ASTM D1695-07(2019)

Standard Terminology of Cellulose and Cellulose Derivatives

SCOPE
1.1 This terminology standard contains terms, definition of terms, descriptions of terms, nomenclature, and explanations of acronyms and symbols specifically associated with standards under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications; Subcommittee D01.36 on Cellulose and Cellulose Derivatives.  
1.2 This terminology is divided into three classes as follows:    
Section  
Cellulosic Materials and Constituents  
3.1  
Chemical Modifications and Derivatives of Cellulose  
3.2  
Properties of Cellulose and Associated Concepts that are
applicable to both Sections 3.1 and 3.2  
3.3  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Nov-2019
• ICS: 01.040.85 - Paper technology (Vocabularies)
• ICS: 85.040 - Pulps
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.36 - Cellulose and Cellulose Derivatives

Relations

• Replaces: ASTM D1695-07(2012) - Standard Terminology of Cellulose and Cellulose Derivatives
• Effective Date: 01-Dec-2019
• Referred By: ASTM D5896-96(2019)e1 - Standard Test Method for Carbohydrate Distribution of Cellulosic Materials
• Effective Date: 01-Dec-2019
• Referred By: ASTM D16-23 - Standard Terminology for Paint, Related Coatings, Materials, and Applications
• Effective Date: 01-Dec-2019
• Referred By: ASTM D6188-17(2022) - Standard Test Method for Viscosity of Cellulose by Cuprammonium Ball Fall
• Effective Date: 01-Dec-2019
• Referred By: ASTM D6942-03(2019) - Standard Test Method for Stability of Cellulose Fibers in Alkaline Environments
• Effective Date: 01-Dec-2019
• Referred By: ASTM E284-22 - Standard Terminology of Appearance
• Effective Date: 01-Dec-2019
• Referred By: ASTM D6389-17 - Standard Practice for Tests to Evaluate the Chemical Resistance of Geotextiles to Liquids
• Effective Date: 01-Dec-2019
• Referred By: ASTM D5012-20 - Standard Practice for Preparation of Materials Used for the Collection and Preservation of Atmospheric Wet Deposition
• Effective Date: 01-Dec-2019
• Referred By: ASTM D6213-17 - Standard Practice for Tests to Evaluate the Chemical Resistance of Geogrids to Liquids
• Effective Date: 01-Dec-2019
• Referred By: ASTM D2270-10(2016) - Standard Practice for Calculating Viscosity Index from Kinematic Viscosity at 40 °C and 100 °C
• Effective Date: 01-Dec-2019

Overview

ASTM D1695-07(2019): Standard Terminology of Cellulose and Cellulose Derivatives is an internationally recognized terminology standard developed by ASTM Committee D01, specifically Subcommittee D01.36. This document provides clear definitions, descriptions, nomenclature, and explanations of acronyms and symbols relevant to cellulose materials, their chemical modifications, and associated properties. The standard enhances communication and understanding in industries and research involving cellulose, supporting consistent terminology for technical, commercial, and academic applications.

Key Topics

The terminology standard is structured into three main classes, each focusing on a core aspect of cellulose:

• Cellulosic Materials and Constituents
  Covers key terms that describe natural and purified forms of cellulose, such as alpha-cellulose, beta-cellulose, cellulose I-IV, holocellulose, hemicellulose, and structural features like fibrils and crystallinity.
• Chemical Modifications and Derivatives
  Defines concepts related to chemically altered cellulose, including cellulose esters (e.g., cellulose acetate, cellulose nitrate), cellulose ethers (e.g., methylcellulose, carboxymethylcellulose), and regenerated cellulose (e.g., rayon, cellophane).
• Properties and Associated Concepts
  Explains properties relevant to both raw and modified forms of cellulose, such as degree of polymerization, viscosity, crystallinity, moisture regain, density, and reactivity.

