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Query: What is the most common natural polymer?
People have been using natural organic polymers for centuries in the form of waxes and shellac, which is classified as a thermoplastic polymer. A plant polymer named cellulose provided the tensile strength for natural fibers and ropes, and by the early 19th century natural rubber was in widespread use. Polymers are the raw materials (the resins) used to make what are commonly called plastics. Plastics are the final product, created after one or more polymers or additives have been added to a resin during processing, which is then shaped into a final form. Polymers that have been around, and that are in current widespread use, include carbon-based polyethylene, polypropylene, polyvinyl chloride, polystyrene, nylons, polyesters, acrylics, polyurethane, and polycarbonates, and silicon-based silicones. Plastics are generally classified as "commodity", "specialty" and "engineering" plastics.
Most natural polymers being employed at early stage of human society are of condensation type. The synthesis of first truly synthetic polymeric material, Bakelite, was announced by Leo Baekeland in 1907, through a typical step-growth polymerization fashion of phenol and formaldehyde. 
The pioneer of synthetic polymer science, Wallace Carothers, developed a new means of making polyesters through step-growth polymerization in 1930s as a research group leader at DuPont. It was the first reaction designed and carried out with the specific purpose of creating high molecular weight polymer molecules, as well as the first polymerization reaction whose results had been predicted beforehand by scientific theory. Carothers developed a series of mathematic equations to describe the behavior of step-growth polymerization systems which are still known as the Carothers equations today. Collaborating with Paul Flory, a physical chemist, they developed theories that describe more mathematical aspects of step-growth polymerization including kinetics, stoichiometry, and molecular weight distribution etc. Carothers is also well known for his invention of Nylon.
Polyvinyl ethers are a class of organic polymers derived from vinyl ethers. The most common polymers of this class are derived from methyl vinyl ether and ethyl vinyl ether, the polymer having the formula [CHCH(OCH)]. Commercial interest has also focused on polymers derived from ethyl, isobutyl, octadecyl substituents in place of methyl. Like other vinyl polymers, the polymers exhibit tacticity. Polymerization is typically initiated with Lewis acids such as boron trifluoride.
DNA, RNA and proteins are most common sequence-controlled polymers in living creatures. Inspired by them, polymerization methods, utilizing DNA or RNA as templates to control sequences of polymer, are developed. At first, taking DNA or RNA as templates, scientists developed a series of peptide nucleic acid (PNA)-based polymers, without using DNA polymerases. But this method is limited to polymerization scale and yield. After that, polymerase chain reaction (PCR) is developed, which currently is still the most extensively used sequence-regulated method. By employing enzymes, the yields and scales are greatly increased, but the specificity of enzymes towards natural peptides limits this technique to a certain degree. Nowadays, more attention is paid to utilization of ribosomes to directly mimic the transcription and translation process. This technology called protein engineering is considered as the most promising biological polymerization method for synthesis of sequence-controlled polymers.
When Wallace Carothers arrived at DuPont in 1928 one of the tasks his group took on was the development of new synthetic fibers for textiles. At that time a number of natural polymers such as latex and cellulose were in common use, rayon as a semisynthetic from nitrated cellulose had recently been improved and begun upending the textile industries, and some fully synthetic polymers such as bakelite were also known and being used for certain applications, but the existing fully synthetic polymers could not be drawn into fibers and spun into thread, so great opportunity existed to manufacture thread and yarn from synthetic polymers to join or replace the existing fibers in the market (natural fibers such as cotton, wool, linen, and silk and artificial fiber in the various recently emerged types of rayon).
In 1884 Hilaire de Chardonnet started the first artificial fiber plant based on regenerated cellulose, or viscose rayon, as a substitute for silk, but it was very flammable. In 1907 Leo Baekeland invented the first synthetic polymer, a thermosetting phenol-formaldehyde resin called Bakelite. Around the same time, Hermann Leuchs reported the synthesis of amino acid N-carboxyanhydrides and their high molecular weight products upon reaction with nucleophiles, but stopped short of referring to these as polymers, possibly due to the strong views espoused by Emil Fischer, his direct supervisor, denying the possibility of any covalent molecule exceeding 6,000 daltons. Cellophane was invented in 1908 by Jocques Brandenberger who treated sheets of viscose rayon with acid.
Polyolefin is one of the softest synthetic string materials, rivaling some Zyex and most nylon multi-filaments. It offers mediocre durability and tension retention, so it is generally used as the cross string in a hybrid string setup. For those who do not break strings very quickly, however, 100% polyolefin stringing may be a good alternative to natural gut and multi-filament strings. This is especially true for those who have had tennis elbow and find natural gut string to be too costly.
