Polyolefin:
It is one of largest group of organic thermoplastic polymers [1] as well as because it’s non-porous or non-polar and odorless material that is used in structural plastics, consumer goods, food packaging and industrial products. Polyolefin states “oil like” and is commonly cited to as thermoplastic or polyalkene has a waxy texture. This type of compound for the most part utilized in the field of research and production in the petrochemical and organic chemistry industries.
The production of polyolefin was started in the research laboratories. Polyethylene was the first created polyolefin in 1933 at Imperial Chemical Company by E.W. Fawcett and R.O. Gibson. The production of polyolefin is expected to achieve 100 million of metric
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The first fiber was made-up from polyamide polymers were created in 1938 at USA and Germany. In USA the raw materials, used to create the polymer was adipic acid and hexamethylene diamine and since both chemicals contain 6 carbon atoms the new polymer was named polyamide 6.6. In Germany caprolactam was polymerised to produce a different fiber known as polyamide 6. [4]
Polyamides are either created by the reaction of a diacid with a diamine chemical change of lactams. They are either all aliphatic or aromatic. The aromatic polyamides known as aramids, have better solvent, flame and heat resistance, greater dimensional stability and higher strength, than the all aliphatic amides but a lot of pricey and tougher to produce. The two most important aromatic amides are poly(p-phenylene terephthalamide), called as Kevlar, and poly(m-phenylene isophthalamide). The fully aromatic structure and the hydrogon bonds between the aramid chains leads to high melting points, generally higher than their decomposition temperature > 750 K excellent flame, heat resistance and ultra high tensile strength at low weight.
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They are amorphous or solely moderately crystalline once injection shaped, but the degree of crystallinity will be abundant redoubled for fiber and film applications by orientation via mechanical stretching. The two most vital polyamides poly(hexamethylene adipamide) Nylon 6,6 and polycaprolactam Nylon 6. Both have wonderful mechanical properties together with high impact strength, high flexibility, high tensile strength, good resilience and low creep. They are straightforward to dye and exhibit wonderful resistance to wear due to a low constant of friction. Both amides have a high melting temperature (500 - 540 K) and glass transition temperature reports in excellent mechanical properties at elevated temperatures. For example, the heat rebound temperature of PA-6, 6 is usually between 180- 240°C that exceeds those of polycarbonate and polyester. They also have excellent resistance to fungi, oils, bases, etc. The main limitation is that the strong wet sensitivity water acts as a plasticizer and therefore the ensuring changes in mechanical properties. For example, the tensile strength of moist polyamide is 50% below that of dry polyamide. Another important polyamide is Nylon 6,12. It is less hydrophilic than Nylons 6,6 and 6 due to the larger range of chemical group of methylene within the compound backbone. For this reason, it has better dimensional
spaced –CONH– amide groups. Nylon 6-6, or poly(hexamethylneadipamide), is composed of. two structural monomers (hexamethylendiamine (H2N(CH2)6NH2) and adipic acid. (HOOC(CH2)4COOH), whereas Nylon 6, or poly(6-caprolactam), is composed of a single structural unit (either 6-aminocaproic acid (H2N(CH2)4COOH) or caprolactam). Ultimately, the answer is yes.
In 105 CE a man named Cai Lun during the Eastern Han Dynasty invented the paper from worn fishnet, bark and cloth. These materials were used because they could be easily found at a low price compared to Hemp fiber and silk. Hemp fiber and silk were used at first but then the Chinese realized there are greater uses for this material. Therefore they started to use the worn fishnet, bark and
Fire and thermal properties of PA 66 resin treated with poly-N- aniline- phenyl phosphamide as a flame retardant
Controlling chemiluminescent light was how Omniglow Incorporated became the first company to produce light sticks. In 1986, when the first light stick was invented, scientists thought they could make a lot of money selling light sticks. However, since they had to make light sticks by hand, it was harder for them to produce very many of them. Until machines were invented to make light sticks, it cost too much money to make them by hand.