Applications

ASTM D1695-07(2019) serves several practical functions across diverse industries, ensuring precision and uniformity in discussing cellulose and its derivatives:

• Paper and Pulp Industry:
  Supports standard communication for manufacturing, testing, and quality control of paper, pulp, and fiber products. Examples include categorizing pulps (kraft, sulfite), specifying cellulose purity, and defining standards for raw materials used in paper, cellophane, and rayon production.
• Coatings and Plastics:
  Provides standardized definitions for cellulose derivatives used in paints, coatings, lacquers, and plastics, such as cellulose acetate, propionate, and nitrate.
• Chemical Manufacturing:
  Streamlines the specification and evaluation of cellulose materials intended for further chemical modification (ethers, esters) or for the production of specialty products like films, plastics, or pharmaceutical excipients.
• Research and Development:
  Assists researchers in adopting common language for reporting results, comparing materials, and interpreting scientific literature on cellulose chemistry and technology.
• Quality Assurance:
  Facilitates regulatory compliance and accurate documentation by defining acronyms, test methods, and symbols widely used in industry standards and international trade.

Related Standards

This terminology standard references and complements several other important documents and industry guidelines:

• TAPPI Method T203 om-93: For analysis of alpha-, beta-, and gamma-cellulose in pulp.
• ASTM D1696: Test methods for determining the solubility of cellulose in alkali.
• Annual Book of ASTM Standards, Vol 06.03: Contains a comprehensive list of applicable ASTM standards related to paints, coatings, and associated materials.

Complying with ASTM D1695-07(2019) ensures alignment with international principles as outlined by the World Trade Organization's TBT Committee, promoting compatibility and global acceptance in cellulose-related industries.

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Keywords: cellulose terminology, cellulose derivatives, ASTM D1695, pulp and paper standards, chemical cellulose, cellulose esters, cellulose ethers, international standard, cellulosic materials, cellulose properties, quality control, cellulose applications

