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EC / List no.: 617-129-9
CAS no.: 8062-15-5
Lignin sulfonate is a natural material derived from lignin.
Lignin sulfonate is a by-product of the wood pulping process that is known for its binding, dispersing, and emulsifying properties.
Lignin sulfonates have a wide variety of applications.
In agriculture, lignin sulfonate can be used as part of crop production as a plant and soil amendment and a floatation agent.
Lignin sulfonate can also be used as a pellet binder.
Lignin sulfonates (LS) are water-soluble anionic polyelectrolyte polymers: they are byproducts from the production of wood pulp using sulfite pulping.
Most delignification in sulfite pulping involves acidic cleavage of ether bonds, which connect many of the constituents of lignin.
Sulfonated lignin (SL) refers to other forms of lignin by-product, such as those derived from the much more popular Kraft process, that have been processed to add sulfonic acid groups.
The two have similar uses and are commonly confused with each other, with SL being much cheaper.
LS and SL both appear as free-flowing powders; the former is light brown while the latter is dark brown.
Lignin sulfonate have very broad ranges of molecular mass (they are very polydisperse).
A range of from 1,000–140,000 Da has been reported for softwood Lignin sulfonates with lower values reported for hardwoods.
Sulfonated Kraft lignin tend to have smaller molecules at 2,000–3,000 Da.
SL and LS are non-toxic, non-corrosive, and biodegradable.
A range of further modifications may be applied to LS and SL, including oxidation, hydroxymethylation, sulfomethylation, and a combination thereof.
Preparation
Lignin sulfonates
Lignin sulfonates are recovered from the spent pulping liquids (red or brown liquor) from sulfite pulping.
Ultrafiltration can also be used to separate Lignin sulfonates from the spent pulping liquid.
AA list of CAS numbers for the various metal salts of Lignin sulfonate is available.
The electrophilic carbocations produced during ether cleavage react with bisulfite ions (HSO3−) to give sulfonates.
R-O-R' + H+ → R+ + R'OH
R+ + HSO3− → R-SO3H
The primary site for ether cleavage is the α-carbon (carbon atom attached to the aromatic ring) of the propyl (linear three carbon) side chain.
The following structures do not specify the structure since lignin and its derivatives are complex mixtures: the purpose is to give a general idea of the structure of Lignin sulfonates.
The groups R1 and R2 can be a wide variety of groups found in the structure of lignin.
Sulfonation occurs on the side chains, not on the aromatic ring like in p-toluenesulfonic acid.
Kraft lignin from black liquor, which is produced in much higher amounts, may be processed into sulfonated lignin.
The lignin is first precipitated by acidifying the liquor with CO2 then washed.
(Other methods for isolation exist.)
Reaction with sodium sulfite or sodium bisulfite and an aldehyde under a basic environment completes sulfonation.
Here the sulfonic acid groups end up on the aromatic ring instead of the aliphatic sidechain.
Uses:
Lignin sulfonate have a wide variety of applications.
They are used to stably disperse pesticides, dyes, carbon black, and other insoluble solids and liquids into water.
As a binder Lignin sulfonate suppresses dust on unpaved roads.
Lignin sulfonate is also a humectant and a in water treatment.
Chemically, it may be used as a tannin for tanning leather and as a feedstock for a variety of products.
Dispersant
The single largest use for Lignin sulfonates is as plasticizers in making concrete, where they allow concrete to be made with less water (giving stronger concrete) while maintaining the ability of the concrete to flow.
Lignin sulfonates are also used during the production of cement, where they act as grinding aids in the cement mill and as a rawmix slurry deflocculant (that reduces the viscosity of the slurry).
Lignin sulfonates are also used for the production of plasterboard to reduce the amount of water required to make the stucco flow and form the layer between two sheets of paper.
The reduction in water content allows lower kiln temperatures to dry the plasterboard, saving energy.