A natural protein fiber, called wool, was discovered before 10,000 B.C.E. and woven into cloth by 1900 B.C.E. Wool comes predominantly from sheep but is also found in other animals such as, llamas, alpacas, camels and goats. Tribes in North Europe spun wool using a crude spindle, which is a stick with a stone or clay ring connected to the end to make yarn. They also made wool into cloth by weaving the thread in a criss cross style. Some humans 8,000 years ago domesticated sheep specifically for the production of wool and other uses. 4,000 B.C.E. - 4,000 B.C.E.
rapid development of polymer chemistry after World War II a host of new synthetic fibers
The Crystallinity of Kevlar Polymer strands, contributes to the unique strength and stiffness of the material. Kevlar is very similar to other common synthetic polymers, including Nylon, Teflon and Lycra. In all Polated to strength. Aromatic refers to the Carbon atoms attached in a ring, and Amides refers to a group of Carbon, Nitrogen and Hydrogen atoms. Kevlar fiber is therefore a “Polyaromatic amide”, as it has a high breaking strength.
There are two types of synthetic polymers which are called condensation and addition polymers. The condensation polymers result when there is a reaction between two poly functional molecules which gets rid off a small molecule. For example, the polyester Dacron is a synthetic condensation polymer. Addition polymers on the other hand are formed in a domino effect including monomers with double bonds. Once the polymers are formed they tend to take on a linear shape or a star/comb like shape and then they are classified as linear and branched polymers. There are four major biological macromolecules which are carbohydrates, lipids, proteins and nucleic acids. Carbohydrates are sugar molecules that are made from C, H and O in a 1:2:1 ratio. Monosaccharides and disaccharides are carbohydrates divided into simple sugars while polysaccharides are carbohydrates that are divided into complex sugars such as starch. Lipids are substances like fat and phospholipids are important components of all living creatures. They are hydrophobic and thus it is difficult to break down to form energy. Biological polymers are made of amino acids, nucleotides and sugars. A significant biological polymer
Polyethylene (PE) is one of the most commonly used polymers which can be identified into two plastic identification codes: 2 for high-density polyethylene (HDPE) and 4 for low density polyethylene (LDPE). Polyethylene is sometimes called polyethene or polythene and is produced by an addition polymerisation reaction. The chemical formula for polyethylene is –(CH2-CH2)n– for both HDPE and LDPE. The formation of the polyethylene chain is created with the monomer ethylene (CH2=CH2).
Polymer-Polyethylene is partially crystalline as well as amorphous because it has crystalline and amorphous regions. Also it has linear chains so this is the simplest structure compared to a branched or network chain. This can be of an advantage to it over other types of materials as its good toughness and elongation makes it very significant in the engineering industry as it can be moulded or extruded into shape...
German Chemist Hans von Pechmann first synthesized Polyethylene by accident in 1898 by heating diazomethane. His colleagues characterized the waxy substance polyethylene due to the fact that they recognized that it consisted of long ethene chains. It was then first industrially synthesized by accident in 1933 by applying extremely high pressure to ethylene and benzaldehyde. Over the years, development of polyethylene has increased due to the additions of catalyst. This makes ethylene polymerization possible at lower temperatures and pressures.1
Carbon fibers were discovered in the late 1800s by Thomas Edison. The early lightbulbs Edison created used the carbon fibers as filaments. These carbon fibers used to create the early lightbulbs had a substantial tolerance to heat, but they lacked the tensile strength of modern carbon fibers. Edison used cellulose-based materials, such as cotton or bamboo, to make his carbon fibers. He used a method called “pyrolysis” to cook the bamboo at high temperatures in a controlled atmosphere to carbonize bamboo filaments, making them fire-resistant and capable of enduring intense heat needed for luminescence.
Morris Zief and Elias Yanovsky, US Patent No. 2,606,881, Polymerization of poly allyl and poly methallyl ethers of poly hydroxy compounds, (Aug. 12, 1952)
To begin with, the inventor of the paper was a man by the name of Cai Lun. He was born in Guiyang, China during the Eastern Han Dynasty in 50 C.E. During his older years, he served as a court eunuch and became a paperwork secretary. Before his invention, ancient China tried bark, fishnets, seaweed, rice, straw, grass, and numerous other things to make paper out of. The day came in 105 C.E. when Cai