What is the best paper in polymer

The natural polymers include polysaccharides, proteins, lignin, natural rubber and asphalt. The raw materials from plants and animals differ fundamentally in their chemical structure. The vegetable raw materials provide polymers made from polysaccharides. The sugar molecules are linked to form long, chain-like connections. They include starch and cellulose. The animal raw materials provide proteins. They combine amino acids to form spirally rolled up chains. Silk and wool therefore differ fundamentally in the chemical structure of cotton and linen.



a) Vegetable raw materials based on cellulose

Cellulose
 
Cellulose is the most abundant natural polymer found in nature and also the most abundant organic compound. Cellulose, together with lignin and pectins, form the structural substance for plant cell walls. With the exception of a few tunicates, cellulose cannot be found in animals. The macromolecule of cellulose is made up of the double sugar cellobiose. A cellobiose molecule contains two basic units of glucose, which are linked together by a β link. Cellulose polymers contain up to 5000 glucose units. The hydrogen bonds between the macromolecules prevent the molecule from spiraling. In contrast to starch, the macromolecule of cellulose is therefore arranged linearly.


   
Cellulose molecule with β-linkages and hydrogen bonds between the polymers
 

The enzymes of many organisms cannot digest the cellulose. The exceptions are wood-destroying fungi and herbivores. Microorganisms that can break down the cellulose molecule into individual glucose units live in the stomachs of cattle. Boiling cellulose in strong acids converts the polymer almost entirely into glucose. Acid droplets therefore make cotton fabrics brittle. Cellulose is a universal raw material for the paper and textile industry. In addition, it is the starting material for the production of numerous plastics and cellulose compounds. Cellulose is insoluble in water and most organic solvents and can therefore be easily separated from the other components of the plant.
 
 
Wood

Wood is the most important raw material for paper. It contains up to 50 percent cellulose fibers. The fibers are firmly connected to the aromatic lignin, which results in a high level of stability. Lignin is also a natural polymer. It makes up 25 percent of the wood, while the remaining components are made up of aromatic oils, resins and hemicelluloses. Wood is an important raw material for cellulose products such as paper and certain plastics. By heating in the absence of air, charcoal is obtained in a coking that can be used for heating. Wood is also used to produce synthesis gas; the secondary ingredients such as rubber, resins or oils are used to produce secondary products such as rubber, paints, adhesives and fragrances.
 

 

Pulp and wood pulp

From wood and the straw of cellulose-containing plants can cellulose win. During cellulose production, all other components of the plant, such as lignin, are separated from the cellulose in a chemical process. in the Kraft method the separation takes place by boiling the wood chips in an alkaline sulfur salt solution. A brown cellulose material is obtained which is suitable for the production of wrapping paper. Subsequent bleaching with chlorine or oxygen is necessary to remove the brown color. At the Sulphite process the lignin is boiled in an acidic sulfuric salt solution and separated. The pulp obtained from the sulphite process is lighter and softer, but not as firm. In both of these processes, only half of the wood is processed. The other half is burned and used to generate energy.
 
In the past, the pulp used to make paper was produced mechanically. Wooden sticks were frayed by a large rotating grindstone with the addition of water in order to tear the wood fibers out of the wood. This procedure is called Wood pulp. In modern mechanical processes, for example the CTMP process, the wood is pretreated with steam and chemicals. However, this method is associated with a considerable consumption of energy and the resulting Wood pulp is too coarse for fine paper types. It is suitable for cheap types of paper such as newsprint.
 
All three processes lead to considerable environmental pollution. The Kraft and sulfite processes release toxic gases such as sulfur dioxide and hydrogen sulfide, which is why an exhaust air system is necessary. If the washed-out wood residues are given into the water, the fibers there use up oxygen and lead to the water tipping over. Newer processes for cellulose production such as the Allcell process or the Organocell process remove the accompanying wood pulp from the wood with the help of organic solvents at increased temperature and pressure. The development and use of these technologies contribute significantly to reducing the environmental impact.


paper
 
After the fibers have been isolated from the wood, they are felted into a solid structure. First of all, the pulp delivered is prepared into a suspension with water. Natural minerals are added to the suspension as fillers. These save pulp and give the paper better properties, making it whiter and more opaque. The addition of adhesives such as resins or alum make the paper water-repellent and prevent the ink from flowing out. Dyes give the paper the desired color. Then the fiber mixture, the pulp, reaches a smooth sieve, where it is evenly distributed, rolled or pressed and dried.
 
 
cotton
 
Cotton is a natural vegetable fiber that comes from the seed hairs of the cotton bush, which belongs to the mallow family Gossypium is won. After the shrub has bloomed, a fruit capsule develops from which a wad of white seed hair protrudes. The length of the hair varies from one to six centimeters. The largest cotton fields can be found in the southwestern United States. After the seed hairs have been collected and cleaned, a yarn can be produced by spinning, which is used in the manufacture of numerous products in the textile industry. Cotton can be bleached and dyed (e.g. with the vat dye indigo) and is also suitable for making wadding.
 



