Benzene is an important organic chemical compound with the chemical formula C6H6. The benzene molecule is composed of 6 carbon atoms joined in a ring with 1 hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon. Benzene is a natural constituent of crude oil and is one of the elementary petrochemicals. Because of the cyclic continuous pi bond between the carbon atoms, benzene is classed as an aromatic hydrocarbon, the second [n]-annulene ([6]-annulene).
Synthetic round slings offer a number of advantages for rigging purposes. The most commonly used synthetic round slings are made of nylon- or polyester-type yarns. Each synthetic material has its own unique properties. Certain synthetic materials perform better than others in specific applications and environments.
Short-fiber reinforced composites are made from keratin fibers obtained from poultry feathers and polyethylenes of varying crystallinity. The chemical nature of the polymer and fiber is kept constant and the molecular architecture of the polymer is varied. It is found that low crystallinity polyethylenes are reinforced by keratin fibers but high crystallinity polyethylenes are not.