In the same year, Dr. Julian W. Hill, another member of the Carothers team, began work again on attempting to produce a polyester with a molecular weight of above 4,000. His efforts were soon met with great success when he produced a synthetic polymer with a molecular weight of about 12,000. The high molecular weight allowed the melted polymer to be stretched out into strings of fiber. Thus was created the first synthetic silk, described by the chemists as a superpolyester.
The world's first fully synthetic plastic was bakelite, invented in New York in 1907 by Leo Baekeland who coined the term 'plastics'. Many chemists have contributed to the materials science of plastics, including Nobel laureate Hermann Staudinger who has been called "the father of polymer chemistry" and Herman Mark, known as "the father of polymer physics".
Raw natural gas consists primarily of methane (CH), the shortest and lightest hydrocarbon molecule, as well as various amounts of heavier hydrocarbon gases such as ethane (CH), propane (CH), normal butane ("n"-CH), isobutane ("i"-CH), pentanes and even higher-molecular-mass hydrocarbons. The raw gas also contains various amounts of acid gases such as carbon dioxide (CO), hydrogen sulfide (HS) and mercaptans such as methanethiol (CHSH) and ethanethiol (CHSH).
While known since 1954, PGA had found little use because of its sensitivity to hydrolysis when compared with other synthetic polymers. However, in 1962 this polymer was used to develop the first synthetic absorbable suture which was marketed under the tradename of Dexon by the Davis & Geck subsidiary of the American Cyanamid Corporation. After its coating with Polycaprolactone and Calcium Stearate is being sold under the brand name of Assucryl.
Polycyclic aromatic hydrocarbons are discussed as possible starting materials for abiotic syntheses of materials required by the earliest forms of life.
Many cellulosic biomass materials produce methane naturally. Methane is the main component of natural gas. Naturally occurring methane is often considered a source of pollution from landfills, dairy farms, and human waste sources. The EPA routinely issues rules to reduce the emission of methane from landfills and other sources.
PVC was accidentally synthesized in 1872 by German chemist Eugen Baumann. The polymer appeared as a white solid inside a flask of vinyl chloride that had been left exposed to sunlight. In the early 20th century the Russian chemist Ivan Ostromislensky and Fritz Klatte of the German chemical company Griesheim-Elektron both attempted to use PVC in commercial products, but difficulties in processing the rigid, sometimes brittle polymer thwarted their efforts. Waldo Semon and the B.F. Goodrich Company developed a method in 1926 to plasticize PVC by blending it with various additives. The result was a more flexible and more easily processed material that soon achieved widespread commercial use.
The molecular weight of the polymer is perhaps one of the most important properties to consider when determining antimicrobial properties because antimicrobial activity is markedly dependent on the molecular weight. It has been determined that optimal activity is achieved when polymers have a molecular weight in the range of 1.4x10 Da to 9.4x10 Da. Weights larger than this range show a decrease in activity. This dependence on weight can be attributed to the sequence of steps necessary for biocidal action. Extremely large molecular weight polymers will have trouble diffusing through the bacterial cell wall and cytoplasm. Thus much effort has been directed towards controlling the molecular weight of the polymer.
Graphene was discovered at the University of Manchester in 2004 under Prof Sir Andre Geim and Sir Konstantin Novoselov.
At the Calico Printers' Association in Manchester in 1941, John Rex Whinfield and James Tennant Dickson discovered polyethylene terephthalate, known as PET, a common polyester compound found in plastic bottles and food, and also known as Terylene or Dacron. Cheslene and Crepes of Macclesfield discovered crimplene (the fabric that is now referred to as polyester). ICI Dyestuffs at Hexagon House, in Blackley in north Manchester, discovered Procion dyes. At the Winnington Laboratory on 27 March 1933, Eric Fawcett and Reginald Gibson discovered polythene in an ICI laboratory in Northwich, when reacting benzaldehyde with ethene at a pressure of 2,000 atmospheres; the process was improved in 1935 by Sir Michael Perrin.
Schizophyllan has a molecular weight of 450,000 Da, and a specific rotation in water of +18-24°. A chemically analogous polysaccharide, scleroglucan, is formed by the fungus "Athelia rolfsii". Both polysaccharides share the chemical structure of the backbone with curdlan. It is known for several things, including its ability to stimulate the immune system, carry metals in water, aid in delivering drugs, and use in some nanofibers.
