Composition of ...
A dynamic climbing rope is made of fibers from a polymer known as nylon 6,6. The chemical formula of nylon 6,6 is C12H22O2N2. The monomers of nylon 6,6 are hexamethylenediamine and adipic acid. Both of these monomers are organic compounds that are held together by an amide bond. These monomers form a long polymer chain that will eventually become large enough to be used as a fiber in the rope. Thousands of these fibers are twisted together to form a plain nylon string. Three of these strings are then braided together to make one of the 10-15 braided core strings. These strings are then packed tightly together and the sheath is woven around them. The sheath is made up of much flatter nylon strings accomplished by not twisting the the fibers together. These flat strings are then woven tightly together to form the protective layer around the core.
Main Chemicals, Compounds, Components
The two main compounds that combine to produce nylon 6,6 are hexamethylenediamine and adipic acid. The chemical formula of adipic acid is C6H10O4. This acid is produced by mixing cyclohexanol [(CH2)5CHOH] and cyclohexanone [(CH2)5CO] into an oil called ketone-alcohol oil. This oil is then oxidized with nitric acid [HNO3] to produce adipic acid. About 60% of all adipic acid produced is used for the synthesis of nylon 6,6. Hexamethylenediamine is the second monomer used in the production of the synthesis of nylon. The chemical formula of hexamethylenediamine is C6H16N2. This monomer is made by the hydrogenation of adiponitrile [(CH2)4(CN)2]. This bonds 4H2 to the adiponitrile forming hexamethylenediamine. This amine is produced only for the synthesis of nylon 6,6.
The two valence electrons on the nitrogen in the hexamethylenediamine are given to the carbon of the adipic acid. The sudden negativity of the nitrogen attracts it to the carbon and the bonding of these two atoms pushes the hydrogen from the hexamethylenediamine and the hydroxide from the adipic acid out of the newly formed polymer. The hydroxide and hydrogen molecules will combine to produce a water molecule. The polymer is then held together by the attraction between the nitrogen and carbon. This bond is called an amide bond. The hexamethylene has the nitrogens and hydrogens on both sides of the molecule and the adipic acid has the carbons and the hydroxides on each side of the molecule. This means that the amide bond will continue to form between the monomers to form the polymer chain and producing water as a byproduct. It will keep forming a fiber for as long as there is hexamethylenediamine and adipic acid to be combined.
The first dynamic climbing rope was developed in 1953 by Edelrid. It is dynamic because it stretches when a climber falls and puts it under pressure. This design of dynamic rope is called the kernmantle. The kern is the braided nylon core and the mantle is the the protective outer sheath of the rope. A 9.8mm diameter rope can take 5-10 completely static drops at 8kN. This is equivalent to about 1800 pounds being dropped from about 20 feet with absolutely no movement in the anchor point of the rope. All climbing ropes must pass these standard safety tests before they are to be distributed to climbers all over the world and are being used in all different types of rock climbing environments.
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Specifications of climbing rope
Percentage of diameter of the core and the sheath, stretch percent, and what makes a rope dynamic or static
This is a site that explains the chemistry behind different objects and products
How the nylon is bonded together and made
What type of nylon is used for climbing rope
This site gives information and specification on many different polymers
The chemical formula of nylon
Diagram of the structure of the chain of nylon to form into fibers and eventually ropes
Other properties of nylon
Melting point, molecular weight, and density
The detailed step by step production of the nylon core and nylon sheath climbing ropes at Mammut
The sheath is woven around the core strings of the rope
Gives a list of detailed and extensive physical and chemical characteristics of the molecules of nylon that make up climbing rope
Other uses, durability, elongation, weaknesses
This is a site that answers scientific questions
What monomers are involved
Adipic Acid and Hexamethylenediamine
What reaction creates nylon
The history of the kernmantle rope design
Specifications of the dynamic climbing rope
Breaking strength and testing that it must undergo to meet quality standards of the manufacturer
Details on Hexamethylenediamine
How it is made and what other applications it has
Details on Adipic acid
Cyclohexanol and cyclohexanone mixture oxidized with nitric acid to produce adipic acid
How hydrogenation works
Combines 4 H2 with adiponitrile to create hexamethylenediamine
This site gives statistics on causes of injuries and deaths related to different outdoor sports
Statistics on climbing deaths related to total gear failure
This site provides a detailed explanation of the process of the synthesis of nylon 6,6
The structure of the two monomers and how they are bonded together to form the polymer chain
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