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Cellophane
Cellophane is a thin, transparent sheet made of regenerated cellulose. Its low permeability to air, oils, greases, bacteria, and liquid water makes it useful for food packaging. Cellophane is highly permeable to water vapour, but may be coated with nitrocellulose lacquer to prevent this. Cellophane is also used in transparent pressure-sensitive tape, tubing, and many other similar applications. Cellophane is compostable and biodegradable, and can be obtained from biomaterials. The original production process uses carbon disulfide (CS2), which has been found to be highly toxic to workers. The newer lyocell process can be used to produce cellulose film without involving carbon disulfide. "Cellophane" is a generic term in some countries, while in other countries it is a registered trademark owned by DuPont. Production Cellulose is produced from wood, cotton, hemp, and other organic fibres, dissolved in alkali and carbon disulfide to make a solution of liquid viscose. The s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellulose
Cellulose is an organic compound with the chemical formula, formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of glycosidic bond, β(1→4) linked glucose, D-glucose units. Cellulose is an important structural component of the primary cell wall of green plants, many forms of algae and the oomycetes. Some species of bacteria secrete it to form biofilms. Cellulose is the most abundant biopolymer, organic polymer on Earth. The cellulose content of cotton fibre is 90%, that of wood is 40–50%, and that of dried hemp is approximately 57%. Cellulose is mainly used 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 crops into biofuels such as cellulosic ethanol is under development as a renewable fuel source. Cellulose for industrial use is mainly obtained from wood pulp and cotton. Cellulose is also greatly affected by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Disulfide
Carbon disulfide (also spelled as carbon disulphide) is an inorganic compound with the chemical formula and structure . It is also considered as the anhydride of thiocarbonic acid. It is a colorless, flammable, neurotoxic liquid that is used as a building block in organic synthesis. Pure carbon disulfide has a pleasant, ether- or chloroform-like odor, but commercial samples are usually yellowish and are typically contaminated with foul-smelling impurities.. History In 1796, the German chemist Wilhelm August Lampadius (1772–1842) first prepared carbon disulfide by heating pyrite with moist charcoal. He called it "liquid sulfur" (''flüssig Schwefel''). The composition of carbon disulfide was finally determined in 1813 by the team of the Swedish chemist Jöns Jacob Berzelius (1779–1848) and the Swiss-British chemist Alexander Marcet (1770–1822). Their analysis was consistent with an empirical formula of CS2. Occurrence, manufacture, properties Small amounts of carbon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xanthation
A xanthate is a salt or ester of a xanthic acid. The formula of the salt of xanthic acid is (where R is organyl group and M is usually Na or K). Xanthate also refers to the anion . The formula of a xanthic acid is , such as ethyl xanthic acid, while the formula of a xanthate ester is , where R and R' are organyl groups. The salts of xanthates are sometimes called ''O''-organyl dithioates. The esters of xanthic acid are sometimes called ''O'',''S''-diorganyl esters of dithiocarbonic acid. The name ''xanthate'' is derived from Ancient Greek (''xanthos'') meaning 'yellowish' or 'golden', and indeed most xanthate salts are yellow. They were discovered and named in 1823 by Danish chemist William Christopher Zeise. These organosulfur compounds are important in two areas: the production of cellophane and related polymers from cellulose and (in mining) for extraction of certain sulphide bearing ores. They are also versatile intermediates in organic synthesis. Formation and structur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure-sensitive Tape
Pressure-sensitive tape or pressure-sensitive adhesive tape (PSA tape) is an adhesive tape that sticks when pressure is applied without the need for a solvent (such as water) or heat for activation. It is also known in various countries as self-stick tape, sticky tape, or just adhesive tape and tape, as well as genericized trademarks, such as '' Sellotape'', '' Durex (tape)'', '' Scotch tape'', etc. PSA tape consists of three components: *the tape itself, which often is cellophane, cellulose acetate, or polyvinyl chloride. Other materials include paper, plastic film, cloth, or metal foil coated onto a backing material such as paper, plastic film, cloth, or metal foil. *a pressure-sensitive adhesive. *release liner, which keeps the tape from sticking to itself. Some have layers of adhesives, primers, release agents, filaments, printing, etc. made for specific functions. It sticks without the need for a solvent such as water or heat for activation. By contrast, "gummed" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wood
Wood is a structural tissue/material found as xylem in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin that resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or more broadly to include the same type of tissue elsewhere, such as in the roots of trees or shrubs. In a living tree, it performs a mechanical-support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients among the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, woodchips, or fibers. Wood has been used for thousands of years for fuel, as a construction material, for making tools and weapons, furniture and paper. More recently it emerged as a feedstock for the production ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfuric Acid
Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, and hydrogen, with the molecular formula . It is a colorless, odorless, and Viscosity, viscous liquid that is Miscibility, miscible with water. Pure sulfuric acid does not occur naturally due to its Dehydration reaction, strong affinity to water vapor; it is Hygroscopy, hygroscopic and readily absorbs water vapor from the Atmosphere of Earth, air. Concentrated sulfuric acid is a strong oxidant with powerful dehydrating properties, making it highly corrosive towards other materials, from rocks to metals. Phosphorus pentoxide is a notable exception in that it is not dehydrated by sulfuric acid but, to the contrary, dehydrates sulfuric acid to sulfur trioxide. Upon addition of sulfuric acid to water, a considerable amount of heat is releas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur
Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with the chemical formula S8. Elemental sulfur is a bright yellow, crystalline solid at room temperature. Sulfur is the tenth most abundant element by mass in the universe and the fifth most common on Earth. Though sometimes found in pure, native form, sulfur on Earth usually occurs as sulfide and sulfate minerals. Being abundant in native form, sulfur was known in ancient times, being mentioned for its uses in ancient India, ancient Greece, China, and ancient Egypt. Historically and in literature sulfur is also called brimstone, which means "burning stone". Almost all elemental sulfur is produced as a byproduct of removing sulfur-containing contaminants from natural gas and petroleum.. Downloahere Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Registered Trademark
A trademark (also written trade mark or trade-mark) is a form of intellectual property that consists of a word, phrase, symbol, design, or a combination that identifies a product or service from a particular source and distinguishes it from others. Trademarks can also extend to non-traditional marks like drawings, symbols, 3D shapes like product designs or packaging, sounds, scents, or specific colours used to create a unique identity. For example, Pepsi® is a registered trademark associated with soft drinks, and the distinctive shape of the Coca-Cola® bottle is a registered trademark protecting Coca-Cola's packaging design. The primary function of a trademark is to identify the source of goods or services and prevent consumers from confusing them with those from other sources. Legal protection for trademarks is typically secured through registration with governmental agencies, such as the United States Patent and Trademark Office (USPTO) or the European Union Intellectual P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chocolates In Cellophane
Chocolate is a food made from roasted and ground cocoa beans that can be a liquid, solid, or paste, either by itself or to flavor other foods. Cocoa beans are the processed seeds of the cacao tree (''Theobroma cacao''); unprocessed, they taste intensely bitter. In making chocolate, these seeds are usually fermented to develop the flavor. They are then dried, cleaned, and roasted. The shell is removed to reveal nibs, which are ground to chocolate liquor: unadulterated chocolate in rough form. The liquor can be processed to separate its two components, cocoa solids and cocoa butter, or shaped and sold as unsweetened baking chocolate. By adding sugar, sweetened chocolates are produced, which can be sold simply as dark chocolate (a.k.a., plain chocolate), or, with the addition of milk, can be made into milk chocolate. Making milk chocolate with cocoa butter and without cocoa solids produces white chocolate. In some chocolates, other ingredients such as vegetable oils, emulsifier ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rayon
Rayon, also called viscose and commercialised in some countries as sabra silk or cactus silk, is a semi-synthetic fiber made from natural sources of regenerated cellulose, such as wood and related agricultural products. It has the same molecular structure as cellulose. Many types and grades of viscose fibers and films exist. Some imitate the feel and texture of natural fibers such as silk, wool, cotton, and linen. The types that resemble silk are often called artificial silk. It can be woven or knit to make textiles for clothing and other purposes. Rayon production involves solubilizing cellulose to allow turning the fibers into required form. Three common solubilization methods are: * The cuprammonium process (not in use today), using ammoniacal solutions of copper salts * The viscose process, the most common today, using alkali and carbon disulfide * The Lyocell process, using amine oxide, avoids producing neurotoxic carbon disulfide but is more expensive History French sci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinneret (polymers)
A spinneret is a device used to extrude a polymer solution or polymer melt to form fibers. Streams of viscous polymer exit via the spinneret into air or liquid leading to a phase inversion which allows the polymer to solidify. The individual polymer chains tend to align in the fiber because of viscous flow. This airstream liquid-to-fiber formation process is similar to the production process for cotton candy. The fiber production process is generally referred to as "spinning". Depending on the type of spinneret used, either solid or hollow fibers can be formed. Spinnerets are also used for electrospinning and electrospraying applications. They are sometimes called ''coaxial needles,'' or ''coaxial emitters.'' Spinnerets are usually made of metals with melting points too low to withstand the heating processes employed in industrial metallurgy, and thus are generally not used to form metallic fibers. See also * Electrospinning * Hollow fiber membrane * Spinning (polyme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer
A polymer () is a chemical substance, substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeat unit, repeating subunits derived from one or more species of monomers. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compound (chemistry), compounds, produces unique physical property, physical properties including toughness, high rubber elasticity, elasticity, viscoelasticity, and a tendency to form Amorphous solid, amorphous and crystallization of polymers, semicrystalline structures rath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
