View source for Cellulose

{{Short description|Polymer of glucose and structural component of cell wall of plants and green algae}}
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| Name           = Cellulose
| Reference      = <ref>{{Cite journal |first1 = Yoshiharu |last1 = Nishiyama |first2 = Paul |last2 = Langan |first3 = Henri |last3 = Chanzy |title = Crystal Structure and Hydrogen-Bonding System in Cellulose Iβ from Synchrotron X-ray and Neutron Fiber Diffraction |journal = J. Am. Chem. Soc. |year = 2002 |volume = 124 |issue = 31 |pages = 9074–9082 |doi = 10.1021/ja0257319 |pmid = 12149011 |bibcode = 2002JAChS.124.9074N }}</ref>
| ImageFile      = Cellulose Struktur in Sesselform.svg
| ImageSize      = 260px
| ImageName      = Cellulose, a linear polymer of D-glucose units linked by β(1→4)-glycosidic bonds
| ImageClass     = skin-invert-image
| ImageFile1     = Cellulose-Ibeta-from-xtal-2002-3D-balls.png
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| ImageSize1     = 260px
| ImageName1     = Three-dimensional structure of cellulose
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| Section1       = {{Chembox Identifiers
 | CASNo = 9004-34-6
 | ChEMBL_Ref = {{ebicite|changed|EBI}}
 | ChEMBL = 2109009
 | CASNo_Ref = {{cascite|correct|CAS}}
 | EC_number = 232-674-9
 | UNII_Ref = {{fdacite|correct|FDA}}
 | UNII = SMD1X3XO9M
 | KEGG = C00760
 | PubChem = 14055602
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| Section2       = {{Chembox Properties
 | Formula = ({{chem|C|6|H|10|O|5|)|''n''}}
 | MolarMass = 162.1406 g/mol per glucose unit
 | Appearance = white powder
 | Density = 1.5 g/cm<sup>3</sup>
 | Solubility = none
 | MeltingPtF = 500-518
 | MeltingPt_notes = (decomposes)<ref name="NIOSH"/>
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| Section4       = {{Chembox Thermochemistry
 | DeltaHf = −963 kJ/mol{{clarify|reason=This huge number is surely not per unit. Providing the source would be nice too.|date=June 2021}}
 | DeltaHc = −2828 kJ/mol{{clarify|reason=This huge number is surely not per unit. Providing the source would be nice too.|date=June 2021}}
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| Section7       = {{Chembox Hazards
 | NFPA-H = 1
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 | ExternalSDS =
 | AutoignitionPt =
 | PEL = TWA 15 mg/m<sup>3</sup> (total) TWA 5 mg/m<sup>3</sup> (resp)<ref name="NIOSH">{{PGCH|0110}}</ref>
 | REL = TWA 10 mg/m<sup>3</sup> (total) TWA 5 mg/m<sup>3</sup> (resp)<ref name="NIOSH"/>
 | IDLH = N.D.<ref name="NIOSH"/>
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| Section8       = {{Chembox Related
 | OtherCompounds = [[Starch]]
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}}

'''Cellulose''' is an [[organic compound]] with the [[chemical formula|formula]] {{chem|([[carbon|C]]|6|[[hydrogen|H]]|10|[[oxygen|O]]|5|)|''n''|}}, a [[polysaccharide]] consisting of a linear chain of several hundred to many thousands of [[glycosidic bond|β(1→4) linked]] [[glucose|<small>D</small>-glucose]] units.<ref name="Crawford-1981">{{cite book
 | author=Crawford, R. L.
 | title=Lignin biodegradation and transformation
 | publisher=John Wiley and Sons
 | location=New York
 | year=1981
 | isbn=978-0-471-05743-7
}}</ref><ref name="Updegraff-1969">{{cite journal
 | author=Updegraff D. M.
 | title=Semimicro determination of cellulose in biological materials
 | journal=Analytical Biochemistry
 | year=1969 |volume=32 |pages=420–424
 | doi=10.1016/S0003-2697(69)80009-6
 | pmid=5361396
 | issue=3
}}</ref> Cellulose is an important structural component of the [[cell wall|cell walls]] of [[green plants]], many forms of [[algae]], and the [[oomycete]]s. Some species of [[bacteria]] secrete it to form [[biofilm]]s.<ref>{{cite book |last=Romeo |first=Tony |title=Bacterial biofilms |year=2008 |publisher=Springer |location=Berlin |isbn=978-3-540-75418-3 |pages=258–263}}</ref> Cellulose is the most abundant [[biopolymer|organic polymer]] on Earth.<ref name="Klemm-2005">{{cite journal |last=Klemm |first=Dieter |author2=Heublein, Brigitte |author3=Fink, Hans-Peter |author4= Bohn, Andreas |title=Cellulose: Fascinating Biopolymer and Sustainable Raw Material |journal=Angew. Chem. Int. Ed. |date=2005 |volume=44 |issue=22 |doi=10.1002/anie.200460587 |pmid=15861454 |pages=3358–3393 |bibcode=2005ACIE...44.3358K }}</ref> The cellulose content of [[cotton]] fibre is 90%, that of [[wood]] is 40–50%, and that of dried [[hemp]] is approximately 57%.<ref>Cellulose. (2008). In ''[[Encyclopædia Britannica]]''. Retrieved January 11, 2008, from Encyclopædia Britannica Online.</ref><ref>[http://www.ipst.gatech.edu/faculty/ragauskas_art/technical_reviews/Chemical%20Overview%20of%20Wood.pdf Chemical Composition of Wood]. {{Webarchive|url=https://web.archive.org/web/20181013004234/http://www.ipst.gatech.edu/faculty/ragauskas_art/technical_reviews/Chemical%20Overview%20of%20Wood.pdf |date=October 13, 2018 }}. ipst.gatech.edu.</ref><ref>Piotrowski, Stephan and Carus, Michael (May 2011) [http://www.biocore-europe.org/file/BIOCORE%20Multi-criteria%20evaluation%20of%20niche%20crops.pdf Multi-criteria evaluation of lignocellulosic niche crops for use in biorefinery processes] {{Webarchive|url=https://web.archive.org/web/20210403200802/http://www.biocore-europe.org/file/BIOCORE%20Multi-criteria%20evaluation%20of%20niche%20crops.pdf |date=April 3, 2021 }}. nova-Institut GmbH, Hürth, Germany.</ref>

Cellulose is used mainly to produce [[paperboard]] and [[paper]]. Smaller quantities are converted into a wide variety of derivative products such as [[cellophane]] and [[rayon]]. Conversion of cellulose from [[energy crop]]s into [[biofuel]]s such as [[cellulosic ethanol]] is under development as a [[renewable fuel]] source. Cellulose for industrial use is mainly obtained from [[wood pulp]] and [[cotton]].<ref name="Klemm-2005"/> In addition, cellulose exhibits pronounced susceptibility to direct interactions with certain organic liquids, notably [[formamide]], [[DMSO]], and short-chain amines ([[methylamine]], [[ethylamine]]), among other, are recognized as highly effective swelling agents.<ref>{{cite journal | last1=Mantanis | first1=G. I. | last2=Young | first2=R. A. | last3=Rowell | first3=R. M. | author1-link=George Mantanis | author2-link=Raymond A. Young | author3-link=Roger M. Rowell | title=Swelling of compressed cellulose fiber webs in organic liquids | journal=Cellulose | volume=2 | issue=1 | date=1995 | issn=0969-0239 | doi=10.1007/BF00812768 | pages=1–22}}</ref>

Some animals, particularly [[ruminant]]s and [[termite]]s, can [[digestion|digest]] cellulose with the help of [[symbiosis|symbiotic]] micro-organisms that live in their guts, such as ''[[Trichonympha]]''. In [[human nutrition]], cellulose is a non-digestible constituent of [[insoluble]] [[dietary fiber]], acting as a [[hydrophilic]] [[bulking agent]] for [[human feces|feces]] and potentially aiding in [[defecation]].

