1. Wood Chemistry PSE 406
Uses of Wood Chemicals

2. Agenda Modifications and uses of: Cellulose Hemicelluloses Lignin
Extractives

3. Chemical Uses of Cellulose
As a product, most cellulose is found in pulp products (300 million tons/yr pulp).
A small amount (<1% of pulp) of cellulose is isolated and sold as a chemical product; a polymeric material.
Cellulose must be free of lignin and hemicelluloses; this is dissolving pulp mainly produced through acid sulfite pulping.
The pulping and bleaching processes are hard on cellulose reducing molecular weight significantly.
As a chemical product, cellulose is sold as cellulose derivatives.

4. Cellulose Nitrate Uses: Inorganic esters Ping pong balls Membranes
HONO2+2H2SO NO2+ + H3O+ + 2HSO4‾
NO2+ + HO-Cell NO2-OH-Cell NO2-O-Cell +H+
Uses:
Ping pong balls
Membranes
Fingernail polish
Records (LP)
Cellulose Acetate (Bexoid, Clarifoil, Tenite)
Cellulose nitrate had one severe drawback — its flammability This had prevented its use in mass production, rapid moulding techniques. Cellulose acetate, developed around the turn of the century met this problem. Among its early uses were as ‘safety’ film and dope to stiffen and waterproof the fabric wings and fuselage of early aeroplanes. It was initially fabricated like celluloid in the form of rod, sheet or tube but later became available as a moulding powder in various degrees of hardness which could be quickly and economically shaped by injection moulding. As such it did much to encourage the development of injection moulding machinery — one of the key processes in plastics fabrication.
Cellulose nitrate, known by most people as ‘celluloid’, was the first plastics to achieve real success — but only after many false starts and financial failures. Credit for the invention goes to the British inventor, Alexander Parkes (photo), who displayed his material (which he called Parkesine) at the Great International Exhibition in London, Among other things, he saw his material as a substitute for the increasingly scarce materials ivory and tortoiseshell and his display of brooches, decorative trinkets and knife handles were to win for Parkes an ‘award for excellence’.
To exploit his invention he formed in 1866 the Parkesine Company but this was soon to go into liquidation as he attempted to cut quality in his drive for lower costs. It was to be a decade or so later, under the direction of the Merriam family and their British Xylonite Company Limited, that the material (by then renamed Xylonite) began to achieve commercial success with products such as combs, collars and cuffs. Most of the credit for commercial success and technical excellence, however, goes to the Hyatt brothers in America with their material, which they called ‘celluloid’. Through the unlikely work to develop a substitute for the ivory, billiard ball they devised a process for manufacturers using a cellulose nitrate composition. In their patent of 1870 they described the all-important discovery —the solvent action of camphor on cellulose nitrate. Among their earliest commercial successes was dental plates for false teeth.

5. Cellulose Acetate Organic ester Uses: Textile fiber
Plastics (acetates)-used to make photographic films
Components in some adhesives
Cigarette filters
High absorbency products: diapers, surgical products, and other filters
Toys: the original Lego bricks, made from 1949 to 1957
Cellulose acetate, first prepared in 1865, is the acetate ester of cellulose. Cellulose acetate is used as a film base in photography, and as a component in some adhesives; it is also used as a synthetic fiber.
Cellulose acetate (triacetate) photographic film was introduced in 1934 as a replacement for the unstable and highly flammable cellulose nitrate film stock that had previously been standard. Acetate photographic film deteriorates in the presence of oxygen to an unusable state, releasing acetic acid. This is known as "vinegar syndrome." Acetate film stock is still used in some applications, such as camera negative for motion pictures. Since the 1980s polyester film stock (sometimes referred to under Kodak's trade name "Estar") has become more commonplace, particularly for archival applications. Acetate film was also used as the base for magnetic tape prior to the advent of polyester film.

