical modification reactions. Moreover, agricultural wastes like cobs, blades, leaves are always available and interesting raw-products. In the present article, important functionalization methods for the preparation of xylan derivatives are discussed. In addition, examples for the structure analysis and applications are given.

Xylan esters Carboxylic acid esters of xylan are prepared under typical conditions used for polysaccharide esterification, i.e., activated carboxylic acid derivatives are allowed to react with the polymer both heterogeneously and homogeneously (Figure 1). The heterogeneous esterification of oakwood sawdust and wheat bran

312

© 2004 American Chemical Society

In Hemicelluloses: Science and Technology; Gatenholm, P., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2003.

Downloaded by YORK UNIV on November 25, 2012 | http://pubs.acs.org Publication Date: October 7, 2003 | doi: 10.1021/bk-2004-0864.ch020

313 hemicelluloses (extracted with alkaline media) with an excess of octanoyl chloride under different conditions including the use of bases and co-solvents was described (2). The conversion was characterized by the weight increase of the products and the ester content by a saponification method. A solid esterified material and a liquid fraction were isolated after a solvent-free reaction. The liquid fraction was separated into an insoluble part (acetylated cellulose) and soluble hemicellulose and lignin. Moreover, the values of the degree of substitution (DS) of the products after fractionation steps showed that products of high DS are soluble in the reaction medium and, therefore, DS values of solubilized parts are higher compared to the non-dissolved material. The conversion of hemicellulose and wood is accompanied by polymer degradation induced by acidic hydrolysis due to the HC1. The amount of liquefied fraction is diminished in the presence of pyridine.

ONa

Xyl—OH



Xyl—OS0 Na 3

n

R= Alkyl group

Xy|= — " ^ V ^ — \ Sulfating agent= H>S0 HOA-^^\—0-.. SQj

4

OH

Figure

CISQH

1. Introduction of ester groups into xylan.

The homogeneous acylation of the hemicellulose is mostly carried out in the solvent A^A^-dimethylformamide (DMF) in combination with LiCl. Hemicellulose extracted from poplar wood chips was acylated with various carboxylic acid chlorides in D M F / L i C l applying triethylamine and 4-N,Ndimethylaminopyridine (DMAP) as base and catalyst (3, Table 1). Depending on

In Hemicelluloses: Science and Technology; Gatenholm, P., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2003.

314 the molar ratio of acyl chloride and anhydroxylose unit, DS values in the range from 0.32 to 1.51 were obtained under moderate reaction conditions (temperature < 7 5 ° C , time up to 45 min).

Table 1: Conditions and degree of substitution (DS) of esterified hemicellulose.

Downloaded by YORK UNIV on November 25, 2012 | http://pubs.acs.org Publication Date: October 7, 2003 | doi: 10.1021/bk-2004-0864.ch020

Molar ratio" Acetyl Butyryl Octanoyl Decanoyl Decanoyl Stearoyl Stearoyl Stearoyl Oleoyl Oleoyl

Product

Conditions

Carboxylic acid chloride

3:1 3:1 3:1 2:1 3:1 2:1 3:1 3:1 2:1 3:1

Temp. rc) 45 75 75 65 75 65 75 75 65 75

Time (min) 30 35 40 30 40 30 40 45 30 40

TEA"

DS

4

104.08 104.08

102.50 102.50

73.39 74.02

73.39 73.64

84.39 74.62

68.61 77.29

65.78 63.80

104.05 104.05 203.73

102.48 102.48

73.56 74.15

73.56 74.15

84.28 74.54

68.51 77.22

65.75 63.80

l->3

Xylan 3-O-substituted 4-O-substituted

Br oxidized derivative 2

3-O-substituted 4-O-substituted CO

In Hemicelluloses: Science and Technology; Gatenholm, P., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2003.

324 per repeating unit suitable for chemical functionalization and supramolecular structure formation make the polymers available by functionalization reactions an interesting class of polymeric materials whose attractiveness is expected to rise in the future.

References 1.

Downloaded by YORK UNIV on November 25, 2012 | http://pubs.acs.org Publication Date: October 7, 2003 | doi: 10.1021/bk-2004-0864.ch020

2.

3.

Ebringerová, A . ; Heinze, Th. Xylan and xylan derivatives - biopolymers with valuable properties, 1. Macromol. Rapid Commun. 2000, 21, 542-556. Thiebaud, S.; Borredon, M . E . Analysis of the liquid fraction after esterification of sawdust with octanoyl chloride - production of esterified hemicelluloses. Biores. Technol. 1998, 63, 139-145. Sun, RunCang; Fang, J.M.; Tomkinson, J.; Hill, C.A.S. Esterification of hemicelluloses from poplar chips in homogeneous solution of N , N dimethylformamide/Lithium chloride. J. Wood Chem. Technol. 1999, 19(4), 287-306.

4.