The ability of Lignin sulfonates to reduce the viscosity of mineral slurries is used to advantage in oil drilling mud, where it replaced tannic acids from quebracho (a tropical tree).
Also one of the very wide uses of Lignin sulfonates is deflocculation of clays used in drilling fluids in the oil and gas industry.
Furthermore, lignosulphates are being researched for use in enhanced oil recovery (EOR) due to their ability to reduce IFT in foams, allowing for improved sweep efficiency, and hence increased recovery factor.
Binder
Besides their use as dispersants Lignin sulfonates are also good binders.
They are used as binders in well-paper, particle boards, linoleum flooring, coal briquettes, and roads.
They also form a constituent of the paste used to coat the lead-antimony-calcium or lead-antimony-selenium grids in a Lead-acid battery.
Aqueous Lignin sulfonate solutions are also widely used as a non-toxic dust suppression agent for unpaved road surfaces, where it is popularly, if erroneously, called "tree sap".
Roads treated with Lignin sulfonates can be distinguished from those treated with calcium chloride by color:
Lignin sulfonates give the road surface a dark grey color, while calcium chloride lend the road surface a distinctive tan or brown color.
As Lignin sulfonates do not rely on water to provide their binding properties, they tend to be more useful in arid locations.
Lignin sulfonateis used as a soil stabilizer
Chemical feedstock
Oxidation of Lignin sulfonates from softwood trees produced vanillin (artificial vanilla flavor).
Dimethyl sulfide and dimethyl sulfoxide (an important organic solvent) are produced from Lignin sulfonates.
The first step involves heating Lignin sulfonates with sulfides or elemental sulfur to produce dimethyl sulfide.
The methyl groups come from methyl ethers present in the lignin.
Oxidation of dimethyl sulfide with nitrogen dioxide produces dimethyl sulfoxide (DMSO).
Other uses
The anti-oxidant effect of Lignin sulfonates is utilized in feeds, ensilage and flame retardants.
The UV absorbance of Lignin sulfonates is utilized in sun screens and bio-pesticides.
Lignin sulfonate are used in agriculture as an analogue of humic substances.
As a soil conditioner, it is mainly used to enhance the absorption and retention of fertilizers and other nutrients.
Lignin sulfonateis able to chelate minerals while remaining bio-degradable, an improvement compared to EDTA.
Further hydrolysis and oxidation produces a product even more similar to humus, marketed as "lignohumate".
Lignin sulfonate s, also referred to as lignosulfonates or lignin sulphonic salts, are by-products of paper production. Wood, the base material from which most paper is made, is primarily composed of two types of materials: carbohydrates (such as cellulose and hemicellulose) and lignins.
Lignins are molecularly complex and diverse, and difficult to break down.
They are undesirable within most paper, so the lignin is extracted by cooking the woody material under pressure with sulphite chemicals.
This process produces a liquor containing sulfonated lignin called lignosulfonate.
The liquor is purified through fermentation, which produces alcohol that is removed.
During these processes, the chemicals that are used can create various lignin sulphonic salts, such as sodium lignosulfonate, calcium lignosulfonate or magnesium lignosulfonate.
The Permitted Substances List (PSL) includes “Lignin and lignin sulfonates (ligno-sulfonates)” on Table 4.2 (columns 1 and 2) – Substances used for crop production, with the annotation:
Permitted as chelating agent(s), as formulant ingredient(s) and as dust suppressant(s).
Ammonium lignosulfonate is prohibited.
Other lignin forms such as lignosulphonic acid, calcium lignosulfonate, magnesium lignosulfonate, sodium lignin and sodium lignosulfonate are permitted.
While lignin sulfonates are identified as permitted substances, there are still questions regarding the forms that are allowed and how they are manufactured.
Lignin sulfonate is restricted to use as a chelating agent, formulant ingredient or dust suppressant under the COR standards.
Chelated micronutrients are widely used to meet nutrient deficiencies in crop production.