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D1695 − 07 (Reapproved 2019)
Standard Terminology of
Cellulose and Cellulose Derivatives
This standard is issued under the fixed designation D1695; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope alpha-cellulose—(1) Historically, a term used to indicate the
pure, relative undegraded cellulose found in pulps. (2)
1.1 This terminology standard contains terms, definition of
Alpha-cellulosecontentisoftenmeasuredbyTAPPIMethod
terms,descriptionsofterms,nomenclature,andexplanationsof
T203 om-93 where alpha-cellulose is that portion of the
acronyms and symbols specifically associated with standards
pulp which does not dissolve under the test conditions.
under the jurisdiction of ASTM Committee D01 on Paint and
Related Coatings, Materials, and Applications; Subcommittee
alpha pulps—see chemical cellulose.
D01.36 on Cellulose and Cellulose Derivatives.
araban—a pentosan yielding essentially only arabinose on
1.2 This terminology is divided into three classes as fol-
hydrolysis.
lows:
arabinogalactan—a polysaccharide consisting of arabinose
Section
and galactose units, like the water-soluble polysaccharide of
Cellulosic Materials and Constituents 3.1
Chemical Modifications and Derivatives of Cellulose 3.2
larch.
Properties of Cellulose and Associated Concepts that are
applicable to both Sections 3.1 and 3.2 3.3
arabinose—a pentose that occurs as one of the sugar units in
1.3 This international standard was developed in accor-
some hemicelluloses.
dance with internationally recognized principles on standard-
arabinomethylglucuronoxylan—a hemicellulose containing
ization established in the Decision on Principles for the
arabinose, 4-O-methylglucuronic acid, and xylose groups in
Development of International Standards, Guides and Recom-
its structure.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
beta-cellulose—(1) Historically, a term used to indicate impu-
rities of moderate chain lengths found in pulps, predomi-
2. Referenced Documents
nately degraded cellulose. (2) Beta-cellulose content, as
2.1 The numerous ASTM Standards to which this standard
measured by TAPPI Method T203 om-93, is the pulp
applies are found in the Annual Book of ASTM Standards,Vol
fraction soluble in caustic, which precipitates upon acidifi-
06.03.
cation.
2.2 TAPPI Standards:
carbohydrates not cellulose—the noncellulosic carbohy-
TAPPI Method T203 om-93Alpha-, Beta- and Gamma-
drates of a cellulosic material.
Cellulose in Pulp
cellophane pulps—pulps used in the manufacture of
3. Terminology
cellophane, and subject to various specifications by the
3.1 Cellulosic Materials and Constituents
manufacturers, including those of purity, moisture content,
sheet properties, and viscosity.
acetylation pulps—pulpsusedinthemanufactureofcellulose
acetate or other esters, and subject to various specifications
cellulose—(1) the main solid constituent of woody plants; it
by the manufacturers, including those of purity, moisture
occurs widely elsewhere in the vegetable kingdom, and to a
content, sheet properties, and viscosity.
smallextentintheanimalkingdom.(2)chemically,cellulose
is β-1-4 glucan of high degree of polymerization. It is
1 desirable to apply “cellulose” to this material only and to
This terminology is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, andApplications and is the direct responsibility of designate the predominantly cellulosic residue obtained by
Subcommittee D01.36 on Cellulose and Cellulose Derivatives.
subjecting woody tissues to various pulping processes as
Current edition approved Dec. 1, 2019. Published December 2019. Originally
“cellulosic residues,” “cellulosic pulps,” or the like.
approved in 1959. Last previous edition approved in 2012 as D1695–07 (2012).
DOI: 10.1520/D1695-07R19.
cellulose I—the crystalline modification of cellulose that
Available from TechnicalAssociation of the Pulp and Paper Industry (TAPPI),
15 Technology Parkway South, Norcross, GA 30092, http://www.tappi.org. normally occurs in nature.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D1695 − 07 (2019)
cellulose II—the crystalline modification of cellulose that is glucan—a macromolecular substance that can be hydrolyzed
found in mercerized cellulose, in regenerated cellulose, and to give almost exclusively glucose.
in cellulose produced by the hydrolysis of various cellulose
glucomannan—a hemicellulose consisting essentially of glu-
derivatives.
cose and mannose.
cellulose III—a crystalline modification of cellulose produced
glucuronoxylan—a common designation for the xylose-
by treatment, under certain conditions, with ammonia or
containing hardwood hemicelluloses. (see also methylglu-
sometimes by amines. The method of removing the reagent
curonoxylan)
determines the modification produced.
hemicellulose—any of a number of cell-wall polysaccharides
cellulose IV—a crystalline modification of cellulose produced
thatareremovablebyextractionwithaqueousalkaliandthat
by heat treatment of cellulose II.
may be hydrolyzed by boiling with dilute acids to give
constituent monosaccharide units; any of the noncellulosic
cellulose X—a crystalline modification of cellulose produced