6. Cellulose Organic Ethers
Carboxymethyl cellulose (CMC), alkyl cellulose (methyl, ethyl).
Mostly used as thickening agents.
Used to thicken cheap ice cream products without having to add cream.
The polar (organic acid) carboxyl groups render the cellulose soluble and chemically reactive.
CMC dissolves rapidly in cold water and mainly used for controlling viscosity without gelling (CMC, at typical concentrations, does not gel even in the presence of calcium ions). As its viscosity drops during heating, it may be used to improve the volume yield during baking by encouraging gas bubble formation. Its control of viscosity allows use as thickener, phase and emulsion stabilizer (e.g. with milk casein), and suspending agent. CMC can be also used for its water-holding capacity as this is high even at low viscosity; particularly when used as the Ca2+ salt. Thus, it is used for retarding staling and reducing fat uptake into fried foods.
CMC is used in food science as a viscosity modifier or thickener, and to stabilize emulsions, for instance in ice cream. It has E number E466. It is also a constituent of many non-food products, such as K-Y Jelly, toothpaste, laxatives, diet pills, water-based paints, detergents, and various paper products. They have high viscosity, are not toxic, and are generally non-allergenic. CMC is used as a lubricant in non-volatile eye drops (artificial tears). Sometimes it is methylcellulose (MC) which is used, but its non-polar methyl groups (-CH3) do not add any solubility or chemical reactivity to the base cellulose.

7. Rayon Pure regenerated cellulose.
Rayon is manufacture from cellulose xanthate (adding of carbon disulfide in a process known as Xanthation).
Uses:
Fabrics: blouses, dresses, jackets, linings, suits
Furnishings: bedspreads, blankets, slipcovers)
Industrial: medical surgery products, tire cords)
Carbon disulfate+Alkali+cellulose=rayon
Rayon is produced from naturally occurring polymers and therefore it is not a synthetic fiber, but a manufactured regenerated cellulosic fiber. The fiber was sold as artificial silk until the name "rayon" was adopted in In Europe it is known as "viscose" which has been ruled an acceptable alternative term for rayon in the US by the Federal Trade Commission. Rayon was only produced as a filament fiber until the 1930s when it was discovered that broken waste rayon could be used in staple fiber. The physical properties of rayon were unchanged until the development of high-tenacity rayon in the 1940s. Further research and development led to the creation of high-wet-modulus rayon (HWM rayon) in the 1950s [1]
Rayon is a very versatile fiber and has the same comfort properties as other natural fibers and can imitate the feel and texture of silk, wool, cotton and linen. The fibers are easily dyed in a wide range of colors. Rayon fabrics are soft, smooth, cool, comfortable, and highly absorbent, but they do not insulate body heat making them ideal for use in hot and humid climates [2]. The durability and appearance retention of regular rayon are low, especially when wet; also rayon has the lowest elastic recovery of any fiber. However, HWM rayon is much stronger and exhibits higher durability and appearance retention. Recommended care for regular rayon is dry-cleaning only, HWM Rayon can also be machine washed [1]. Regular rayon (or viscose) is the most widely produced form of rayon. This method of rayon production has been utilized since the early 1900s and it has the ability to produce either filament or staple fibers. The process is as follows:
CELLULOSE: Production begins with processed cellulose
IMMERSION: The cellulose is dissolved in caustic soda
PRESSING: The solution is then pressed between rollers to remove excess liquid
WHITE CRUMB: The pressed sheets are crumbled or shredded to produce what is known as "white crumb"
AGING: The "white crumb" aged through exposure to oxygen
XANTHATION: The aged "white crumb" is mixed with carbon disulfide in a process known as Xanthation
YELLOW CRUMB: Xanthation changes the chemical makeup of the cellulose mixture and the resulting product is now called "yellow crumb"
VISCOSE: The "yellow crumb" is dissolved in a caustic solution to form viscose
RIPENING: The viscose is set to stand for a period of time, allowing it to ripen
FILTERING: After ripening, the viscose is filtered to remove any undissolved particles
DEGASSING: Any bubbles of air are pressed from the viscose in a degassing process
EXTRUDING: The viscose solution is extruded through a spinneret, which resembles a shower head with many small holes
ACID BATH: As the viscose exits the spinneret, it lands in a bath of sulfuric acid resulting in the formation of rayon filaments
DRAWING: The rayon filaments are stretched, known as drawing, to straighten out the fibers
WASHING: The fibers are then washed to remove any residual chemicals
CUTTING: If filament fibers are desired the process ends here. The filaments are cut down when producing staple fibers [3].
High Wet Modulus rayon (HWM) is a modified version of viscose that has a greater strength when wet. It also has the ability to be mercerized like cotton. HWM rayons are also known as "polynosic" or can