Formulants may be used in conjunction with other substances found on the Permitted Substances Lists, and are commonly used in pesticides or fertilizers as inert materials.
Dust suppressants are widely used across agriculture, fertilizer manufacturing and erosion control.
Lignin sulfonate also has a large variety of uses outside the organic industry, including uses in the manufacture of concrete, plasterboard and tanning leather, as a deflocculating agent in linoleum flooring and coal briquettes, and as a fire retardant.
Worldwide, the single largest use of Lignin sulfonates is as water reducers for concrete.
Additional large-volume uses of Lignin sulfonates include animal feed pellet binders, dispersants for gypsum board manufacture, thinners/fluid loss control agents for drilling muds, dispersants/grinding aids for cement manufacture, binders for granulated fertilizers and in dust control applications, particularly road dust abatement, and other specialty dust control applications.
Industry Uses
Adhesives and sealant chemicals
Consumer Uses
Adhesives and sealants
Methods of Manufacturing
Ligninsulfonic acids are made from native lignin.
Two different starting materials are available:
(1) lignin made from sulfite pulping and
(2) lignin made from alkaline (kraft) pulping of wood. In the first case, the sulfite waste liquor is purified and marketed as a liquid or a solid.
Lignin from kraft pulping is first purified and then sulfonated.
Various methods have been developed for isolating and purifying Lignin sulfonates from spent pulping liquors.
One of the earliest and most widely used industrial processes is the Howard process, where calcium Lignin sulfonates are precipitated from spent pulping liquor by addition of excess lime.
Lignin recoveries of 90-95% are obtainable through this process.
Other methods used industrially include ultrafiltration and ion-exclusion, which uses ion-exchange resins to separate lignin from sugars.
Laboratory methods for isolating Lignin sulfonates include dialysis, electrodialysis, ion exclusion, precipitation in alcohol, and extraction with amines.
They can also be isolated by precipitation with long-chain-substituted quaternary ammonium salts.
Industrial ligninsulfonates are globular colloids with molecular masses between 2000 and 100,000 whose structures have not yet been fully elucidated. Their basic structural unit is phenylpropane.
The structural formula shows five structural units linked with the parent unit in various ways.
The degree of sulfonation varies between 0.3 and 1.0 sulfite groups per phenylpropane unit.
IDENTIFICATION AND USE:
Lignosulfuric acid is a by-product of the pulp and paper industry.
Worldwide, the single largest use of Lignin sulfonates is as water reducers for concrete.
Additional large-volume uses of Lignin sulfonates include animal feed pellet binders, dispersants for gypsum board manufacture, thinners/fluid loss control agents for drilling muds, dispersants/grinding aids for cement manufacture, binders for granulated fertilizers and in dust control applications, particularly road dust abatement, and other specialty dust control applications.
Lignosulfuric acid was extensively studied for its anti-HIV and anti-HSV activity in various cellular assays and demonstrated broad anti-HIV and anti-HSV activity.
Lignin sulfonate has long been recognized as an effective dust control agent for unpaved roads.
Lignin is a co-product of the paper industry and is the “glue” that holds cellulose fibers together in trees.
Lignin is extracted from wood during the pulping process, which makes lignin soluble in water.
The adhesive properties of lignin make it an effective dust control solution.
Lignin sulfonate is considered non-toxic when properly applied, making it safe for wildlife, foliage and waterways surrounding road.
Lignin sulfonate treatment eliminates the sliding hazards of loose dirt and gravel by binding it to a hard, skid-resistant surface.
Lignin sulfonate is also considered non-corrosive and can be applied without special safety equipment or clothing.
Vehicles can safely travel over roads treated with Lignin sulfonates almost immediately, eliminating road closures.
When properly applied, lignin sulfonate creates a hardened road surface, is less likely to suffer “washboarding,” and reduces frost heaves common with untreated gravel or dirt roads.