== History ==
Cellulose was discovered in 1838 by the French chemist [[Anselme Payen]], who isolated it from plant matter and determined its chemical formula.<ref name="Crawford-1981" /><ref>Payen, A. (1838) "Mémoire sur la composition du tissu propre des plantes et du ligneux" (Memoir on the composition of the tissue of plants and of woody [material]), ''Comptes rendus'', vol. 7, pp. 1052–1056. Payen added appendices to this paper on December 24, 1838 (see: ''Comptes rendus'', vol. 8, p. 169 (1839)) and on February 4, 1839 (see: ''Comptes rendus'', vol. 9, p. 149 (1839)). A committee of the French Academy of Sciences reviewed Payen's findings in : Jean-Baptiste Dumas (1839) "Rapport sur un mémoire de M. Payen, reltes rendus'', vol. 8, pp. 51–53. In this report, the word "cellulose" is coined and author points out the similarity between the empirical formula of cellulose and that of "dextrine" (starch). The above articles are reprinted in: Brongniart and Guillemin, eds., ''Annales des sciences naturelles'' ..., 2nd series, vol. 11 (Paris, France: Crochard et Cie., 1839), [ {{google books|plainurl=y|id=VDRsFWwgUo4C|page=21}}
pp. 21–31].</ref><ref name="Young-1986">{{cite book
| last = Young
| first = Raymond
| title = Cellulose structure modification and hydrolysis
| publisher = Wiley
| location = New York
| year = 1986
| isbn = 978-0-471-82761-0}}</ref> Cellulose was used to produce the first successful [[thermoplastic|thermoplastic polymer]], [[celluloid]], by Hyatt Manufacturing Company in 1870. Production of [[rayon]] ("artificial [[silk]]") from cellulose began in the 1890s and [[cellophane]] was invented in 1912. [[Hermann Staudinger]] determined the polymer structure of cellulose in 1920. The compound was first chemically synthesized (without the use of any biologically derived [[enzyme]]s) in 1992, by Kobayashi and Shoda.<ref>{{cite journal|last=Kobayashi|first=Shiro|author2=Kashiwa, Keita |author3=Shimada, Junji |author4=Kawasaki, Tatsuya |author5= Shoda, Shin-ichiro |title=Enzymatic polymerization: The first in vitro synthesis of cellulose via nonbiosynthetic path catalyzed by cellulase|journal=Makromolekulare Chemie. Macromolecular Symposia|year=1992|volume=54–55|issue=1|pages=509–518|doi=10.1002/masy.19920540138}}</ref>

[[File:Plant cell wall diagram-en.svg|thumb|upright=1.3|The arrangement of cellulose and other [[polysaccharides]] in a plant [[cell wall]]]]

== Structure and properties ==
[[File:Салфетка универсальная губчатая (вид сбоку).jpg|thumb|left|Cellulose under a microscope]]
Cellulose has no taste, is odorless, is [[hydrophilic]] with the [[contact angle]] of 20–30 degrees,<ref>{{cite book|title=Vacuum deposition onto webs, films, and foils|editor=Bishop, Charles A. |year=2007|isbn=978-0-8155-1535-7|url={{google books|plainurl=y|id=vP9E3z7o6iIC|page=165}}|page=165|publisher=Elsevier Science }}</ref> is insoluble in [[water]] and most organic [[solvent]]s, is [[Chirality (chemistry)|chiral]] and is [[biodegradation|biodegradable]]. It was shown to melt at 467&nbsp;°C in pulse tests made by Dauenhauer ''et al.'' (2016).<ref name="Dauenhauer-2016">{{cite journal|last1=Dauenhauer|first1=Paul|last2=Krumm|first2=Christoph|last3=Pfaendtner|first3=Jim|title=Millisecond Pulsed Films Unify the Mechanisms of Cellulose Fragmentation|journal=Chemistry of Materials|volume=28|page=0001|year=2016|doi=10.1021/acs.chemmater.6b00580|issue=1|osti=1865816 }}</ref> It can be broken down chemically into its glucose units by treating it with concentrated mineral acids at high temperature.<ref>{{cite journal|last1=Wymer|first1=Charles E.|title=Ethanol from lignocellulosic biomass: Technology, economics, and opportunities|journal=Bioresource Technology|date=1994|volume= 50|issue=1|page=5|doi=10.1016/0960-8524(94)90214-3|bibcode=1994BiTec..50....3W }}</ref>

Cellulose is derived from [[Glucose|<small>D</small>-glucose]] units, which [[condensation reaction|condense]] through β(1→4)-[[glycosidic bond]]s. This linkage motif contrasts with that for α(1→4)-glycosidic bonds present in [[starch]] and [[glycogen]]. Cellulose is a straight chain polymer. Unlike starch, no coiling or branching occurs and the molecule adopts an extended and rather stiff rod-like conformation, aided by the equatorial conformation of the glucose residues. The multiple [[hydroxyl|hydroxyl groups]] on the glucose from one chain form [[hydrogen bond]]s with oxygen atoms on the same or on a neighbour chain, holding the chains firmly together side-by-side and forming ''microfibrils'' with high [[tensile strength]]. This confers tensile strength in [[cell wall]]s where cellulose microfibrils are meshed into a polysaccharide ''matrix''. The high tensile strength of plant stems and of the tree wood also arises from the arrangement of cellulose fibers intimately distributed into the [[lignin]] matrix. The mechanical role of cellulose fibers in the wood matrix responsible for its strong structural resistance, can somewhat be compared to that of the [[reinforcement bar]]s in [[concrete]], [[lignin]] playing here the role of the [[cement|hardened cement paste]] acting as the "glue" in between the cellulose fibres. Mechanical properties of cellulose in primary plant cell wall are correlated with growth and expansion of plant cells.<ref name="Bidhendi-2016">{{cite journal|last1=Bidhendi|first1=Amir J|last2=Geitmann|first2=Anja|title=Relating the mechanical properties of the primary plant cell wall. |url=https://academic.oup.com/jxb/article-pdf/67/2/449/9366354/erv535.pdf |archive-url=https://web.archive.org/web/20180113093611/https://academic.oup.com/jxb/article-pdf/67/2/449/9366354/erv535.pdf |archive-date=January 13, 2018 |url-status=live|journal=Journal of Experimental Botany|date=January 2016|volume=67|issue=2|pages=449–461|doi=10.1093/jxb/erv535|pmid=26689854|doi-access=free}}</ref> Live fluorescence microscopy techniques are promising in investigation of the role of cellulose in growing plant cells.<ref name="Bidhendi-2020">{{cite journal|last1=Bidhendi|first1=AJ|last2=Chebli|first2=Y|last3=Geitmann|first3=A|title= Fluorescence Visualization of Cellulose and Pectin in the Primary Plant Cell Wall|journal=Journal of Microscopy|volume=278 |issue=3 |pages=164–181|date=May 2020|doi=10.1111/jmi.12895|pmid=32270489|s2cid=215619998}}</ref>

[[File:Cellulose spacefilling model.jpg|thumb|A triple strand of cellulose showing the [[hydrogen bond]]s (cyan lines) between glucose strands]]
[[File:Cotton.JPG|thumb|[[Cotton]] fibres represent the purest natural form of cellulose, containing more than 90% of this [[polysaccharide]].]]
Compared to starch, cellulose is also much more [[crystallinity|crystalline]]. Whereas starch undergoes a crystalline to [[amorphous solid|amorphous]] transition when heated beyond 60–70&nbsp;°C in water (as in cooking), cellulose requires a temperature of 320&nbsp;°C and pressure of 25 [[Pascal (unit)|MPa]] to become amorphous in water.<ref name="Deguchi-2006">{{cite journal|last1=Deguchi|first1=Shigeru|last2=Tsujii|first2=Kaoru|last3=Horikoshi|first3=Koki|title=Cooking cellulose in hot and compressed water|journal=Chemical Communications|year=2006|doi=10.1039/b605812d|pmid=16883414|issue=31|pages=3293–5}}</ref>

Several types of cellulose are known. These forms are distinguished according to the location of hydrogen bonds between and within strands. Natural cellulose is cellulose I, with structures I<sub>α</sub> and I<sub>β</sub>. Cellulose produced by bacteria and algae is enriched in I<sub>α</sub> while cellulose of higher plants consists mainly of I<sub>β</sub>. Cellulose in [[regenerated cellulose]] fibers is cellulose II. The conversion of cellulose I to cellulose II is irreversible, suggesting that cellulose I is [[Metastability|metastable]] and cellulose II is stable. With various chemical treatments it is possible to produce the structures cellulose III and cellulose IV.<ref>[http://www.cermav.cnrs.fr/glyco3d/lessons/cellulose/index.html Structure and morphology of cellulose] {{webarchive |url=https://web.archive.org/web/20090426122947/http://www.cermav.cnrs.fr/glyco3d/lessons/cellulose/index.html |date=April 26, 2009 }} by Serge Pérez and William Mackie, CERMAV-[[CNRS]], 2001. Chapter IV.</ref>

Many properties of cellulose depend on its chain length or [[degree of polymerization]], the number of glucose units that make up one polymer molecule. Cellulose from wood pulp has typical chain lengths between 300 and 1700 units; cotton and other plant fibers as well as bacterial cellulose have chain lengths ranging from 800 to 10,000 units.<ref name="Klemm-2005"/> Molecules with very small chain length resulting from the breakdown of cellulose are known as [[cellodextrin]]s; in contrast to long-chain cellulose, cellodextrins are typically soluble in water and organic solvents.