A balloon is an inflatable flexible filled with air and also gas, such as helium, hydrogen, nitrous oxide or oxygen. Modern balloons can be made from materials such as Natural latex rubber, polychloroprene, or a nylon fabric, while some early balloons were made of dried animal bladders . latex rubber balloons are used for children playing amusement it is cheap toys for rural people's children it also use as decorative purposes, while others are used for practical purposes such as meteorology, medical treatment, military defense, or transportation. A balloon's properties, including its low density and low cost, have led to a wide range of applications. The inventor of the natural latex rubber balloon, (the most common balloon) was Michael Faraday in 1824, via experiments with air and various gases.
Comprising 75% of the biological world and 80% of all food intake for human consumption, the most common known human carbohydrate is Sucrose. The simplest version of a carbohydrate is a monosaccharide which contains carbon, hydrogen, and oxygen in a 1:2:1 ratio under a general formula of CHO where n is a minimum of 3. Glucose is an example of a monosaccharide as is fructose. Combine them in the picture shown to the right and you have sucrose, one of the more common sugar products around.
Electrical wires are usually covered with insulating materials, such as plastic, rubber-like polymers, or varnish. Insulating and jacketing of wires and cables is nowadays done by passing them through an extruder. Formerly, materials used for insulation included treated cloth or paper and various oil-based products. Since the mid-1960s, plastic and polymers exhibiting properties similar to rubber have predominated.
Dr. Joseph Cecil Patrick (August 28, 1892 – April 12, 1965) invented Thiokol, America's first synthetic rubber in the early 1920s. While seeking a formulation for automotive antifreeze, he attempted to hydrolyze ethylene dichloride with sodium polysulfide. In doing so, he produced a brown, insoluble gum that later became known as Thiokol. He solved commercial production problems by inventing the suspension polymerization process, and solved compounding problems by degrading high molecular weight polymer to a low molecular weight liquid polymer. This material is one of the principal binders for rocket propellant.
Just like erosion of rocks, natural phenomena can cause degradation in polymer systems. The elements of most concern to polymers are ultraviolet radiation, moisture and humidity, high temperatures and temperature fluctuations. Polymers are used in everyday life, so it is important for scientists and polymer producers to understand durability and expected lifespan of polymer products. Paint, a common polymer coating, is used to change the colour, change the reflectance (gloss), as well as forming a protective coating. The structure of paint consists of pigments in a matrix of resin.
A typical example is painted steel roofing and walling products, which are constantly exposed to harmful weathering conditions.
Inorganic polymers are polymers with a skeletal structure that does not include carbon atoms in the backbone. Polymers containing inorganic and organic components are sometimes called hybrid polymers, and most so-called inorganic polymers are hybrid polymers. One of the best known examples is polydimethylsiloxane, otherwise known commonly as silicone rubber. Inorganic polymers offer some properties not found in organic materials including low temperature flexibility, electrical conductivity, and nonflammability. The term "inorganic polymer" refers generally to one-dimensional polymers, rather than to heavily crosslinked materials such as silicate minerals. Inorganic polymers with tunable or responsive properties are sometimes called smart inorganic polymers. A special class of inorganic polymers are geopolymers, which may be anthropogenic or naturally occurring.
The Cohen brothers were looking for a commercial edge and became aware, in 1894, that Charles Cross, Edward Bevan and Clayton Beadle had patented their "artificial silk" which they named "Viscose" in the UK and "Rayon" in the US, and sold under the trade name "Dacron". Although natural polymers have been with around since time began, synthetic polymers are more recent and owe their origin to Alexander Parkes and his exhibits at the International Exhibition in London in 1862. The most basic building block of a polymer is a monomer, which, when combined with oxygen, nitrogen, chlorine, or fluoride, becomes a "polymers". The most important polymer, for fabric construction is Polyethylene terephthalate, more commonly known as "polyester". The bright vibrant synthetic fabrics made from these synthetic "building blocks" exhibit a silk "handle"; and all the comfort properties of natural fibres, imitating silk, wool and linen.
A polymer is a macromolecule, composed of many similar or identical repeated subunits. Polymers are common, but not limited to organic media. They range from familiar synthetic plastics to natural biopolymers such as DNA and proteins. Their unique elongated molecular structure produces unique physical properties, including toughness, viscoelasticity, and a tendency to form glasses and semicrystalline structures. The modern concept of polymers as covalently bonded macromolecular structures was proposed in 1920 by Hermann Staudinger.
One sub-field in the study of polymers is polymer physics. As a part of soft matter studies, Polymer physics concerns itself with the study of mechanical properties and focuses on the perspective of condensed matter physics.