cell-wall polysaccharides.
by treatment of cellulose with strong hydrochloric acid or
phosphoric acid.
hexosan—frequently used in contradistinction to pentosan, for
a polysaccharide consisting mainly of hexose units.
cellulose, purified cotton—see cotton cellulose, purified.
cellulose, purified wood—see wood cellulose, purified.
holocellulose—the total polysaccharide fraction of extractive-
chemical cellulose—a chemically purified cellulosic material free wood. The method of isolation or of determination
that is intended for chemical treatment to produce deriva-
should always be given.
tives.
kraft pulp—pulp cooked by the alkaline liquor consisting
chemical cotton—chemical cellulose prepared from cotton; essentially of a mixture of caustic soda and sodium sulfide.
Themake-upchemicalistraditionallysodiumsulfate,which
generally, but not necessarily, cotton linters.
is reduced to the sulfide in the chemical recovery process;
chemical pulps—in the paper industry, pulps produced by
hence the alternative designation, sulfate pulp.
chemical processes, as contrasted to those produced by
lignin—that part of plant material which is not saccharified by
mechanical processes. (see also chemical wood pulp)
the action of 72% sulfuric acid or 42% hydrochloric acid,
chemical wood pulp—a term used in the paper industry for
after the resins, waxes, and tannins have been removed.
pulps obtained by digestion of wood with solutions of
linters—theshortfibrousmaterialadheringtocottonseedafter
various chemicals.
the ginning operation.After removal from the seed it is used
DISCUSSION—This term, which refers to pulp produced and purified
by chemical processes, should not be confused with chemical cellulose to a limited extent as a fibrous raw material for special
which refers to pulp that is to be used in chemical processes.
papers.Theprincipaluse,however,isforchemicalcellulose,
that is, as the raw material for the manufacture of cellulose
cotton cellulose, purified—chemical cellulose from cotton
derivatives.
fiber or linters. (see also chemical cotton)
mannan—strictly, a polysaccharide composed entirely of
cotton linters—see linters.
mannose units, but used conventionally to distinguish the
dissolving pulps—see pulps, dissolving.
hexosan wood hemicelluloses from the pentosans (xylan).
extractives—compounds occurring in plant materials, but not
(see also galactoglucomannan and glucomannan)
forming part of the structural elements, that are removed
mannogalactan—see galactomannan.
with neutral solvents such as ether, alcohol, and water.
methylglucuronoxylan—themainhemicelluloseofhardwood
galactan—a polysaccharide composed essentially of galactose
pulps; a polysaccharide containing xylose and 4-O-
units. (see also arabinogalactan)
methylglucuronic acid groups. In the wood it is partially
acetylated.
galactoglucomannan—one of the hemicelluloses of
softwoods, containing three types of sugar units—galactose,
nitrating pulps—pulps used for the manufacture of cellulose
glucose, and mannose.
nitrate and subject to various specifications by the
manufacturers, including those of alpha-cellulose content
galactomannan—a polysaccharide containing galactose and
and viscosity.
mannoseunits.Galactomannansusuallyhavealongchainof
mannose units with galactose side chains and are found in
oligosaccharides—polymeric carbohydrates containing rela-
seed gums (guar, locust bean).
tively few (compared to the polysaccharides) sugar units
connectedbyglycosidallinkages.Twotonineunitshasbeen
gamma-cellulose—(1) Historically, a term used to indicate
suggestedasasuitablerange.Forlongerchainsthepolymers
impurities of short chain lengths found in pulps, predomi-
cannot be readily separated into individual molecular spe-
nately hemicelluloses. (2) Gama-cellulose content, as mea-
cies.
sured by TAPPI Method T203 om-93, is the pulp fraction
soluble in caustic, which remains in solution upon acidifi- pectic substrates—complex polysaccharides containing a
cation. large proportion of galacturonic acid units.
D1695 − 07 (2019)
pectins—colorless, amorphous, water-soluble polysaccharides carboxymethylcellulose, CMC—the common name for a
occurringinplanttissuesthatyieldpecticacidandmethanol cellulose ether of glycolic acid. It is usually marketed as a
on hydrolysis. water-soluble sodium salt, more properly called sodium
carboxymethylcellulose. In the early literature, it is some-
pentosans—one of the groups of amorphous carbohydrates
times called cellulose glycolate or cellulose glycolic acid.
included under the general term “hemicellulose.” Pentosans
yield principally pentoses on acid hydrolysis. The principal cellulose acetate—in the broad sense, any of several esters of
pentosan in wood is xylan. cellulose and acetic acid. (see also cellulose triacetate)
polyuronides—polysaccharides containing uronic acid cellulose acetate butyrate—a mixed ester of cellulose con-
groups. taining both acetate and butyrate groups.
pulps, dissolving—chemical cellulose from wood pulp. cellulose acetate phthalate—a mixed ester of cellulose con-
taining both acetate and phthalate groups.
pulps for chemical conversion—chemical cellulose from
wood pulp. cellulose acetate propionate—a mixed ester of cellulose