The chemical formula of cellulose is (C<sub>6</sub>H<sub>10</sub>O<sub>5</sub>)<sub>n</sub> where n is the degree of polymerization and represents the number of glucose groups.<ref>{{cite book |last1=Chen |first1=Hongzhang |title= Biotechnology of Lignocellulose: Theory and Practice |date=2014 |publisher=Springer |location=Dordrecht |isbn=978-94-007-6897-0 |pages=25–71 |chapter=Chemical Composition and Structure of Natural Lignocellulose|url= https://www.springer.com/cda/content/document/cda_downloaddocument/9789400768970-c2.pdf |archive-url=https://web.archive.org/web/20161213103751/http://www.springer.com/cda/content/document/cda_downloaddocument/9789400768970-c2.pdf |archive-date=December 13, 2016 |url-status=live}}</ref>

Plant-derived cellulose is usually found in a mixture with [[hemicellulose]], [[lignin]], [[pectin]], and other substances, while [[bacterial cellulose]] is quite pure, has a much higher water content and higher tensile strength due to higher chain lengths.<ref name="Klemm-2005"/>{{rp|3384}}

Cellulose consists of fibrils with [[crystalline]] and [[amorphous solid|amorphous]] regions.<ref>{{cite web | last=Mantanis | first=George I | title=PhD Thesis: Swelling of lignocellulosic materials in water and organic liquids; George Mantanis (Univ. of Wisconsin-Madison, 1994) | website=Academia.edu | date=2011-02-01 | url=https://www.academia.edu/42773 | access-date=2024-11-21}}</ref> These cellulose fibrils may be individualized by mechanical treatment of cellulose pulp, often assisted by chemical [[oxidation]] or [[enzyme|enzymatic]] treatment, yielding semi-flexible [[nanocellulose|cellulose nanofibrils]] generally 200&nbsp;nm to 1 μm in length depending on the treatment intensity.<ref>{{cite journal |last1=Saito |first1=Tsuguyuki |last2=Kimura |first2=Satoshi |last3=Nishiyama |first3=Yoshiharu |last4=Isogai |first4=Akira |title=Cellulose Nanofibers Prepared by TEMPO-Mediated Oxidation of Native Cellulose |journal=Biomacromolecules |date=August 2007 |volume=8 |issue=8 |pages=2485–2491 |doi=10.1021/bm0703970 |pmid=17630692 |url=https://pubs.acs.org/doi/abs/10.1021/bm0497769 |access-date=April 7, 2020 |archive-date=April 7, 2020 |archive-url=https://web.archive.org/web/20200407120236/https://pubs.acs.org/doi/abs/10.1021/bm0497769 |url-status=live |url-access=subscription }}</ref> Cellulose pulp may also be treated with strong acid to [[hydrolization|hydrolyze]] the amorphous fibril regions, thereby producing short rigid [[nanocellulose|cellulose nanocrystals]] a few 100&nbsp;nm in length.<ref>{{cite journal|year=2011|title=Chemistry and applications of nanocrystalline cellulose and its derivatives: A nanotechnology perspective|journal=The Canadian Journal of Chemical Engineering|volume=89|issue=5|pages=1191–1206|url=http://www.arboranano.ca/pdfs/Chemistry%20and%20applications%20of%20nanocrystalline%20cellulose%20and%20its%20derivatives%20A%20nanotechnology%20perspective-2011.pdf|author1=Peng, B. L.|author2=Dhar, N.|author3=Liu, H. L.|author4=Tam, K. C.|doi=10.1002/cjce.20554|bibcode=2011CJChE..89.1191P |access-date=August 28, 2012|archive-url=https://web.archive.org/web/20161024021059/http://www.arboranano.ca/pdfs/Chemistry%20and%20applications%20of%20nanocrystalline%20cellulose%20and%20its%20derivatives%20A%20nanotechnology%20perspective-2011.pdf|archive-date=October 24, 2016|url-status=dead}}</ref> These [[nanocellulose]]s are of high technological interest due to their [[self-assembly]] into [[liquid crystal|cholesteric liquid crystals]],<ref>{{cite journal |last1=Revol |first1=J.-F. |last2=Bradford |first2=H. |last3=Giasson |first3=J. |last4=Marchessault |first4=R.H. |last5=Gray |first5=D.G. |title=Helicoidal self-ordering of cellulose microfibrils in aqueous suspension |journal=International Journal of Biological Macromolecules |date=June 1992 |volume=14 |issue=3 |pages=170–172 |doi=10.1016/S0141-8130(05)80008-X |pmid=1390450 |url=https://www.sciencedirect.com/science/article/pii/S014181300580008X |access-date=April 7, 2020 |archive-date=April 7, 2020 |archive-url=https://web.archive.org/web/20200407120239/https://www.sciencedirect.com/science/article/pii/S014181300580008X |url-status=live |url-access=subscription }}</ref> production of [[hydrogel]]s or [[aerogel]]s,<ref>{{cite journal |last1=De France |first1=Kevin J. |last2=Hoare |first2=Todd |last3=Cranston |first3=Emily D. |author-link3=Emily Cranston |date=April 26, 2017 |title=Review of Hydrogels and Aerogels Containing Nanocellulose |journal=Chemistry of Materials |volume=29 |issue=11 |pages=4609–4631 |doi=10.1021/acs.chemmater.7b00531 |doi-access=free}}</ref> use in [[nanocomposite]]s with superior thermal and mechanical properties,<ref>{{Cite journal | last1 = Pranger | first1 = L. | last2 = Tannenbaum | first2 = R. | doi = 10.1021/ma8020213 | title = Biobased Nanocomposites Prepared by in Situ Polymerization of Furfuryl Alcohol with Cellulose Whiskers or Montmorillonite Clay | journal = Macromolecules | volume = 41 | issue = 22 | pages = 8682–8687 | year = 2008 | bibcode = 2008MaMol..41.8682P | url = https://figshare.com/articles/journal_contribution/2897695 | access-date = June 19, 2023 | archive-date = December 30, 2023 | archive-url = https://web.archive.org/web/20231230132201/https://figshare.com/articles/journal_contribution/Biobased_Nanocomposites_Prepared_by_In_Situ_Polymerization_of_Furfuryl_Alcohol_with_Cellulose_Whiskers_or_Montmorillonite_Clay/2897695 | url-status = live | url-access = subscription }}</ref> and use as [[Pickering emulsion|Pickering]] stabilizers for [[emulsions]].<ref>{{cite journal |last1=Kalashnikova |first1=Irina |last2=Bizot |first2=Hervé |last3=Cathala |first3=Bernard |last4=Capron |first4=Isabelle |title=New Pickering Emulsions Stabilized by Bacterial Cellulose Nanocrystals |journal=Langmuir |date=June 21, 2011 |volume=27 |issue=12 |pages=7471–7479 |doi=10.1021/la200971f |pmid=21604688 }}</ref>

==Processing==

=== Biosynthesis ===

In [[Viridiplantae|plant]]s cellulose is synthesized at the [[plasma membrane]] by rosette terminal complexes (RTCs). The RTCs are [[oligomer|hexameric]] protein structures, approximately 25 [[nanometre|nm]] in diameter, that contain the [[cellulose synthase (UDP-forming)|cellulose synthase]] enzymes that synthesise the individual cellulose chains.<ref>{{cite journal|doi=10.2307/3871010|last1=Kimura|first1=S|last2=Laosinchai|first2=W|last3=Itoh|first3=T|last4=Cui|first4=X|last5=Linder|first5=CR|last6=Brown Jr|first6=RM|title=Immunogold labeling of rosette terminal cellulose-synthesizing complexes in the vascular plant vigna angularis|journal=The Plant Cell|volume=11|issue=11|pages=2075–86|year=1999|pmid=10559435|pmc=144118|jstor=3871010}}</ref> Each RTC floats in the cell's plasma membrane and "spins" a microfibril into the [[cell wall]].{{citation needed|date=January 2025}}

