Mechanochemical Regeneration Of Waste Rubber And Its Structure And Properties

Rubber products have been widely used among industries because of its excellent elastic property, while waste rubber has also increased fast. As most rubber products were processed by vulcanization and filled by carbon black, stable 3-dimensional network structure were formed, so waste rubber was hard to be melted or dissolved and therefore difficult to be recycled effectively. Polymer mechanochemical method was an interdisciplinary subject which was found between polymer chemistry and mechanics. In this paper, mechanochemical method was used to reclaim waste rubber powder.The recipe of reclaiming material were discussed, and when the amount of reclaiming agent(TETA) was 4 phr, we could get the best regeneration result. And open mill process was found much more effective than the internal mix process, the best process parameters during mechanochemical process were:70℃ and 10 min milling. Response surface analysis was used to detect the synergistic effect of parameters in the reclaiming process, and predicted as well as verified the best reclaiming process parameters.FTIR and GPC were used to analyze the micro-structure of reclaimed rubber, found that the reclaiming process mainly broke the sulfur crosslinking bonds and to a large extent left the rubber main chains intact. XPS and EDS were used to analyze the surface elements change of rubber before and after regeneration, found that the content of C element basically remained still, S element dropped and O element increased a bit, which proved that the process have broken the crosslinking bonds of waste rubber, after regeneration some sulfur escaped from rubber by forming sulfur compounds and O elements from air combined with rubber chain. Swelling behavior and thermal analysis of reclaimed rubber showed that the dense structure of waste rubber was destroyed and lots of flexible rubber main chains were generated. SEM images also indicated that rigid waste rubber powders turned into sticky and plastic polymer after regeneration.Vulcanization properties of reclaimed rubber were also tested through disc-rheometer and the curing curve was fitted with S curve. Mechanic Properties of vulcanizates with sulfur and accelerators were excellent.