containing both acetate and propionate groups.
pulps for manufacture of cellulose derivatives—chemical
cellulose from wood pulp. cellulose derivative—a substance derived from cellulose by
substitution of one or more of the hydroxyl groups with
purified cotton cellulose—see cotton cellulose, purified.
some other radical. Most derivatives are ethers or esters.
purified wood cellulose—see wood cellulose, purified.
cellulose esters—derivativesofcelluloseinwhichoneormore
R —the portion of a cellulose pulp that is insoluble in 10%
of the hydroxyl hydrogens have been replaced acyl groups.
sodium hydroxide using Test Method D1696 or its equiva-
lent.
cellulose ethers—derivatives of cellulose in which one or
DISCUSSION—R indicates the pure, relatively undegraded cellulose
moreofthehydroxylhydrogenshavebeenreplacedbyalkyl
content of pulps, and as such may be compared to alpha-cellulose,
groups.
although they are determined by different test procedures.
cellulose lacquer—a liquid coating composition containing as
rayon pulps—pulps used in the manufacture of rayon, and
the basic film-forming ingredient a cellulose ester or ether
subject to various specifications by the manufacturers, in-
and plasticizers with or without resins or pigments.
cluding those of purity, moisture content, sheet properties,
and viscosity.
cellulose mixed ester—a cellulose ester containing more than
one type of acyl group.
S —the portion of a cellulose pulp that is soluble in 10%
sodium hydroxide using Test Method D1696, or its equiva-
cellulose nitrate—any of various nitrate esters of cellulose.
lent.
DISCUSSION—Cellulose nitrate is often and erroneously called “nitro-
DISCUSSION—S is considered to contain both hemicellulose and
cellulose.”
degraded, short chain length cellulose (see R ).
cellulose plastics—plastics based on cellulose compounds,
S —the portion of a cellulose pulp that is soluble in 18%
such as esters (cellulose acetate) and ethers (ethylcellulose).
sodium hydroxide using Test Method D1696, or its equiva-
cellulose propionate—any ester of cellulose with propionic
lent.
DISCUSSION—S isconsideredtobemainlyhemicelluloses,andmay
acid.
be compared to gamma-cellulose, although they are determined by
cellulose sodium glycolate—see carboxymethyl cellulose.
different test procedures.
cellulose triacetate—that form of cellulose acetate in which
S –S —an estimate of the portion of degraded cellulose in a
10 18
the degree of substitution approaches 3 sufficiently that the
pulp obtained by subtracting S from S .
18 10
product is not soluble in acetone.
DISCUSSION—Some workers use S to S as an estimate of the
10 18
hemicellulose content of pulps, and may be compared to gamma-
cellulose xanthates—the salts of cellulose xanthic acid.
cellulose, although they are determined by different test procedures.
Commonly, cellulose xanthate refers to sodium cellulose
sulfate pulp—see kraft pulp.
xanthate, the essential constituent of the viscose solution,
sulfite pulp—wood pulp produced by cooking with a sulfite
from which viscose rayon is spun.
liquormadebydissolvingsulfurdioxideinanaqueousbase.
dope—a composition, usually a cellulose lacquer, for applica-
wood cellulose, purified—chemical cellulose from wood.
tion on textiles and leathers. Also a very viscous crude
reaction product, as acetylation dope.
xylan—apentosangivingalmostexclusivelyxyloseonhydro-
lysis.
ethylcellulose—any of several ethyl ethers of cellulose. The
one most generally used in industry has sufficient substitu-
3.2 Chemical Modifications and Derivatives of Cellulose
tion to be soluble in organic solvents.
hydrocelluloses—water-insoluble products of the hydrolysis
Annual Book of ASTM Standards, Vol 06.03. of cellulose with acids. They are molecularly heterogeneous
D1695 − 07 (2019)
in the sense that they are composed of molecules varying in viscose—a solution of sodium cellulose xanthate prepared by
degree of polymerization. The average degree of polymer- dissolving the reaction product formed by the interaction of
ization (DP) and the DPdistribution depend on the nature of carbon disulfide and alkali cellulose in an aqueous solution
the acid treatment and of the original cellulose. The term of sodium hydroxide. Viscose is used mainly in the manu-
may also be applied to any insoluble polysaccharide so facture of rayon or cellophane, where it is extruded through
formed and separated as a more or less homogeneous fine openings of the proper shape into a coagulating bath.
fraction from the mixture of products, but the singular form
3.3 Properties of Cellulose and Associated Concepts
“hydrocellulose” should not be used without an article, to
accessibility—the fraction of total cellulose present that is
avoid the implication of a molecularly homogeneous spe-
accessible to certain reagents under certain specified condi-
cies.
tions. The conditions of determination should always be
(2-hydroxyethyl)cellulose—any of several cellulose ethers in
indicated.
which some of the hydroxyl groups have been substituted
acetylation—substitution of an acetyl radical for an active
withhydroxyethylgroups.Hydroxyethylcellulose,exceptat
