Note that GSBR and DeVulcSBR-6(40) were extracted with hot toluene through Soxhlet extraction in order to remove the unreacted materials.
In fact, during devulcanization GSBR undergoes tremendous mechanical shearing resulting in scission in main chain as well as crosslink and thus we find a major dependence of sol content on devulcanization time.
As representatives the ATR spectra of GSBR, DeVulcSBR6(40) and TESPT are shown in Fig.
Since during the mechanochemical devulcanization of GSBR by TESPT, the fragmented TESPT free radicals are attached with DeVulcSBR, the peak at 1,165 [cm.sup.-1] for Si--O cage like stretching mode is seen in both TESPT and DeVulcSBR-6(40), and the peaks at 1,070 and 1,101 [cm.sup.-1] in TESPT and 1,077 and 1,101 [cm.sup.-1] in DeVulcSBR-6(40) for Si--O stretching of Si-alkoxy compound are observed but no such peaks are found in GSBR.
As the maximum degree of devulcanization of GSBR is obtained for DeVulcSBR-6s, the DSC study was performed by using DeVulcSBR-6.