Experimental and application of waste rubber low‐temperature green regeneration through ultrasound‐assisted method

Abstract

Combining a traditional mixer and a custom‐built ultrasonic generator, low‐temperature green regeneration of waste rubber was realized. Through orthogonal experiments, the optimal process parameters for the low‐temperature green regeneration through the ultrasound‐assisted (LTGRTUA) method were explored. Results showed that the self‐developed reclaimed rubber exhibited the best performance under the following conditions: rotor speed of 70 rpm, regeneration temperature of 85°C, ultrasonic power of 700 W, and ultrasonic loading time of 240 s. Additionally, the bond‐breaking types of the reclaimed rubber were evaluated through the measurements of sol fraction and desulfurization rate, as well as by using the Horikx curve. The self‐developed reclaimed rubber showed better retention of the main chain structure of waste rubber compared to the commercially reclaimed rubber which was prepared by the traditional vulcanization tank high‐temperature regeneration (TVTHTR) method. Moreover, blending experiments were conducted, in which different proportions of the reclaimed rubber replaced natural rubber (NR) for the purpose of producing tread rubber for radial tires. Performance tests of the final products revealed that the self‐developed reclaimed rubber performed better than commercially reclaimed rubber, which provides an effective basis for the subsequent industrial application and promotion.Highlights Low‐temperature green regeneration of waste rubber was realized by the LTGRTUA method. The main chain structure of waste rubber is well preserved by the LTGRTUA method. The self‐developed reclaimed rubber has better properties and industrial application prospects.