hydrogen. Specifically, formation of cellulose acetate from
very low degrees of substitution, is water-soluble.
cellulose.
(2-hydroxyethyl)ethylcellulose—a mixed ether of cellulose
acetyl groups—the characteristic groups of acetic acid;
containing both hydroxyethyl and ethyl groups.
CH CO—.
(2-hydroxyethyl)methylcellulose—a mixed ether of cellulose
acyl groups—radicals derived from carboxylic acids by re-
containing both hydroxyethyl and methyl groups.
moval of the hydroxyl group.
(2-hydroxypropyl)methylcellulose—a mixed ether of cellu-
acid groups—functionalgroupshavingthepropertiesofacids.
lose containing both hydroxypropyl and methyl groups.
In cellulose and its derivatives, these are usually carboxyl
ionic cellulose ethers—those water-soluble cellulose ethers
groups.
which contain ionizable groups, in more than trace amounts.
aging—ingeneral,thechangeofpropertieswiththepassageof
Sodium carboxymethyl cellulose is an example.
time. Specifically, the changes occurring in shredded alkali
lacquer—see cellulose lacquer.
cellulose when allowed to stand exposed to air.
methylcellulose—any of several methyl ethers of cellulose. air-dry—a condition applied to paper or pulp whereby its
Commercially, the water-soluble ether (degree of substitu-
moisture content is in equilibrium with the atmospheric
tion approximately 1.5 to 2.0). conditionstowhichitisexposed.Accordingtotradecustom,
pulps are generally understood to be air dry when they
methylethylcellulose—a cellulose ether containing both
contain 10% of moisture, for example, a pound of air-dry
methyl and ethyl groups.
pulp contains 0.9 lb of oven-dry pulp and 0.1 lb of moisture
(see STP 60-B).
microcrystalline cellulose—a commercial name for cellulose
thathasbeenhydrolyzedtothelimitingDPandthatconsists
alcohol-benzene solubility—solubility of a cellulosic pulp in
essentially of microcrystals.
a mixture of ethanol and benzene. The term is without
precise meaning unless complete specification of an analyti-
nitrocellulose—see cellulose nitrate.
cal procedure is attached explicitly or implicitly.
nonionic cellulose ethers—thatclassofcelluloseetherswhich
aldehyde groups—carbonylgroupstowhichahydrogenatom
does not contain any ionizable groups.
is attached; the first oxidation stage of an alcohol;— CHO.
oxycelluloses—water-insoluble substances formed by the ac-
alkali resistance—for a cellulosic pulp, the fraction insoluble
tionofoxidizingagentsoncellulose.Thechemicalnatureof
in alkali, usually sodium hydroxide, of a fixed concentration
oxycelluloses varies with the oxidant used, and the type is
under specified conditions. The term is without precise
indicatedbyattachingthenameoftheoxidantadjectivallyto
meaning unless complete specification of an analytical
“oxycelluloses” as in “hypochlorite oxycelluloses.” Any
procedureisattachedexplicitlyorimplicitly.(seealso alkali
such mixture is “an oxycellulose” and the word should not
solubility)
be used in the singular without either the definite or
indefinite article. In many respects, the phrases “oxidized
alkali solubility—foracellulosicpulp,thefractioninalkaliof
cellulose” or “partially oxidized cellulose” are preferable.
afixedconcentrationunderspecifiedconditions.Thistermis
without precise meaning unless complete specification of an
propylene glycol ether of methylcellulose—see (2-
analytical procedure is attached explicitly or implicitly.
hydroxypropyl)methylcellulose.
Some related terms imply at least a partial specification, for
regenerated cellulose—cellulose regenerated from a solution example, “ten percent potassium hydroxide solubility” or
of cellulose or from a cellulose derivative.
“nondilution alkali solubility.”
sodium carboxymethylcellulose—see carboxymethylcellu- alkali stability—for a cellulosic pulp, resistance to strength
lose. loss due to exposure to alkaline environments.
D1695 − 07 (2019)
alkali staining—discoloration caused by the presence of an materials) treated under specified conditions with an excess
alkali. ofcupricsolution.Thecoppernumberisanindicationofthe
relative number of reducing groups in the pulp or paper.
alkyl groups—monovalent aliphatic radicals derived from
aliphatic hydrocarbons by removal of a hydrogen. cross linking—the reaction of a difunctional molecule with
each of two molecules of a polymer. This change of the
amorphous regions—those regions within a cellulosic mate-
polymer from linearity produces profound changes in the
rial which, on the basis of X-ray diffraction or other suitable
physical properties.
technique,donotshowanyevidenceofcrystallinestructure.
The technique should be specified. crystalline regions—see crystallinity.
anhydroglucose units—the repeating unit of many crystallinity—a regular arrangement of the atoms of a solid in
polysaccharides, including cellulose; since the glucose mol-
space. In most polymers, including cellulose, this state is
ecules have combined with elimination of water, the unit is usually imperfectly achieved. The crystalline regions (or-
called “anhydroglucose” rather than “glucose.”
deredregions)aresubmicroscopicvolumesinwhichthereis
more or less regularity of arrangement of the component
ash—t
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