The aim of this research was using a new chemical devulcanizing agent (i.e. VitaX) in devulcanization of NR/SBR blend as a model compound of tire rubber by microwave (MW) irradiation. For this purpose, the rubber compounds were prepared at different natural rubber (NR) to styrene butadiene rubber (SBR) ratios (40:60, 50:50, 60:40, 70:30 and 80:20). The rubbers were cured and then ground to particles with different mesh sizes (3, 4, 8, 16 and 30). The effect of irradiation time, stirring speed and particle size on sol/gel fractions, crosslink density (CLD) and devulcanization percent (DP) of the microwave irradiated samples was evaluated. Thereafter, effects of using VitaX and its content (0.3, 0.6, 1, 2, 3 and 4 phr) on devulcanized samples was evaluated. Results showed that using VitaX along with microwave irradiation caused decrease in the CLD and increase in the DP (from 9.51 to 34.85%) compared to the microwave assisted devulcanized samples. Finally, the raw NR/SBR rubber compound were replaced by different contents (10, 20 and 30 phr) of the chemical-microwave assisted devulcanized sample. The mechanical and curing properties of the samples were evaluated by tensile test and Oscillating Disk Rheometer (ODR), respectively. The results showed that at replacing content of 10 wt.%, decrement in the curing time and increment in the scorch time, cure rate index (CRI) and CLD was occurred in the re-vulcanized compound. The chemical-MW irradiation based devulcanization method was found to be a promising method for effective recycling of NR/SBR based rubbers such as tire rubbers.

本研究的目的是使用一种新的化学脱硫剂（即 VitaX）通过微波 (MW) 辐射对 NR/SBR 共混物进行脱硫，作为轮胎橡胶的模型化合物。为此，以不同的天然橡胶 (NR) 与丁苯橡胶 (SBR) 的比例（40:60、50:50、60:40、70:30 和 80:20）制备橡胶混合物。橡胶被固化，然后研磨成具有不同筛目尺寸（3、4、8、16 和 30）的颗粒。评估了辐照时间、搅拌速度和粒径对微波辐照样品的溶胶/凝胶分数、交联密度 (CLD) 和脱硫百分比 (DP) 的影响。此后，评估了使用 VitaX 及其含量（0.3、0.6、1、2、3 和 4 phr）对脱硫样品的影响。结果表明，与微波辅助脱硫样品相比，使用 VitaX 和微波照射会导致 CLD 降低和 DP 增加（从 9.51% 到 34.85%）。最后，用不同含量（10、20 和 30 份）的化学微波辅助脱硫样品代替未加工的 NR/SBR 橡胶混合物。分别通过拉伸试验和振动盘流变仪（ODR）评估样品的机械和固化性能。结果表明，当置换量为10wt.%时，再硫化胶料出现硫化时间减少和焦烧时间增加、硫化速率指数（CRI）和CLD。发现基于化学-MW 辐射的脱硫方法是有效回收 NR/SBR 基橡胶（如轮胎橡胶）的一种有前途的方法。