INNOREX · Continuous, highly precise, metal-free polymerisation of PLA using alternative energies for reactive extrusion

The demand for biobased polymers is growing fast. According to the current state of the art, metal-containing catalysts are needed to improve the polymerisation rate of lactones, posing a hazard to health and the environment. InnoREX will develop a novel reactor concept using alternative energies for the continuous, highly precise, metal-free polymerisation of PLA.In InnoREX, metal-containing catalysts will be replaced by organic catalysts. These have been shown to efficiently control the polymerisation of lactide, but their activity must still be improved to meet industrial standards. This will be achieved by the low-intensity but highly-targeted application of alternative energies (microwaves, ultrasound, laser light). These energies increase catalyst activity and enable precise control of the reaction by exciting only small parts of the reaction mixture without response time.To ensure short market entry times commercially well-established co-rotating twin screw extruders will be used as reaction vessels. The reason commercial polymerisations are not yet carried out in twin screw extruders is the short residence time and the static energy input of the extruder, which allows no dynamic control of the reaction. Again, these obstacles will be overcome in InnoREX. The project will utilise the rapid response time of microwaves, ultrasound and laser light to achieve a precisely-controlled and efficient continuous polymerisation of high molecular weight PLA in a twin screw extruder. Additionally, significant energy savings will be achieved by combining polymerisation, compounding and shaping in one production step.For a deepened scientific and engineering understanding of the reaction, the effect of the alternative energies on the reaction kinetics and the potential applications for alternative energies in reactive extrusion, offline chemical and polymer analytics and online characterisation and simulation of the process within the reactor will be carried out.