Devulcanisation

Elastomers or more commonly known as rubbers are for the most part polymers cross-linked by vulcanisation: bonds link the polymer chains and enable them to obtain the desired mechanical properties. However, these bonds prevent the mechanical recycling of these materials. Devulcanisation is a process that aims to break the cross-link bonds so that they can be reintroduced into a production cycle with virgin materials.

Diagram of the devulcanisation process where the vulcanisation bonds between the polymer chains are broken.
Diagram of the devulcanisation process*

Microwave radiation provides the energy needed to break down the cross-link bonds in the material.

Microwave reactor
Microwave reactor sample

The shear induced by the instrument promotes the rupture of the vulcanisation bonds.

Micro-extruder
Histogram showing the percentage of devulcanisation as a function of temperature T and extruder revolutions per minute (in RPM). At T1, RPM*1: 41%, RPM*2: 57% and RPM*3: 73%. At a temperature of T2, RPM*2: 81% and RPM*3: 93%.
% EPDM devulcanisation (T: temperature, RPM: Rotation Per Minute)

The scCO2 enables the material to swell, which breaks the cross-link bonds. It also encourages the penetration of devulcanising agents when used.

scCO2 static extraction autoclave

Ultrasonic waves provide the energy needed to break the cross-link bonds.

In addition to the experimental set-ups already in place, our team regularly develops and invests in new set-ups and instruments to meet specific needs.
So do not hesitate to contact us to discuss your specific requirements.