subject: Additives Necessary For Effective Processing Processing Of Rubber, Say Experts [print this page] Rubber is one of the most commonly used polymers today. Natural
rubber, which is the coagulated latex from certain types of trees that
grow in the tropics, has only monomers of isoprene, while synthetic
rubber can contain any of several types of monomer, but those must be
derived from petroleum.
At present, almost 70 percent of all rubber in use is synthetically
derived as the natural rubber is often too soft for heavy duty use.
Also, it retains a lot of moisture, which creates surface defects in
the end products if left untreated.
The rubber processors mix different chemicals with the rubber,
depending on its ultimate use. Amongst various processes, the most
widely known, and probably the most important is vulcaniszation.
In 1839, U.S. inventor Charles Goodyear determined that heating
natural rubber with sulfur resulted in a stronger product that was
more stable over a wide range of temperatures. He called this process
vulcanization and further discovered that he could quicken the process
by adding other substances as additives.
Vulcanization strengthens rubber because the sulfur links the polymer
chains into a stronger matrix.
However, rubber is not an easy polymer to disperse additives as it can
not be melted and converted to liquid form. For example, improper
dispersion of sulfur results in improper vulcanization. Physical
properties of improperly vulcanized rubber tends to vary from spot to
spot, often within the same batch.
This also results in a wastage of sulfur as the rubber processors tend
to add more than the ideally required quantity of sulfur to overcome
this defect.
India's leading manufacturer of niche additives for plastic and rubber