RTCs contain at least three different [[cellulose synthase]]s, encoded by ''CesA'' (''Ces'' is short for "cellulose synthase") genes, in an unknown [[stoichiometry]].<ref>{{cite journal|last1=Taylor|first1=N. G.|title=Interactions among three distinct CesA proteins essential for cellulose synthesis|journal=Proceedings of the National Academy of Sciences|volume=100|pages=1450–1455|year=2003|doi=10.1073/pnas.0337628100|issue=3|pmid=12538856|pmc=298793|bibcode=2003PNAS..100.1450T|doi-access=free}}</ref> Separate sets of ''CesA'' genes are involved in primary and secondary cell wall biosynthesis. There are known to be about seven subfamilies in the plant ''CesA'' superfamily, some of which include the more cryptic, tentatively-named ''Csl'' (cellulose synthase-like) enzymes. These cellulose syntheses use UDP-glucose to form the β(1→4)-linked cellulose.<ref name="Richmond-2000">{{cite journal|last1=Richmond|first1=Todd A|last2=Somerville|first2=Chris R|title=The Cellulose Synthase Superfamily|journal=Plant Physiology|date=October 2000|volume=124|issue=2|pages=495–498|doi=10.1104/pp.124.2.495|pmid=11027699|pmc=1539280}}</ref>

[[Bacterial cellulose]] is produced using the same family of proteins, although the gene is called ''BcsA'' for "bacterial cellulose synthase" or ''CelA'' for "cellulose" in many instances.<ref name="Omadjela-2013"/> In fact, plants acquired ''CesA'' from the endosymbiosis event that produced the [[chloroplast]].<ref name="Popper-2011">{{cite journal | vauthors = Popper ZA, Michel G, Hervé C, Domozych DS, Willats WG, Tuohy MG, Kloareg B, Stengel DB | s2cid = 11961888 | title = Evolution and diversity of plant cell walls: from algae to flowering plants | journal = Annual Review of Plant Biology | volume = 62 | pages = 567–90 | date = 2011 | issue = 1 | pmid = 21351878 | doi = 10.1146/annurev-arplant-042110-103809 | bibcode = 2011AnRPB..62..567P | hdl = 10379/6762 | hdl-access = free }}</ref> All cellulose synthases known belongs to [[glycosyltransferase]] family 2 (GT2).<ref name="Omadjela-2013">{{cite journal |last1=Omadjela |first1=O |last2=Narahari |first2=A |last3=Strumillo |first3=J |last4=Mélida |first4=H |last5=Mazur |first5=O |last6=Bulone |first6=V |last7=Zimmer |first7=J |title=BcsA and BcsB form the catalytically active core of bacterial cellulose synthase sufficient for in vitro cellulose synthesis. |journal=Proceedings of the National Academy of Sciences of the United States of America |date=October 29, 2013 |volume=110 |issue=44 |pages=17856–61 |doi=10.1073/pnas.1314063110 |pmid=24127606 |pmc=3816479 |doi-access=free|bibcode=2013PNAS..11017856O }}</ref>

Cellulose synthesis requires chain initiation and elongation, and the two processes are separate.
Cellulose synthase (''CesA'') initiates cellulose polymerization using a [[steroid]] primer, [[beta-sitosterol|sitosterol]]-beta-[[glucoside]], and UDP-glucose. It then utilises [[Uridine diphosphate|UDP]]-D-glucose precursors to elongate the growing cellulose chain. A [[cellulase]] may function to cleave the primer from the mature chain.<ref>{{cite journal|last1=Peng|first1=L|last2=Kawagoe|first2=Y|last3=Hogan|first3=P|last4=Delmer|first4=D|title=Sitosterol-beta-glucoside as primer for cellulose synthesis in plants|journal=Science|volume=295|issue=5552|pages=147–50|year=2002|pmid=11778054|doi=10.1126/science.1064281|bibcode=2002Sci...295..147P|s2cid=83564483}}</ref>

Cellulose is also synthesised by [[tunicate]] animals, particularly in the [[test (biology)|test]]s of [[ascidian]]s (where the cellulose was historically termed "tunicine" (tunicin)).<ref>{{cite journal|author=Endean, R|url=http://jcs.biologists.org/content/s3-102/57/107.full.pdf |archive-url=https://web.archive.org/web/20141026222752/http://jcs.biologists.org/content/s3-102/57/107.full.pdf |archive-date=October 26, 2014 |url-status=live |title=The Test of the Ascidian, ''Phallusia mammillata''|journal= Quarterly Journal of Microscopical Science|volume=102|issue=1|pages=107–117|year= 1961}}</ref>

=== Breakdown (cellulolysis) ===

Cellulolysis is the process of breaking down cellulose into smaller polysaccharides called [[cellodextrin]]s or completely into [[glucose]] units; this is a [[hydrolysis]] reaction. Because cellulose molecules bind strongly to each other, cellulolysis is relatively difficult compared to the breakdown of other [[polysaccharide]]s.<ref>{{cite journal|year=2014|doi=10.1036/1097-8542.118200|author1=Barkalow, David G.  |author2=Whistler, Roy L.|title=Cellulose|journal=AccessScience}}</ref> However, this process can be significantly intensified in a proper [[solvent]], e.g. in an [[ionic liquid]].<ref name="Ignatyev-2011">{{cite journal|last=Ignatyev|first=Igor|author2=Doorslaer, Charlie Van|author3=Mertens, Pascal G.N.|author4=Binnemans, Koen|author5=Vos, Dirk. E. de|s2cid=101737591|journal=Holzforschung|year=2011|volume=66|issue=4|pages=417–425|title=Synthesis of glucose esters from cellulose in ionic liquids|doi=10.1515/hf.2011.161|url=https://lirias.kuleuven.be/handle/123456789/321763|access-date=August 30, 2017|archive-date=August 30, 2017|archive-url=https://web.archive.org/web/20170830193820/https://lirias.kuleuven.be/handle/123456789/321763|url-status=live|url-access=subscription}}</ref>

Most mammals have limited ability to digest dietary fibre such as cellulose. Some [[ruminant]]s like cows and sheep contain certain [[symbiosis|symbiotic]] [[Anaerobic organism|anaerobic]] bacteria (such as ''[[Cellulomonas]]'' and ''[[Ruminococcus]]'' [[species|spp.]]) in the flora of the [[rumen]], and these bacteria produce [[enzyme]]s called [[cellulase]]s that hydrolyze cellulose. The breakdown products are then used by the bacteria for proliferation.<ref name="La Reau-2018">{{Cite journal|title = The Ruminococci: key symbionts of the gut ecosystem|journal = Journal of Microbiology|date = 2018|pages = 199–208| volume = 56 | issue = 3 |pmid =29492877|doi =10.1007/s12275-018-8024-4|first1 = A.J.|last1 = La Reau|first2 = G.|last2 = Suen|s2cid = 3578123}}</ref> The bacterial mass is later digested by the ruminant in its [[digestive system]] ([[stomach]] and [[small intestine]]). [[Horse]]s use cellulose in their diet by [[hindgut fermentation|fermentation in their hindgut]].<ref>{{cite web |last1=Bowen |first1=Richard |title=Digestive Function of Horses |url=http://www.vivo.colostate.edu/hbooks/pathphys/digestion/herbivores/horses.html |website=www.vivo.colostate.edu |access-date=September 25, 2020 |archive-date=November 12, 2020 |archive-url=https://web.archive.org/web/20201112015454/http://www.vivo.colostate.edu/hbooks/pathphys/digestion/herbivores/horses.html |url-status=live }}</ref> Some [[termite]]s contain in their [[hindgut]]s certain [[flagellate]] [[protozoa]] producing such enzymes, whereas others contain bacteria or may produce cellulase.<ref>{{Cite journal|title=Hidden cellulases in termites: revision of an old hypothesis|journal=Biology Letters|volume=3|pages=336–339|doi=10.1098/rsbl.2007.0073|date=June 22, 2007|author8=Tokuda, Gaku and Hirofumi Watanabe|issue=3|pmid=17374589|last1=Tokuda|first1=G|last2=Watanabe|first2=H|pmc=2464699}}</ref>

