cis-1,4 polyisoprene
Quick Summary
cis-1,4 polyisoprene is a polymer of isoprene, a hydrocarbon with the formula C5H8. This compound is the primary component of natural rubber, as well as naturally occurring resins like balata and gutta-percha. It can also be produced synthetically.123
The properties of polyisoprene depend on its molecular structure. The cis-1,4 isomer is characteristic of natural rubber, known for its exceptional extensibility and toughness. It can be stretched significantly and its molecules align when stretched, increasing strength. However, natural rubber is sensitive to temperature, becoming brittle when cold and soft when hot. It also degrades when exposed to oils, oxygen, and ozone. These issues are often addressed through vulcanization.14
Synthetic isoprene rubber is manufactured to closely mimic natural rubber, though it may not be as perfectly structured. Both natural and synthetic forms are widely used in tires, footwear, and adhesives. The trans-1,4 isomer, found in gutta-percha and balata, results in tougher, leathery materials used for applications like golf ball covers.142
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