Preliminary analysis to BIIR recovery using the microwave process

This paper shows the results of preliminary assessment to devulcanize and recover the bromobutyl rubber (BIIR) using the microwave process. In this work, a heat generating system with high microwave frequency (2.45 GHz) was used. Samples of BIIR (about 0.250 kg) such as rubber caps production leftovers and materials that had not been approved in the quality tests were irradiated, at powers of 1000 W, 2000 W and 3000 W. Various heating times were used: 540 s (9 min) up to 1500 s (25 min). The standard test specimens of non-irradiated and irradiated samples were characterized by rheometric analysis, Shore A hardness measurement and ash test. The best operation conditions were obtained at 780 s and 2000 W. The results showed that the microwave process caused an expressive effect in the BIIR recovery. Some samples presented the tendency to vulcanize again, hence there is a great expectancy for reusing and recycling the devulcanized BIIR, without using any chemical agent in the microwave process.