One of the various problems which mankind faces as it enters into the 21st century is the problem of waste disposal
management. Since polymeric materials do not decompose easily, disposal of waste polymers is a serious environmental
problem. Large amounts of rubbers are used as tires for aeroplanes, trucks, cars, two-wheelers etc. But after a
long run when these tires are not serviceable and discarded, only a few grams or kilograms of rubber (,1%) are
abraded out from the tire. Almost the entire amount of rubber from the worn out tires is discarded, which again
need very long time for natural degradation due to crosslinked structure of rubbers and presence of stabilizers and
other additives. This poses two major problems: the wastage of valuable rubber and the disposal of waste tires
leading to environmental pollution. Two major approaches to solve this problem are the recycle and the reuse of
used and waste rubber, and the reclaim of rubber raw materials. q 2000 Elsevier Science Ltd. All rights reserved.