Sun, R.C.; Fang J. M . ; Tomkinson, J. Stearoylation of hemicelluloses from wheat straw. Polym. Degrad. Stab. 2000, 67, 345-353. 5. Fang, J. M . ; Sun, R. C.; Tomkinson, J.; Fowler, P. Acetylation of wheat straw hemicellulose B in a new non-aqueous swelling system. Carbohydr. Polym. 2000, 41, 379-387. 6. Sun, Runcang; Sun, X . F.; Bing, X . Succinoylation of Wheat Straw Hemicelluloses with a Low Degree of Substitution in Aqueous Systems. J. Appl. Polym. Sci. 2002, 83, 757-766. 7. Vincendon, M . Xylan derivatives: aromatic carbamates. Makromol. Chem. 1993, 194, 321-328. 8. Okamoto, Y . ; Noguchi, J.; Yashima, E . Enantioseparation on 3,5-dichloroand 3,5-dimethylphenylcarbamates of polysaccharides as chiral stationary phases for high-performance liquid chromatography. React. Functional Polym. 1998, 37, 183-188. 9. Klemm, D.; Philipp, B.; Heinze, T.; Heinze, U . ; Wagenknecht, W. Comprehensive Cellulose Chemistry; Wiley-VCH: Weinheim, 1998. 10. Philipp, B.; Nehls, I.; Wagenknecht, W. C - N . M . R . spectroscopic study of the homogeneous sulphation of cellulose and xylan in the N O - D M F system. Carbohydr. Res. 1987, 164, 107-116. 13

2

4

11. Yamagaki, T.; Tsuji, Y . ; Maeda, M . ; Nakaknishi, H . N M R Spectroscopic Analysis of Sulfated β-l,3-Xylan and Sulfation Stereochemistry. Biosci. Biotech. Biochem. 1997, 61, 1281-1285. 12. Antal, M . ; Ebringerová, A.; Simkovic, I. New Aspects in Cationization of Lignocellulose Materials. II. Distribution of Functional Groups in Lignin, Hemicellulose, and Cellulose Components. J. Appl. Polym. Sci. 1984, 29, 643-650.

In Hemicelluloses: Science and Technology; Gatenholm, P., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2003.

325

Downloaded by YORK UNIV on November 25, 2012 | http://pubs.acs.org Publication Date: October 7, 2003 | doi: 10.1021/bk-2004-0864.ch020

13. Simkovic, I.; Mlynár, J.; Alföldi, J.; Micko, M . M . New Aspects in Cationization of Lignocellulose Materials. XI. Modification of Bagasse with Quarternary Ammonium Groups. Holzforschung 1990, 44(2), 113-116. 14. Antal, M . ; Ebringerová, A.; Micko, M . M . Kationisierte Hemicellulosen aus Espenholzmehl und ihr Einsatz in der Papierherstellung. Papier 1991, 45, 232-235. 15. Ebringerová, A . ; Hromádková, Z.; Kacuráková, M . ; Natal, M . Quarternized xylan: synthesis and structural characterization. Carbohydr. Polym. 1994, 24, 301-308. 16. Antal, M . ; Ebringerová, A . ; Hromadková, Z. Struktur und papiertechnische Eigenschaften von Aminoxylanen. Papier 1997, 5, 223-226. 17. Ebringerová, A . Hromádková, Z. Zur Substituentenverteilung in kationischen Xylanderivaten. Angew. Makromol. Chem. 1996, 242, 97-104. 18. Matsumura, S.; Yoshikawa, S. Biodegradable Poly(carboxylic acid) Design In: Agricultural and Synthetic Polymers Biodegradability and Utilization Development, American Chemical Society, Cellulose, Paper, and Textile Division: Washington, D C , A C S Symposium series 433, XI, 323, 5, 1990; p 124. 19. Matsumura, S.; Maeda, S.; Yoshikawa, S. Molecular design of biodegradable poly(carboxylic acid) In: Polymeric materials science and engineering, American Chemical Society, Division of Polymeric Materials Science and Engineering, Washington, DC, 62, 1990, p 984. 20. Matsumura, S.; Maeda, S.; Yoshikawa, S. Molecular design of biodegradable functional polymers, 2, Poly(carboxylic acid) containing xylopyranosediyl groups in the backbone. Makromol. Chem. 1990, 191, 1269-1274. 21. Matsumura, S.; Nishioka, M . ; Yoshikawa, S. Enzymatically degradable poly(carboxylic acid) derived from polysaccharide. Makromol. Chem. Rapid Commun. 1991, 12, 89-94. 22. Andersson, R.; Hoffman, J.; Nahar, N.; Scholander, E . An n.m.r. study of oxidation of cellulose and ( l - > 4 ) - β - D - x y l a n with sodium nitrite in orthophosphoric acid. Carbohydr. Res. 1990, 206, 340-346. 23. Painter, T. J. Preparation and periodate oxidation of C-6-oxycellulose: conformational interpretation of hemiacetal stability. Carbohydr. Res. 1977, 55, 95-103. 24. Heinze, Th.; Klemm, D.; Schnabelrauch, M . ; Nehls, I. Properties and following reactions of homogeneously oxidized cellulose In: Cellulosics: Chemical Biochemical and Material Aspects, Eds. Kennedy, J. F., Phillips, G. O., Williams, P. A . , and Horwood, E., New York, 1993, p 340. 25. Jerez, J. R.; Matsuhiro, B.; Urzúa, C.C. Chemical modifications of the xylan from Palmaria decipiens. Carbohydr. Polym. 1997, 32, 155-159. 26. Barroso, N . P.; Costamagna, J.; Matsuhiro, B.; Villagran, M . E l xilano de palmaria decipiens: Modificacion quimica y formacion de un complejo de Cu(II). B o l . Soc. Chil Quim. 1997, 42, 301-306.

In Hemicelluloses: Science and Technology; Gatenholm, P., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2003.