Continuous Photo-flow Synthesis of Alkoxyamines

Aiming for a more sustainable future, biobased materials with improved performance are required. For biobased
vinyl polymers, enhancing performance can be achieved by nanostructuring the material, i.e. through the use of
well-defined (multi-)block, gradient, graft, comb, etc., copolymer made by controlled radical polymerization (CRP).
Dispoltec has developed a new generation of alkoxyamines, which suppress termination and display enhanced end
group stability compared to state-of-art CRP. Hence, these alkoxyamines are particularly suited to provide access
to such biobased nanostructured materials.
In order to produce alkoxyamines in a more environmentally benign and efficient manner, a photo-chemical step is
beneficial for the final stage in their synthesis. Photo-flow chemistry as a process intensification technology is
proposed, as flow chemistry inherently leads to more efficient reactions. In particular, photo-flow offers the benefit
of significantly enhancing reactant concentrations and reducing batch times due to highly improved illumination.
The aim of this project was to demonstrate at lab scale the feasibility of producing the new generation of alkoxyamines via a photo-flow process under industrially relevant conditions regarding concentration, duration and
efficiency. The project was carried out by Zuyd University of Applied Sciences (Zuyd), CHemelot Innovation and
Learning Labs (CHILL) and Dispoltec BV.
During this project, a microreactor set-up was built in which the photoflow synthesis of alkoxyamines could be
carried out in a succesfull manner. HPLC indicated full conversion of the starting compounds within 40sec
illumination. Quantification of the amount of the synthesized alkoxyamine is still under investigation – however, if
80% conversion towards the alkoxyamine is reached (HPLC suggests even higher), the current microreactor setup can already be used to produce 0.1 g of alkoxyamine per hour. As a future outlook, our students are currently
working on the upscaling of the photoflow reactor (5 mL instead of 20 µL) towards a more industrial scale

Aiming for a more sustainable future, biobased materials with improved performance are required. For biobased vinyl polymers, enhancing performance can be achieved by nanostructuring the material, i.e. through the use of well-defined (multi-)block, gradient, graft, comb, etc., copolymer made by controlled radical polymerization (CRP).
Dispoltec has developed a new generation of alkoxyamines, which suppress termination and display enhanced end group stability compared to state-of-art CRP. Hence, these alkoxyamines are particularly suited to provide access to such biobased nanostructured materials.
In order to produce alkoxyamines in a more environmentally benign and efficient manner, a photo-chemical step is beneficial for the final stage in their synthesis. Photo-flow chemistry as a process intensification technology is proposed, as flow chemistry inherently leads to more efficient reactions. In particular, photo-flow offers the benefit of significantly enhancing reactant concentrations and reducing batch times due to highly improved illumination.
The aim of this project is to demonstrate at lab scale the feasibility of producing the new generation of alkoxy-amines via a photo-flow process under industrially relevant conditions regarding concentration, duration and efficiency. To this end, Zuyd University of Applied Sciences (Zuyd), CHemelot Innovation and Learning Labs (CHILL) and Dispoltec BV want to enter into a collaboration by combining the expertise of Dispoltec on alkoxyamines for CRP with those of Zuyd and CHILL on microreactor technology and flow chemistry.
Improved access to these alkoxyamines is industrially relevant for initiator manufacturers, as well as producers of biobased vinyl polymers and end-users aiming to enhance performance through nanostructuring biobased materials. In addition, access in this manner is a clear demonstration for the high industrial potential of photo-flow chemistry as sustainable manufacturing tool. Further to that, students and professionals working together at CHILL will be trained in this emerging, industrially relevant and sustainable processing tool.