Microwave‐induced devulcanization for poly(ethylene–propylene–diene) recycling

Abstract

The production of high quantities of endof-life rubbers is an environmental problem of growing importance. Because of their crosslinked nature, such rubbers cannot be easily reprocessed, and actually, they are mainly wasted or reused after a simple mechanical grinding. In this study, a microwave (MW)-induced thermal treatment at temperatures above 300 C was proposed to obtain partial devulcanization of a poly(ethylene132#propylene-diene) (EPDM) rubber filled with carbon black. The use of MWs showed to be a very fast and simple technique, which allowed the production of a treated rubber with a relatively low degree of crosslinking, a slight revulcanization ability, and suitability for reuse in conjunction with virgin rubber. Preliminary mechanical characterization, performed on the revulcanized samples, indicated that the virgin and treated rubber were able to establish a good interface adhesion, which led to performances better than those of similar materials where the recycled part was made of ground untreated EPDM.

Devulcanization of styrene butadiene rubber by microwave energy: Effect of the presence of ionic liquid

“…EPDM being a non-polar rubber, microwave energy was transferred in the whole volume of the material via carbon black filler initially introduced as reinforcing particles. Bani et al [11] also performed similar studies and observed that the microwave devulcanization process was effective only beyond the heating temperature of 300°C. Landini et al [12] used a microwave technique to devulcanize bromobutyle (BIIR), and optimal power and time of treatment were identified as factors leading to the highest devulcanization proportion.…”

Effect of various efficient vulcanization cure systems on the compression set of a nitrile rubber filled with different fillers

“…The samples were dried in air for 9 h and then in an oven at 85 °C for 24 h, and allowed to stand for an extra 24 h at 23 °C before reweighing. The CLD was calculated using the υ is the volume fraction of rubber (polymer) in the swollen gel, and is the interaction parameter, which was calculated using the following equations: 29,30 = 0.429 + 0.218…”

Blends of ground tire rubber devulcanized by microwaves/HDPE - Part A: influence of devulcanization process

“…This feature, allied to the possibility of its revulcanization, indicates the wide applicability of the technique. Bani et al [11] demonstrated that microwaves can be applied easily and have many advantages, such as high heating rate, without any need of additional mechanical or chemical treatments.…”