The enzymes used to [[wikt:cleave|cleave]] the [[glycosidic linkage]] in cellulose are [[glycoside hydrolase]]s including endo-acting [[cellulase]]s and exo-acting [[glucosidase]]s. Such enzymes are usually secreted as part of multienzyme complexes that may include [[dockerin]]s and [[carbohydrate-binding module]]s.<ref>{{Cite journal|doi=10.1021/cr500351c|title=Fungal Cellulases|year=2015|last1=Payne|first1=Christina M.|last2=Knott|first2=Brandon C.|last3=Mayes|first3=Heather B.|last4=Hansson|first4=Henrik|last5=Himmel|first5=Michael E.|last6=Sandgren|first6=Mats|last7=Ståhlberg|first7=Jerry|last8=Beckham|first8=Gregg T.|journal=Chemical Reviews|volume=115|issue=3|pages=1308–1448|pmid=25629559|doi-access=free}}</ref>

=== Breakdown (thermolysis) ===
{{See also|Wood ash#Composition}}
At temperatures above 350&nbsp;°C, cellulose undergoes [[thermolysis]] (also called '[[pyrolysis]]'), decomposing into solid [[Char (chemistry)|char]], vapors, [[aerosols]], and gases such as [[carbon dioxide]].<ref>{{cite journal|author1=Mettler, Matthew S. |author2=Vlachos, Dionisios G. |author3=Dauenhauer, Paul J. |title=Top Ten Fundamental Challenges of Biomass Pyrolysis for Biofuels|journal=Energy & Environmental Science |volume=5 |issue=7 |pages=7797 |doi=10.1039/C2EE21679E |year=2012 |bibcode=2012EnEnS...5.7797M }}</ref> Maximum yield of vapors which condense to a liquid called ''[[bio-oil]]'' is obtained at 500&nbsp;°C.<ref>{{Cite journal|title=Overview of Applications of Biomass Fast Pyrolysis Oil|journal=Energy & Fuels |volume=18 |issue=2 |pages=590–598 |publisher= Energy & Fuels, American Chemical Society|doi=10.1021/ef034067u |year=2004 |last1 = Czernik|first1 = S.|last2=Bridgwater |first2=A. V. |bibcode=2004EnFue..18..590C |s2cid=49332510 }}</ref>

Semi-crystalline cellulose polymers react at pyrolysis temperatures (350–600&nbsp;°C) in a few seconds; this transformation has been shown to occur via a solid-to-liquid-to-vapor transition, with the liquid (called ''intermediate liquid cellulose'' or ''molten cellulose'') existing for only a fraction of a second.<ref>{{cite journal|doi=10.1039/B915068B  |title=Reactive Boiling of Cellulose for Integrated Catalysis through an Intermediate Liquid|journal=Green Chemistry|volume=11|issue=10|pages=1555|year=2009|last1=Dauenhauer|first1=Paul J.|last2=Colby|first2=Joshua L.|last3=Balonek|first3=Christine M.|last4=Suszynski|first4=Wieslaw J.|last5=Schmidt|first5=Lanny D.|s2cid=96567659}}</ref> Glycosidic bond cleavage produces short cellulose chains of two-to-seven [[monomers]] comprising the melt. Vapor bubbling of intermediate liquid cellulose produces [[aerosols]], which consist of short chain anhydro-oligomers derived from the melt.<ref>{{cite journal|title= Aerosol Generation by Reactive Boiling Ejection of Molten Cellulose|journal= Energy & Environmental Science|volume= 4|issue= 10|pages= 4306|publisher= Energy & Environmental Science, Royal Society of Chemistry|doi= 10.1039/C1EE01876K|year= 2011|last1= Teixeira|first1= Andrew R.|last2= Mooney|first2= Kyle G.|last3= Kruger|first3= Jacob S.|last4= Williams|first4= C. Luke|last5= Suszynski|first5= Wieslaw J.|last6= Schmidt|first6= Lanny D.|last7= Schmidt|first7= David P.|last8= Dauenhauer|first8= Paul J.|bibcode= 2011EnEnS...4.4306T|url= http://works.bepress.com/paul_dauenhauer/5|access-date= August 30, 2017|archive-date= August 31, 2017|archive-url= https://web.archive.org/web/20170831130431/https://works.bepress.com/paul_dauenhauer/5/|url-status= live}}</ref>

Continuing decomposition of molten cellulose produces volatile compounds including [[levoglucosan]], [[furan]]s, [[pyran]]s, light oxygenates, and gases via primary reactions.<ref>{{cite journal |title=Revealing pyrolysis chemistry for biofuels production: Conversion of cellulose to furans and small oxygenates |journal=Energy Environ. Sci. |volume=5 |pages=5414–5424 |doi=10.1039/C1EE02743C |year=2012 |last1=Mettler |first1=Matthew S. |last2=Mushrif |first2=Samir H. |last3=Paulsen |first3=Alex D. |last4=Javadekar |first4=Ashay D. |last5=Vlachos |first5=Dionisios G. |last6=Dauenhauer |first6=Paul J. |issue=1 |bibcode=2012EnEnS...5.5414M |url=http://works.bepress.com/paul_dauenhauer/6 |access-date=August 30, 2017 |archive-date=August 31, 2017 |archive-url=https://web.archive.org/web/20170831083457/https://works.bepress.com/paul_dauenhauer/6/ |url-status=live }}</ref> Within thick cellulose samples, volatile compounds such as [[levoglucosan]] undergo 'secondary reactions' to volatile products including pyrans and light oxygenates such as [[glycolaldehyde]].<ref>{{cite journal |title=Pyrolytic Conversion of Cellulose to Fuels: Levoglucosan Deoxygenation via Elimination and Cyclization within Molten Biomass|journal=Energy & Environmental Science |volume=5 |issue=7 |pages=7864 |doi=10.1039/C2EE21305B |year=2012 |last1=Mettler |first1=Matthew S. |last2=Paulsen |first2=Alex D. |last3=Vlachos |first3=Dionisios G. |last4=Dauenhauer |first4=Paul J. |bibcode=2012EnEnS...5.7864M }}</ref>

== Hemicellulose ==
{{Main|Hemicellulose}}
[[Hemicellulose]]s are [[polysaccharide]]s related to cellulose that comprises about 20% of the biomass of [[embryophyte|land plants]]. In contrast to cellulose, hemicelluloses (which include [[xylan|xylans]], [[xyloglucan|xyloglucans]], [[mannans|(gluco)mannans]], and [[mixed-linkage glucan|mixed-linkage glucans]]) are derived from several sugars in addition to [[glucose]], especially [[xylose]] but also including [[mannose]], [[galactose]], [[glucuronic acid]], [[fucose]], and [[arabinose]]. Hemicelluloses consist of shorter chains&nbsp;– between 500 and 3000 sugar units.<ref name="Gibson-2013">{{cite journal | author=Gibson LJ | title=The hierarchical structure and mechanics of plant materials | journal= [[Journal of the Royal Society Interface]] | volume=9 | issue=76 | year=2013 | pages=2749–2766 | pmc=3479918 | pmid=22874093 | doi=10.1098/rsif.2012.0341}}</ref> Furthermore, hemicelluloses are often branched, whereas cellulose is unbranched.<ref>{{cite journal |last1=Yoshihisa |first1=Yoshimi |title=Structure, Modification Pattern, and Conformation of Hemicellulose in Plant Biomass |journal=Journal of Applied Glycoscience |date=2024 |volume=72 |issue=1 |article-number=7201301 |doi=10.5458/jag.7201301 |pmid=40200932 |url=https://www.jstage.jst.go.jp/article/jag/72/1/72_7201301/_article |access-date=5 May 2025|pmc=11975222 }}</ref>

==Regenerated cellulose==

Cellulose is soluble in several kinds of media, several of which are the basis of commercial technologies. These dissolution processes are reversible and are used in the production of '''regenerated celluloses''' (such as [[viscose]] and [[cellophane]]) from [[dissolving pulp]].<ref>{{Cite journal |last=Kumar |first=Amit |date=2021-05-01 |title=Dissolving pulp production: Cellulases and xylanases for the enhancement of cellulose accessibility and reactivity |url=https://www.degruyterbrill.com/document/doi/10.1515/psr-2019-0047/html?lang=en#:~:text=Dissolving%20pulps%20are%20the%20basic%20source%20for,by%20pre-hydrolysis%20kraft%20and%20acid%20sulphite%20pulping. |journal=Physical Sciences Reviews |language=en |volume=6 |issue=5 |pages=111–129 |doi=10.1515/psr-2019-0047 |bibcode=2021PhSRv...6...47K |issn=2365-659X|url-access=subscription }}</ref>

