So SOOW cable is made from a purer rubber than Solar/Polar cable? What does the slick/glossy jacket imply?
Purer is definitely the wrong term to use for this. It is made from a "rubber" which is engineered (with different chemistry, production process, additives of whatever) for superior properties in the particular areas that are considered important for this use.
For example, an outer layer that is more flexible in cold weather and oil resistant might have less abrasion resistance, for example.
As a general rule of thumb the more separate "good" qualities something has, the more expensive it will be, but not "purer."
In some areas there are different desirable qualities for one purpose that are simply in direct conflict with qualities for other purposes.
Some examples:
Ultra-flexibility is desirable for welding cables, but is not so good in tray cable for use in ladder type trays.
Fine stranded wire is good for pulling but bad for terminating in standard fittings.
Which one is purer?
PS: The slick glossy jacket might be for abrasion resistance or for oil resistance. Or something else entirely.
