POLYCHLOROPRENE CR:
Composing:
The CR in the heading stands for chloroprene rubber, more popularly known as Neoprene. Like all of the synthetic elastomers, CR is available to the rubber chemist in a number of grades to aid in compound mixing and to emphasize certain properties, such as reduction of crystallization rate in the vulcanizate.

Properties and Applications:
The oil resistance would only be considered moderate. CR has similar dynamic mechanical characteristics to NR, including good mechanical strength when it is compounded as a gum vulcanizate. CR has some ability to retard flame, which means that when a source of flame is removed, the burning polymer will have a tendency to self extinguish, (this can be modified to improve or unintentionally diminish this property), while NR, EPDM, and SBR for example, will continue to burn.Upper continuous heat aging resistance temperature limits are of the order of 90℃. Like a number of elastomers this can be raised somewhat by special compounding.

Resistance of CR to dilute acids and bases is better than that of NR or SBR, while cost is somewhat higher.