It is a natural polymer of isoprene and it has elastic properties and it can undergo the long range of the reversible extension even by the application of small force. Due to this reason, it is also known as an elastomer or it is said as an example of elastomer polymer. After being stretched or deformed this polymer can retain to its original shape. In its resting state, the molecule of rubber is coiled. It has elastic properties due to the stretching of the chains apart, but when the tension is released, the chains are snapped back to their original position. In the majority of the rubber molecules, there are some units that are derived from the conjugated dienes monomers.
Natural rubber is a milky white fluid that is an addition polymer and it is obtained from the latex that is the colloidal solution of rubber in the water. There are trees of the rubber, which are found in tropical and semitropical countries. Natural rubber is a coiled structure and it does not have any straight chain, and resultantly it gets the elastic properties. No polar group is present in the structure of natural rubber. Due to this reason, the intermolecular and Vander wall forces of attraction are weak. These forces are further weakened due to the cis configuration of all the double bonds present in its structure and the close interaction of the polymer chain is not allowed. Most of the double bonds which are formed in the polymer chain of the natural rubber are z configuration which gives the elastomer qualities to the natural rubber.
In the present day, the plastic industry polymerization of dienes is done to make the substituents of the rubber. At first, synthetic rubber was obtained by the free radical polymerization of isoprene. This rubber has an all-trans configuration. Resultantly, the synthetic rubber is having a highly regular chain that is in the zig-zag fashion and cannot be stretched. This property accounts for the non-elastic nature of the synthetic rubber. Neoprene is the most important synthetic rubber. Polyurethane is also a synthetic rubber that is a versatile polymer and is used for the flexible and rigid foams coatings, bristles, fibers, and for the bumpers which are the automobile parts. It is also used as a binder for the paints and is used in the stretchable fabrics. Nowadays rubber is an indispensable thing for the various products and industries and in the modern-day world, it can be considered a necessity, and luxury.