The most important solubilizing agent is [[carbon disulfide]] in the presence of alkali. Other agents include [[Schweizer's reagent]], [[N-Methylmorpholine N-oxide|''N''-methylmorpholine ''N''-oxide]], and [[lithium chloride]] in [[dimethylacetamide]]. In general, these agents modify the cellulose, rendering it soluble. The agents are then removed concomitant with the formation of fibers.<ref>{{cite book |last1= Stenius |first1= Per |title= Forest Products Chemistry |series= Papermaking Science and Technology |volume=3 |year= 2000 |publisher= Fapet OY |location= Finland |isbn= 978-952-5216-03-5 |page= 35 |chapter=Ch. 1}}</ref> Cellulose is also soluble in many kinds of [[ionic liquids]].<ref>{{cite journal|title= Ionic liquid processing of cellulose|journal=Chemical Society Reviews |volume=41 |issue=4 |pages=1519–37 |doi=10.1039/C2CS15311D |pmid=22266483 |year=2012 |last1=Wang |first1=Hui |last2=Gurau |first2=Gabriela |last3=Rogers |first3=Robin D. }}</ref>

The history of regenerated cellulose is often cited as beginning with George Audemars, who first manufactured regenerated [[nitrocellulose]] fibers in 1855.<ref name="Abetz-2005">{{cite book|last1=Abetz|first1=Volker|title=Encyclopedia of polymer science and technology|date=2005|publisher=Wiley-Interscience|location=[Hoboken, N.J.]|isbn=978-0-471-44026-0|edition=Wird aktualisiert.}}</ref> Although these fibers were soft and strong -resembling silk- they had the drawback of being highly flammable. [[Hilaire de Chardonnet]] perfected production of nitrocellulose fibers, but manufacturing of these fibers by his process was relatively uneconomical.<ref name="Abetz-2005" /> In 1890, L.H. Despeissis invented the [[Cuprammonium rayon|cuprammonium process]] – which uses a cuprammonium solution to solubilize cellulose – a method still used today for production of [[artificial silk]].<ref>{{cite book|last1=Woodings|first1=Calvin|title=Regenerated cellulose fibres|date=2001|publisher=The Textile Institute|location=[Manchester]|isbn=978-1-85573-459-3}}</ref> In 1891, it was discovered that treatment of cellulose with alkali and carbon disulfide generated a soluble cellulose derivative known as [[viscose]].<ref name="Abetz-2005" /> This process, patented by the founders of the Viscose Development Company, is the most widely used method for manufacturing regenerated cellulose products. [[Courtaulds]] purchased the patents for this process in 1904, leading to significant growth of viscose fiber production.<ref name="Borbély-2008">{{cite journal|last1=Borbély|first1=Éva|title=Lyocell, the New Generation of Regenerated Cellulose|journal=Acta Polytechnica Hungarica|date=2008|volume=5|issue=3}}</ref> By 1931, expiration of patents for the viscose process led to its adoption worldwide. Global production of regenerated cellulose fiber peaked in 1973 at 3,856,000 tons.<ref name="Abetz-2005" />

Regenerated cellulose can be used to manufacture a wide variety of products. While the first application of regenerated cellulose was as a clothing [[textile]], this class of materials is also used in the production of disposable medical devices as well as fabrication of [[Synthetic membrane|artificial membranes]].<ref name="Borbély-2008" />

==Cellulose esters and ethers==
The [[hydroxyl]] groups (−OH) of cellulose can be partially or fully reacted with various [[reagent]]s to afford derivatives with useful properties like mainly cellulose [[ester]]s and cellulose [[ether]]s (−OR). In principle, although not always in current industrial practice, cellulosic polymers are renewable resources.

Ester derivatives include:

{| class="wikitable"
|-
! Cellulose ester !! Reagent !! Example !! Reagent !! Group R
|-
| rowspan=5 | Organic esters
| rowspan=5 | Organic acids
| [[Cellulose acetate]] || [[Acetic acid]] and [[acetic anhydride]] || H or −(C=O)CH<sub>3</sub>
|-
| [[Cellulose triacetate]] || Acetic acid and acetic anhydride || −(C=O)CH<sub>3</sub>
|-
| Cellulose propionate || [[Propionic acid]] || H or −(C=O)CH<sub>2</sub>CH<sub>3</sub>
|-
| Cellulose acetate propionate (CAP)|| Acetic acid and propanoic acid || H or −(C=O)CH<sub>3</sub> or −(C=O)CH<sub>2</sub>CH<sub>3</sub>
|-
| Cellulose acetate butyrate (CAB)|| Acetic acid and [[butyric acid]] || H or −(C=O)CH<sub>3</sub> or −(C=O)CH<sub>2</sub>CH<sub>2</sub>CH<sub>3</sub>
|-
| rowspan=2 | Inorganic esters
| rowspan=2 | Inorganic acids
| [[Nitrocellulose]] (cellulose nitrate) || [[Nitric acid]] or another powerful nitrating agent || H or −NO<sub>2</sub>
|-
| [[Cellulose sulfate]] || [[Sulfuric acid]] or another powerful sulfating agent || H or −SO<sub>3</sub>H
|}

Cellulose acetate and cellulose triacetate are film- and fiber-forming materials that find a variety of uses. Nitrocellulose was initially used as an explosive and was an early film forming material. When plasticized with [[camphor]], nitrocellulose gives [[celluloid]].

Cellulose Ether<ref>{{Cite web|title=Cellulose Ether|url=https://methylcellulose.net/cellulose-ether/|access-date=March 7, 2023|website=methylcellulose.net|date=March 5, 2023|archive-date=March 7, 2023|archive-url=https://web.archive.org/web/20230307132638/https://methylcellulose.net/cellulose-ether/|url-status=live}}</ref> derivatives include:

{| class="wikitable"
|-
! Cellulose ethers !! Reagent !! Example !! Reagent !! Group R = H or !! Water solubility !! Application !! [[E number]]
|-
| rowspan=3 | Alkyl
| rowspan=3 | [[Halogenoalkane]]s
| [[Methylcellulose]] || [[Chloromethane]] || −CH<sub>3</sub> || Cold/Hot water-soluble<ref>{{Cite web|title=Methyl Cellulose|url=https://www.kimacellulose.com/products/methyl-cellulose-mc-cas-9004-67-5/|access-date=April 15, 2023|website=kimacellulose.com|archive-date=April 15, 2023|archive-url=https://web.archive.org/web/20230415010711/https://www.kimacellulose.com/products/methyl-cellulose-mc-cas-9004-67-5/|url-status=live}}</ref> ||  || E461
|-
| [[Ethylcellulose]] (EC) || [[Chloroethane]] || −CH<sub>2</sub>CH<sub>3</sub> || Water-insoluble || A commercial thermoplastic used in coatings, inks, binders, and controlled-release drug tablets,<ref name="Maita-2023">{{cite journal |last1=Maita |first1=Palmieri |title=Toward Sustainable Electronics: Exploiting the Potential of a Biodegradable Cellulose Blend for Photolithographic Processes and Eco-Friendly Devices |journal=Advanced Materials Technologies |date=2023 |volume=1 |issue=9 |article-number=2301282 |doi=10.1002/admt.202301282|hdl=2108/345525 |hdl-access=free }}</ref> also employed in the production of oleogels and bioplastics<ref>{{Cite journal |last1=Lamanna |first1=Leonardo |last2=Corigliano |first2=Gabriele |last3=Narayanan |first3=Athira |last4=Villani |first4=Stefania |last5=Friuli |first5=Marco |last6=Chietera |first6=Francesco P. |last7=Stanca |first7=Benedetta Di Chiara |last8=Giannotti |first8=Laura |last9=Siculella |first9=Luisa |last10=Colella |first10=Riccardo |last11=Catarinucci |first11=Luca |last12=Athanassiou |first12=Athanassia |last13=Cataldi |first13=Pietro |last14=Demitri |first14=Christian |last15=Caironi |first15=Mario |date=2024-10-15 |title=Beyond Plastic: Oleogel as gel-state biodegradable thermoplastics |journal=Chemical Engineering Journal |volume=498 |article-number=154988 |doi=10.1016/j.cej.2024.154988 |bibcode=2024ChEnJ.49854988L |issn=1385-8947|doi-access=free |hdl=10281/512761 |hdl-access=free }}</ref>|| E462
|-
| Ethyl methyl cellulose || Chloromethane and chloroethane || −CH<sub>3</sub> or −CH<sub>2</sub>CH<sub>3</sub> ||  ||  || E465
|-
| rowspan=5 | Hydroxyalkyl
| rowspan=5 | [[Epoxide]]s
| [[Hydroxyethyl cellulose]] || [[Ethylene oxide]] || −CH<sub>2</sub>CH<sub>2</sub>OH || Cold/hot water-soluble || Gelling and thickening agent<ref name="Orlanducci-2022">{{cite journal |last1=Orlanducci |first1=Palmieri |title=Engineered surface for high performance electrodes on paper |journal=Applied Surface Science |date=2022 |volume=608 |article-number=155117 |doi=10.1016/j.apsusc.2022.155117}}</ref> ||
|-
| [[Hydroxypropyl cellulose]] (HPC) || [[Propylene oxide]] || −CH<sub>2</sub>CH(OH)CH<sub>3</sub> || Cold water-soluble || filming properties, coating properties, pharmaceuticals, cultural heritage restoration, electronic applications, cosmetic sector<ref name="Maita-2023"/><ref name="Orlanducci-2022"/><ref>{{cite journal |last1=Orlanducci |first1=Palmieri |title=A Sustainable Hydroxypropyl Cellulose-Nanodiamond Composite for Flexible Electronic Applications |journal=Gels |date=2022 |volume=12 |issue=8 |page=783 |doi=10.3390/gels8120783 |doi-access=free |pmid=36547307 |pmc=9777684 }}</ref><ref>{{cite journal |last1=Orlanducci |first1=Palmieri |title=Nanodiamond composites: A new material for the preservation of parchment |journal=Journal of Applied Polymer Science |date=2022 |volume=32 |issue=139 |article-number=e52742 |doi=10.1002/app.52742|bibcode=2022JAPS..139E2742P |s2cid=249654979 }}</ref><ref>{{cite journal |last1=Brunetti |first1=Polino |title=Nanodiamond-Based Separators for Supercapacitors Realized on Paper Substrates |journal=Energy Technology |date=2020 |volume=6 |issue=8 |article-number=1901233 |doi=10.1002/ente.201901233}}</ref>|| E463
|-
| [[Hydroxyethyl methyl cellulose]] || Chloromethane and ethylene oxide || −CH<sub>3</sub> or −CH<sub>2</sub>CH<sub>2</sub>OH || Cold water-soluble || Production of cellulose films ||
|-
| [[Hydroxypropyl methyl cellulose]] (HPMC) || Chloromethane and propylene oxide || −CH<sub>3</sub> or −CH<sub>2</sub>CH(OH)CH<sub>3</sub> || Cold water-soluble || Viscosity modifier, gelling, foaming, and binding agent || E464
|-
| [[Ethyl hydroxyethyl cellulose]] || Chloroethane and ethylene oxide || −CH<sub>2</sub>CH<sub>3</sub> or −CH<sub>2</sub>CH<sub>2</sub>OH ||  ||  || E467
|-
| Carboxyalkyl || Halogenated carboxylic acids || [[Carboxymethyl cellulose]] (CMC) || [[Chloroacetic acid]] || −CH<sub>2</sub>COOH || Cold/Hot water-soluble || Often used as its [[sodium]] [[salt (chemistry)|salt]], sodium carboxymethyl cellulose (NaCMC) || E466
|}