8. Hemicelluloses
During Kraft pulping, hemicelluloses mainly oxidized to low MW carboxylic acids.
In acid sulfite pulping, hemicelluloses are cleaved to individual sugars.
Fermentation of 6 carbon sugars to alcohol.
Requires liquor from softwood cook.
Alcohol can be used as
gasoline additive
solvents
in the manufacture of white vinegar.
Five carbon sugars are isolated from hardwood liquors through chromatography for conversion to xylitol (sweetener).
Xylitol causes bacteria to lose the ability to adhere to the tooth, stunting the cavity causing process.
Xylitol, gram for gram, is roughly as sweet as sucrose, but contains 40% less food energy. Its formula is C5H12O5, with relative mass amu. The molecule's systematic name is (2,3,4,5)tetrahydroxy-pentanol, and in IUPAC name pentane-1,2,3,4,5-pentaol. CAS number for Xylitol is It is very popular in Finland, which is considered its "home country". Many Finnish confectioneries employ xylitol, or have a xylitol version available. Virtually all chewing gum sold in Finland and Europe is sweetened with xylitol. The Spanish company Chupa Chups makes a xylitol-based breath mint, Smint, that it markets worldwide. In China, Japan and South Korea, xylitol is found in wide assortment of chewing gums. In 2004, popular North American Trident gum was reformulated to include xylitol, but not as the main sweetener (which is still sorbitol). Also sold in North America is Carefree Koolerz, which is a sugarless gum sweetened exclusively with xylitol.
Xylitol is a naturally occurring sweetener found in the fibers of many fruits and vegetables including, various berries, corn husks, oats and mushrooms.[1]
Dental care
Xylitol is a "Toothfriendly" sugar substitute. In addition to not encouraging tooth decay (by replacing dietary sugars), xylitol may actively aid in repairing minor cavities caused by dental caries. Recent research[2] confirms a plaque-reducing effect and suggests that the compound, having some chemical properties similar to sucrose, attracts and then "starves" harmful micro-organisms, allowing the mouth to remineralize damaged teeth with less interruption. (However, this same effect also interferes with yeast micro-organisms and others, so xylitol is inappropriate for making bread, for instance.) Dental pioneers such as Dr. Ellie Phillips have championed the use of xylitol as a preventive dental treatment, although most traditional dentists in the United States are still hesitant to recommend it to their patients, or are ignorant of the proven beneifits.
[edit] Diabetes
Possessing approximately 40% less food energy,[3] xylitol is a low-calorie alternative to table sugar. Absorbed more slowly than sugar, it doesn't contribute to high blood sugar levels or the resulting hyperglycemia caused by insufficient insulin response.
[edit] Osteoporosis
Xylitol also appears to have potential as a treatment for osteoporosis. A group of Finnish researchers have found that dietary xylitol prevents weakening of bones in laboratory rats, and actually improves bone density.[4][5]
[edit] Ear and upper respiratory infections

9. The Sad Reality of Lignin
The total amount of lignin processed each year is roughly (very) 100 million tons.
Approximately 1 million tons/year sold globally.
Most as lignosulfonates from acid sulfite pulping.
A small amount is from the kraft process.
The sad reality of lignin is that almost all of the lignin isolated in pulping operations is burned.

10. Lignosulfonates
Lignosulfonates is the name for a product containing sulfonated lignin and other wood chemicals.
Mainly from the acid sulfite process.
A small amount from sulfonated kraft lignin.
Before becoming lignosulfonates (marketable product), this material (spent sulfite liquor) is “cleaned up”.
Pulping chemicals are removed.
Sometimes non lignin compounds (sugars, etc) are removed chemically, biologically, or through physical methods.
Often the lignin is chemically modified.
Product is concentrated to a molasses thickness product or to a powder.

