A short history of rubber cables

Several synthetic alternatives to natural rubber have been developed for the use in the electrical insulation applications. The properties of polymers are the result of molecular composition and structure. Compositionally, ethylene propylene rubber (EPR) is a hydrocarbon, having an unsaturated carbon backbone, dominated by linear -CH₂- and branched -CH- units, which are relatively stable and flexible building blocks for a polymer. The polymers that have a more random distribution of differing backbone units and/or branching points do not allow the polymer chains to organize very efficiently. Linear polymers that have only one type of backbone unit and no branching, such as found in some polyethylenes and polypropylenes, can organize much more easily. Their crystallinity leads to more rigid polymer networks, which is demonstrated by their physical properties such as high hardness, high modulus, and high tensile strength.