The sodium carboxymethyl cellulose can be [[cross-linked]] to give the [[croscarmellose sodium]] (E468) for use as a [[Excipient|disintegrant]] in pharmaceutical formulations. Furthermore, by the covalent attachment of thiol groups to cellulose ethers such as sodium carboxymethyl cellulose, ethyl cellulose, or hydroxyethyl cellulose [[Mucoadhesion|mucoadhesive]] and permeation enhancing properties can be introduced.<ref>{{cite journal|last1=Clausen|first1=A| last2=Bernkop-Schnürch|first2=A|title= Thiolated carboxymethylcellulose: in vitro evaluation of its permeation enhancing effect on peptide drugs |journal= Eur J Pharm Biopharm|date=2001|volume=51|issue=1|pages=25–32|doi=10.1016/s0939-6411(00)00130-2|pmid=11154900}}</ref><ref>{{cite journal|last1=Rahmat|first1=D|last2=Devina|first2=C|title= Synthesis and characterization of a cationic thiomer based on ethyl cellulose for realization of mucoadhesive tablets and nanoparticles |journal= International Journal of Nanomedicine|date=2022|volume=17|pages=2321–2334|doi=10.2147/IJN.S321467|pmid=35645561|pmc=9130100|s2cid=248952610|doi-access=free}}</ref><ref>{{cite journal|last1= Leonaviciute |first1=G|last2=Bonengel |first2=S | last3= Mahmood |first3=A|last4= Ahmad Idrees |first4=M|last5=Bernkop-Schnürch|first5=A|title= S-protected thiolated hydroxyethyl cellulose (HEC): Novel mucoadhesive excipient with improved stability |journal= Carbohydr Polym |date=2016|volume=144|pages=514–521|doi=10.1016/j.carbpol.2016.02.075|pmid=27083843}}</ref> Thiolated cellulose derivatives (see [[thiomer]]s) exhibit also high binding properties for metal ions.<ref>{{cite journal|last1=Leichner |first1=C|last2=Jelkmann|first2=M|last3=Bernkop-Schnürch|first3=A|title=Thiolated polymers: Bioinspired polymers utilizing one of the most important bridging structures in nature|journal= Advanced Drug Delivery Reviews|date=2019|volume=151-152|pages=191–221|doi=10.1016/j.addr.2019.04.007|pmid=31028759|s2cid=135464452}}</ref><ref>{{cite journal|last1=Seidi |first1=F|last2=Saeb|first2=MR|last3=Huang|first3=Y| last4=Akbari|first4=A|last5=Xiao|first5=H| title= Thiomers of chitosan and cellulose: Effective biosorbents for detection, removal and recovery of metal ions from aqueous medium |journal= The Chemical Record|date=2021|volume=21-152|issue=7|pages=1876–1896|doi=10.1002/tcr.202100068|pmid=34101343|s2cid=235368517}}</ref>

==Commercial applications==
[[File:Cellulose strand.svg|class=skin-invert-image|thumb|A strand of cellulose (conformation I<sub>α</sub>), showing the [[hydrogen bond]]s (dashed) within and between cellulose molecules.]]
{{see also|dissolving pulp|pulp (paper)}}
Cellulose for industrial use is mainly obtained from [[wood pulp]] and from [[cotton]].<ref name="Klemm-2005"/>
* Paper products: Cellulose is the major constituent of [[paper]], [[paperboard]], and [[card stock]]. [[Electrical insulation paper]]: Cellulose is used in diverse forms as insulation in transformers, cables, and other electrical equipment.<ref>{{cite journal |title=Cellulose as an insulating material |author=Kohman, GT |date=July 1939 |journal= Industrial and Engineering Chemistry |volume=31 |issue=7 |pages=807–817 |doi=10.1021/ie50355a005}}</ref>
* Fibres: Cellulose is the main ingredient of [[textile]]s. [[Cotton]] and synthetics (nylons) each have about 40% market by volume. Other [[plant fibre]]s (jute, sisal, hemp) represent about 20% of the market. [[Rayon]], [[cellophane]], and other "regenerated [[cellulose fibre]]s" are a small portion (5%).{{citation needed|date=January 2025}}
* Consumables: [[Microcrystalline cellulose]] ([[E number|E460i]]) and powdered cellulose (E460ii) are used as inactive [[Excipient#Fillers and diluents|fillers]] in drug tablets<ref>
{{Cite book |isbn       = 978-0-8247-8210-8
 |page       = [https://archive.org/details/excipienttoxicit103wein/page/210 210]
 |last       = Weiner
 |first      = Myra L.
 |author2    = Kotkoskie, Lois A.
 |title      = Excipient Toxicity and Safety
 |year       = 2000
 |place      = New York
 |publisher  = Dekker
 |url-access = registration
 |url        = https://archive.org/details/excipienttoxicit103wein/page/210
}}</ref> and a wide range of soluble cellulose derivatives, E numbers E461 to E469, are used as emulsifiers, thickeners, and stabilizers in processed foods. Cellulose powder is, for example, used in processed cheese to prevent caking inside the package. Cellulose occurs naturally in some foods and is an additive in manufactured foods, contributing an indigestible component used for texture and bulk, potentially aiding in [[defecation]].<ref>{{cite journal|pmc=3614039|year=2011|last1=Dhingra|first1=D|title=Dietary fibre in foods: A review|journal=Journal of Food Science and Technology|volume=49|issue=3|pages=255–266|last2=Michael|first2=M|last3=Rajput|first3=H|last4=Patil|first4=R. T.|doi=10.1007/s13197-011-0365-5|pmid=23729846}}</ref>
* Building material: Hydroxyl bonding of cellulose in water produces a sprayable, moldable material as an alternative to the use of plastics and resins. The recyclable material can be made water- and fire-resistant. It provides sufficient strength for use as a building material.<ref>{{cite web |url=http://www.gizmag.com/zeoform-cellulose-water/28796 |title=Zeoform: The eco-friendly building material of the future? |publisher=Gizmag.com |access-date=August 30, 2013 |date=August 30, 2013 |archive-date=October 28, 2013 |archive-url=https://web.archive.org/web/20131028082032/http://www.gizmag.com/zeoform-cellulose-water/28796/ |url-status=live }}</ref> [[Cellulose insulation]] made from recycled paper is becoming popular as an environmentally preferable material for [[building insulation]]. It can be treated with [[boric acid]] as a [[fire retardant]].{{citation needed|date=January 2025}}
* Miscellaneous: Cellulose can be converted into [[cellophane]], a thin transparent film. It is the base material for the [[celluloid]] that was used for photographic and movie films until the mid-1930s. Cellulose is used to make water-soluble [[adhesive]]s and [[binder (material)|binders]] such as [[methyl cellulose]] and [[carboxymethyl cellulose]] which are used in [[wallpaper paste]]. Cellulose is further used to make [[hydrophilic]] and highly absorbent [[sponge (tool)|sponges]]. Cellulose is the raw material in the manufacture of [[nitrocellulose]] (cellulose nitrate) which is used in [[smokeless powder|smokeless gunpowder]].{{citation needed|date=January 2025}}
* Pharmaceuticals: Cellulose derivatives, such as [[microcrystalline cellulose]] (MCC), have the advantages of retaining water, being a [[stabilizer (chemistry)|stabilizer]] and [[thickening agent]], and in reinforcement of drug tablets.<ref>{{cite journal|pmid=24993785|year=2014|last1=Thoorens|first1=G|title=Microcrystalline cellulose, a direct compression binder in a quality by design environment--a review|journal=International Journal of Pharmaceutics|volume=473|issue=1–2|pages=64–72|last2=Krier|first2=F|last3=Leclercq|first3=B|last4=Carlin|first4=B|last5=Evrard|first5=B|doi=10.1016/j.ijpharm.2014.06.055|doi-access=free}}</ref>