Flax, linen
 
Flax is a natural textile fiber that is obtained from the blue flowering flax fiber. The somewhat smaller and more branched oil flax is used to produce flax oil. The flax plant is one of the oldest known cultivated plants. Even the ancient Egyptians wove flax sheets, some of which are still preserved on the mummies today. When harvesting, the whole flax plant is torn up and piled up to dry. After being laid out on the ground for a long time, known as "roasting", the stalks are dried and broken. Then you pull the fibers over a board studded with nails to align them parallel. The long fibers obtained can be used to spin yarns from which linen is woven. They are also suitable for making twine or laces.
 



hemp
 
Hemp is an annual plant up to three meters high Cannabis sativa , from which strong and elastic fibers can be obtained. The stems of the hemp are hollow on the inside and lined with a fibrous bark. The hemp fiber, which consists of cellulose, can be up to 55 centimeters long, making it the longest useful vegetable fiber. The fiber is used to produce particularly stable material, for example for canvas, ropes and packing cords. Recently, eco-textiles have also been made from hemp. The resin secreted from the female inflorescences and also the hemp seeds are called hashish smoked. marijuana refers to a mixture of the leaves, shoots and inflorescences of the upper part of the female plant.
 

 

b) Products made from vegetable raw materials on a cellulose basis

Viscose fibers
 
Strictly speaking, the viscose fiber is not a natural fiber. Although it is obtained from the natural raw material wood pulp, the fiber is produced chemically. The pulp delivered by the pulp mills is first mixed with concentrated caustic soda. This causes the cellulose to swell. The polymers are broken down into shorter chains. By adding carbon disulfide, cellulose xanthate, an orange-yellow, viscous mass, which is also known as viscose referred to as. After adding dilute sodium hydroxide solution, a solution is obtained which is pressed into an acid bath through spinnerets. The viscose disintegrates and is obtained regenerated cellulose in the form of fine threads. This process produces extremely toxic decomposition products such as hydrogen sulfide and carbon disulfide, which are easily flammable and form explosive mixtures with the air. Viscose fibers have a silk-like sheen. They are processed into yarns and used in a variety of ways in the textile and furniture industries. Regenerated cellulose in film form can also be obtained from the viscose solution. This is in the trade under the name cellophane known.
 
 
Cellulose acetate (CA)
 
Cellulose acetate is an ester of cellulose that was discovered in 1865. But it wasn't until 1904 that a product was developed from which foils and films could be made. During production, the OH groups of the cellulose are esterified with acetic anhydride with the addition of sulfuric acid to form cellulose triacetate. By heating and adding water, a small proportion of the acetate groups are split off again and acetyl cellulose is obtained, which has shorter chains in the molecular structure. Acetyl cellulose is soluble in acetone and can be made from it Acetate fibers be crazy. These fibers were formerly called Rayon designated. However, the term is no longer common today because it actually has nothing to do with silk. In combination with plasticizers, a thermoplastic material is obtained that is used to manufacture handles on tools, keyboards, steering wheels and ballpoint pens.
 




Celluloid, cell horn
 
Around 1900, 12,000 elephants were killed annually to extract ivory from their tusks. Ivory was mainly used for billiard balls and piano keyboards. Small bumps in the billiard balls so annoyed an American billiard player around 1870 that he offered a $ 10,000 reward for making a better material. Around the same time, the Hyatt brothers succeeded in making a new material from cotton. By treating cotton with concentrated nitric acid and concentrated sulfuric acid (nitrating acid), gun cotton (an> ester of cellulose) is obtained. This is suitable as an explosive and, in a weakened form, as gunpowder. By dissolving the gun cotton in a mixture of alcohol and camphor, the Hyatt brothers obtained a material that was as transparent as glass and tougher than leather.
 



The celluloid obtained could be dyed and it melted at low temperatures without flowing. Celluloid was the first industrially produced thermoplastic material. The properties of celluloid also enabled the Hyatt brothers to design the first injection molding machine. The high toughness and transparency of the celluloid made it possible to use it as a carrier material for films in photography and in the cinema. Due to its high flammability, it was later replaced by other plastics. Today the celluloid is still used to make table tennis balls, buttons, combs and glasses frames.
 
 
c) Protein-based animal raw materials

Some animal raw materials are used as polymers themselves or to make polymers. Casein formaldehyde is produced by hardening natural proteins from milk or eggs with formaldehyde. The natural fibers wool and silk also contain protein-based polymers.