As a result, frequent grading and maintenance can be reduced.
Our commercial Lignin sulfonate product meets the specifications of the U.S. Forest Service Administration, General Service Administration, and local and regional government standards.
Lignin sulfonate use on roads has been endorsed by various agencies for decades.
Lignin sulfonate is a brown powder consisting of a sulfonate salt made from waste liquor of the sulfate pulping process of soft wood: used in concrete, leather tanning, as an additive in oil-well drilling mud, and as a source of vanillin.
Dispersing
Lignin sulfonate is a high weight electrolyte containing sulfonate, carboxyl and phenol hydroxyl groups.
Lignin sulfonate is absorbent to organic and inorganic particles chemically or physically, and keeps them dispersing stably due to its strong hydrophilic property and negative charges.
Binding
Lignin sulfonate has a binding property since it is a high polymer.
Lingin sulfonate has an excellent binding property since it contains not only Lignin sulfonate but also reduces sugar and sugar sulfonate.
Chelating
Lignin sulfonate and sugar derivatives have a chelating property making hydrophilic or hydrophobic compounds since they contain sulfonate, carboxyl and phenol or alcohol hydroxyl groups and they are absorbent to polyvalent metal ions.
Lignins have a long history of use on roads as a method for dust control and surface stabilization.
Lignin road products are derived from the lignin that naturally binds cellulose fibers together to give trees and plants firmness.
These products are a safe and economical alternative to petroleum and salt-based products that are also sometimes applied to road surfaces.
The original method of applying Lignins to road surfaces for dust control was very simple: dilute raw Lignin solutions were sprayed in light applications onto dirt roads.
Over time, road surfaces began to show an improved stabilization, increasing the appeal of using Lignins.
Lignin is well suited for a variety of uses such as parking lots, driveways, and road shoulders, where pavement is too costly and dust conditions become intolerable.
Lignin sulfonates are used on unpaved roads to reduce environmental concerns from airborned dust particles and to stabilize the road surface.
Lignin Sulfonate does not have any negative impacts on our environment and/or human health.
Lignin sulfonate contains no constituents that are considered hazardous by any Government agency.
Further, it’s health rating is 0, which simply means exposure offers little or no risk to either plants or humans.
Lignin simply contains no oil based contaminants.
Like magnesium chloride it is soluble in water.
Further, lignin is biodegradable.
Primary dispersing agent for dyestuffs and agricultural chemicals.
A sulfonate salt of lignin that is produced as a waste product from chemical processes for making paper pulp.
Lignin sulfonate is a brown powder that forms a colloidal solution in water.
Lignin sulfonate is used as a dispersant for concrete and for carbon black additions to rubber.
Lignin sulfonate is also used as a tanning agent for leather.
IUPAC NAMES:
3-(2-hydroxy-3-methoxyphenyl)-2-[2-methoxy-4-(3-sulfopropyl)phenoxy]propane-1-sulfonic acid
Lignosulfonic acid
SYNONYMS:
LIGNOSULFONIC ACID
8062-15-5
3-(2-hydroxy-3-methoxyphenyl)-2-[2-methoxy-4-(3-sulfopropyl)phenoxy]propane-1-sulfonic acid
CALCIUM-LIGNIN SULFONATE
SCHEMBL21563979
3-(2-Hydroxy-3-methoxyphenyl)-2-[2-methoxy-4-(3-sulfopropyl)phenoxy]-1-propanesulfonic acid
Lignosulfate
Lignin sulfonate
Lignosulfonic acid
lignosulfuric acid
LIGNOsulfonate
LIGNINsulfonate
LIGNOSULPHONICACID
Lignin sulfonate (aqueous)
Ligninsulfonic acid
Aids000665
Aids-000665
Ameribond 2x
Indulin sn
Ls
Lst 7
Poly(lignosulfonic acid)
TIANFU-CHEM CAS NO.8062-15-5