===Aspirational===
Energy crops: {{Main|Energy crop}} The major [[combustion|combustible]] component of non-food [[energy crop]]s is cellulose, with [[lignin]] second. Non-food energy crops produce more usable energy than edible energy crops (which have a large [[starch]] component), but still compete with food crops for agricultural land and water resources.<ref>Holt-Gimenez, Eric (2007). ''Biofuels: Myths of the Agrofuels Transition''. ''Backgrounder''. [[Institute for Food and Development Policy]], Oakland, CA. 13:2 {{cite web |url=http://www.foodfirst.org/en/node/2638 |access-date=September 5, 2013 |title=Biofuels - Myths of the Agrofuels Transition: Parts I & II |archive-date=November 16, 2009 |archive-url=https://web.archive.org/web/20091116164308/http://www.foodfirst.org/en/node/2638 |url-status=dead|first=Eric|last=Holt-Giménez}} {{cite web |url=http://www.foodfirst.org/fr/node/1712 |title=Biofuels - Myths of the Agrofuels Transition: Parts I & II |access-date=September 5, 2013 |url-status=dead |archive-url=https://web.archive.org/web/20130906121836/http://www.foodfirst.org/fr/node/1712 |archive-date=September 6, 2013|first=Eric|last=Holt-Giménez |date=November 13, 2009}}</ref> Typical non-food energy crops include [[hemp|industrial hemp]], [[switchgrass]], ''[[Miscanthus]]'', ''Salix'' ([[willow]]), and ''Populus'' ([[Populus|poplar]]) species. A strain of ''[[Clostridium]]'' bacteria found in zebra dung can convert nearly any form of cellulose into [[butanol fuel]].<ref>MullinD,  Velankar  H.2012.Isolated  bacteria,  methods  for  use,  and  methods  for isolation.World patent WO 2012/021678 A2</ref><ref>{{cite journal|display-authors=etal|last1=Sampa Maiti |title=Quest for sustainable bio-production and recovery of butanol as a promising solution to fossil fuel |journal=Energy Research |date=December 10, 2015 |volume=40 |issue=4 |pages=411–438 |doi=10.1002/er.3458|s2cid=101240621 |doi-access=free }}</ref><ref>{{cite web |url=http://tulane.edu/news/releases/pr_082511.cfm |title=Cars Could Run on Recycled Newspaper, Tulane Scientists Say |author=Hobgood Ray, Kathryn |date=August 25, 2011 |work=Tulane University news webpage |publisher=[[Tulane University]] |access-date=March 14, 2012 |archive-url=https://web.archive.org/web/20141021085626/http://tulane.edu/news/releases/pr_082511.cfm |archive-date=October 21, 2014 |url-status=dead }}</ref><ref>{{cite web |url=http://www.greenprophet.com/2012/01/zebra-butanol-biofuel/ |title=Put a Zebra in Your Tank: A Chemical Crapshoot? |author=Balbo, Laurie |date=January 29, 2012 |publisher=Greenprophet.com |access-date=November 17, 2012 |archive-date=February 13, 2013 |archive-url=https://web.archive.org/web/20130213020525/http://www.greenprophet.com/2012/01/zebra-butanol-biofuel/ |url-status=live }}</ref>

Another possible application is as [[Insect repellent]]s.<ref>{{Cite news |last=Thompson |first=Bronwyn |date=April 13, 2023 |title=Natural treatment could make you almost invisible to mosquito bites |language=en-US |work=New Atlas |url=https://newatlas.com/science/cellulose-nanocrystals-invisible-mosquitos/ |access-date=April 17, 2023 |archive-date=April 17, 2023 |archive-url=https://web.archive.org/web/20230417154815/https://newatlas.com/science/cellulose-nanocrystals-invisible-mosquitos/?utm_source=New+Atlas+Subscribers&utm_campaign=f043af663f-EMAIL_CAMPAIGN_2023_04_13_01_37&utm_medium=email&utm_term=0_65b67362bd-f043af663f-%5BLIST_EMAIL_ID%5D |url-status=live }}</ref>

====Dung-geneering====
Cellulose has been extracted from [[cow dung]] using pressurized spinning from a horizontal vessel capable of structuring small structure nano-fibers.<ref>{{cite journal | last1=Dai | first1=Yanqi | last2=Sun | first2=Dongyang | last3=O'Rourke | first3=Dominic | last4=Velusamy | first4=Sasireka | last5=Sundaram | first5=Senthilarasu | last6=Edirisinghe | first6=Mohan | title=Harnessing cow manure waste for nanocellulose extraction and sustainable small-structure manufacturing | journal=Journal of Cleaner Production | date=2025 | volume=509 | article-number=145530 | doi=10.1016/j.jclepro.2025.145530 | bibcode=2025JCPro.50945530D | url=https://www.sciencedirect.com/science/article/pii/S0959652625008807 | doi-access=free }}</ref>

== See also ==
* [[Gluconic acid]]
* [[Isosaccharinic acid]], a degradation product of cellulose
* [[Lignin]]
* [[Zeoform]]

== References ==
{{reflist|30em}}

== External links ==
{{Commons category|Cellulose}}
* {{cite EB1911|wstitle=Cellulose |volume=5 |short=x}}
* [https://web.archive.org/web/20090426122947/http://www.cermav.cnrs.fr/glyco3d/lessons/cellulose/index.html Structure and morphology of cellulose] by Serge Pérez and William Mackie, CERMAV-[[CNRS]]
* [https://web.archive.org/web/20051001072830/http://www.lsbu.ac.uk/water/hycel.html Cellulose], by Martin Chaplin, [[London South Bank University]]
* [https://web.archive.org/web/20050426105859/http://msa.ars.usda.gov/la/srrc/fb/ca.html Clear description of a cellulose assay method] at the Cotton Fiber Biosciences unit of the [[United States Department of Agriculture|USDA]].
* [http://www.technologyreview.com/read_article.aspx?ch=infotech&sc=&id=17127&pg=1 Cellulose films could provide flapping wings and cheap artificial muscles for robots] – TechnologyReview.com

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[[Category:Cellulose| ]]
[[Category:Excipients]]
[[Category:Papermaking]]
[[Category:Polysaccharides]]
[[Category:E-number additives]]