Wool
 
Sheep wool can be obtained from the animal hair of the domestic sheep. The sheep are sheared once a year to produce wool. In a broader sense, wool also includes other animal textile fibers, for example the lower hairs of the South American lamas (llama wool, alpaca wool), rabbits (angora wool) or goats (cashmere wool, mohair wool). Wool essentially consists of keratins, which are part of the fiber proteins. In wool, the protein molecules are rolled up in a spiral, which explains the elasticity of the fiber.
 
Three to five kilograms of wool can be obtained per sheep. When shearing, the sheep's fur is sheared off in one piece and the fleece is obtained. After shearing, the wool is first cleaned of wool sweat, which consists of wool fat and dried sweat, by washing. The sheep secrete the wool fat from their sebum glands, it serves to protect their fur. Wool fat is processed into lanolin and then used as an ointment base in the cosmetics industry. After drying, the sheep's wool is plucked and spun into a wool thread.
  
 

When moving strongly in boiling water, the wool fibers become matted. Wool can be grown by walking in the water felt to process. Felt is a relatively strong material that is used to make clothes, shoes or carpet underlay. Wool is acid-resistant, but it is attacked by diluted lye, as the polypeptide bonds are broken. Wool fibers can be dyed well with stain dyes.
 
 
silk
 
The manufacturing process for silk was discovered in China more than 5000 years ago. The Romans brought the valuable material to Europe via the famous, 10,000-kilometer-long Silk Road. The silk fiber is made from the cocoons of the silk moth Bombyx mori won. The caterpillars of the butterfly create the cocoon with the help of their spinning glands in order to pupate into a finished butterfly. The silk threads of the caterpillars contain the fiber protein fibroin, which is surrounded by a water-soluble bast substance sericin as a support. The chemical structure of the long-chain protein molecule with its peptide bonds is very similar to that of artificial polyamides. A single silk thread from a caterpillar can be up to four kilometers long!

    

The cocoons are harvested together with the caterpillar and placed in a container with hot soapy water. The caterpillars die off and the bast substance dissolves in the water. From 50,000 caterpillars you get about 120 kilograms of silk, per caterpillar about two grams. By unwinding the cocoons you get threads that are twisted into a silk thread. Silk feels soft and supple, it has a high sheen, good thermal insulation with low weight and does not crease. It is processed into ties, scarves, dresses, pillows or bed linen.
 
 
leather
 
Leather is the term used to describe animal skin that has been freed from hair or feathers, for example from cattle, calves, pigs or goats. If the hair is still there, it is one fur. The skins are made up of collagens, which belong to the fiber proteins. By the Tanning the skins are made usable and durable. Tannery is one of the oldest trades known to man. Today there is a multitude of procedures for the different animal skins, the process is extremely complicated and lengthy.
 

 

The skin of mammals is divided into epidermis, dermis and subcutaneous tissue. In most cases, only the dermis is required for leather production; it contains the stable connective tissue and muscles. Before tanning, the dermis is freed from the epidermis and hair using chemical processes. A mixture of sodium sulfide and milk of lime softens the epidermis so that it can be peeled off easily. The actual tanning is done either with vegetable substances or with mineral salts. Tanning with alum or chromium salts shrinks the leather and provides a durable and elastic leather for clothing, shoes and bags. When tanning with vegetable substances, tannic acid is used, which is obtained from wood or vegetable galls. Leathers tanned with tannin are particularly waterproof and suitable for shoe soles or upholstery.
 
 
gelatin
 
Gelatine is a polypeptide that is obtained primarily from slaughterhouse waste such as skin and bones. It contains a high proportion of collagen, a fiber protein found in connective tissues. Except for tryptophan, it contains all essential amino acids and is therefore suitable as an easily digestible food component. It is commercially available as a powder or in thin sheets. Gelatine swells in warm water and solidifies to form a gelatinous solution. Gelatine is used to make jellies such as jelly or puddings, aspic, ice cream and yoghurt. In the pharmaceutical industry, it is used as a binding agent for tablets and for the manufacture of capsules. In cosmetics, it is a widely used ingredient in ointments and creams.
 
Since the bovine epidemic BSE occurred, consumers have become more and more insecure.According to the manufacturer, the active proteins necessary for disease transmission are destroyed during gelatine processing, even if a sick cattle is processed due to a lack of control. As long as the transmission routes for diseases such as Kreutzfeld-Jakob have not yet been clearly clarified, an uncertainty factor remains.