11. Lignin Uses Dispersant Binder
Concrete, Dyes, Gypsum wallboard
Binder
Road dust control, animal feed
Emulsifier (think an oil and vinegar salad dressing)
Chelating agent
Oil Well Drilling Fluids, Micronutrient Fertilizers
Raw material for chemical production
Vanillin (softwood)
Researcher Stig Are Gundersen in the research department in Sarpsborg has been leading the work of assessing which lignin products could be more widely used in emulsions. ”Emulsions are finely dispersed drops of oil or wax in water. Milk and butter are well known emulsions. To make an emulsion, drops of oil or wax must be finely dispersed in water, which uses a lot of energy. Once the emulsion has been created, it is important that it should be stable, so that the constituents do not separate out again. It is the job of the lignin to keep the drops fluid and prevent them clumping together and forming layers,” explains Gundersen.
There are a number of different emulsifiers on the market. The problem with many of them is that they have other, undesirable properties that can affect the product. The lignin products act as stabilisers in the emulsions, which does mean that more energy is needed to create the emulsion. On the other hand, lignin has fewer side effects and undesirable properties and is a good stabiliser, which means the emulsion is more stable and can stand greater stress. Borregaard LignoTech is concentrating on wax emulsions and emulsions with solvents.

12. Concrete Dispersant
Concrete is made up of 3 ingredients: cement, sand, and aggregate.
Water is mixed in to make a workable slurry and to harden the concrete.
By using a dispersant like lignosulfonates, less water can be used to get the same viscosity slurry. This makes stronger concrete.
Lignin as an Emulsifier
Lignosulfonate stabilizes emulsions of immiscible liquids, such as oil and water, making them highly resistant to breaking. Lignosulfonates are at work as emulsifiers in:
asphalt emulsions pesticides pigments & dyes wax emulsions
Image borrowed from JimRadfprd.com

13. Dye Dispersant Dyes used to dye cloth are water insoluble.
In order to dye cloth, dye particles are dispersed in water. What this means are the dye particles are small enough that they pretty much act like they are dissolved. A dispersant keep them apart so they don’t get big and sink. Sulfonated lignins do this very well. After dying, the lignin is washed out.
Lignin as a Dispersant
Lignosulfonate prevents the clumping and settling of undissolved particles in suspensions. By attaching to the particle surface, it keeps the particle from being attracted to other particles and reduces the amount of water needed to use the product effectively. The dispersing property makes lignosulfonate useful in:
cement mixes leather tanning clay & ceramics concrete admixtures dyes & pigments gypsum board oil drilling muds pesticides & insecticides

14. Binding-Dust Control
Dusty roads are considered a health hazard by the government and thus dust control is mandated
Dust can be controlled with water, lignosulfonates or calcium chloride.

15. Binding-Dust Control
Lignosulfonates cause the particles to pack closer together and also to adhere.
This process forms a dust “free” and also more stable road.
Lignin as a Binder
Lignosulfonates are a very effective and economical adhesive, acting as a binding agent or "glue" in pellets or compressed materials. Lignosulfonates used on unpaved roads reduce environmental concerns from airborne dust particles and stabilize the road surface. This binding ability makes it a useful component of:
coal briquettes plywood & particle board ceramics animal feed pellets carbon black fiberglass insulation fertilizers & herbicides linoleum paste dust suppressants soil stabilizers

16. Pellet Binder
The natural stickiness of lignosulfonates help them function as a pellet binder; it helps hold the material together.

17. Micronutrient Fertilizer
Plants need trace metals just like people do. Unfortunately, many of these metals are not available to the plant because they are absent or not water soluble.
Lignosulfonates will chelate or hold on to these metals making them available to plants either through soil or foliar applications.
Lignin as a Sequestrant
Lignosulfonates can tie up metal ions, preventing them from reacting with other compounds and becoming insoluble. Metal ions sequestered with lignosulfonates stay dissolved in solution, keeping them available to plants and preventing scaly deposits in water systems. As a result, they are used in:
micronutrient systems cleaning compounds water treatments for boilers and cooling systems

18. Key Points on Lignin Use
I have listed a large number of uses
Even with all these uses the total sales of lignin is only 1-2 % of what is isolated in pulping.
There is no huge volume use for lignin (like gasoline) to drive the market.
Mostly lignin sells because it is cheaper than petroleum based products. There are instances, however, where lignin sells because it is better than the competition.

19. Extractives
We covered extractive use as we went. Here is a list of extractives isolated from the pulp & paper industry for sale.
Turpentine (monoterpenes)
Tall Oil
Rosin (resin acids)
Fatty acids
Sterols (don’t forget Benecol)
Tannins (limited amounts)