About our research project
Polymers are used in such a wide range of applications that have shaped modernity. From daily tasks to our most technical needs, polymers have permeated every aspect of human life because they are uniquely capable of offering broad and customised properties. Today, the polymer industry is going through one of the most significant changes in priorities in its history. The polymer landscape is changing – in particular the manner they are manufactured and sold – driven by current and future environmental regulations in Europe and beyond, new energy supplies and technologies, and increasing consumer concerns about ecological issues. In this rapidly evolving context, one thing remains certain: the development of processes and products combining ecological and economic efficiency has become an absolute necessity. When it comes to eco-efficient processes and zero-VOC polymer products, two technologies stand out above all others in terms of production level, growth, and broad application spectrum: polymerisation in dispersed media and photopolymerisation.
Polymerisation in dispersed media – mostly emulsion and suspension – uses generally water as reaction medium, and already accounts for 20% of the world polymer production. The market size of emulsion polymers (latex) was estimated in 2016 at 17.7 million metric tons (dry basis) with an annual growth rate of 5.1%, exceeding that of polymers (3.5%). Latexes are used mainly in coatings, adhesives, inks, or non-woven textiles… Photopolymerisation is the second largest zero-VOC polymerisation process, applied today as a film curing technology in many industrial sectors, including inks, overprint varnishes, photoresists and industrial coatings. Relying mainly on UV light, it features 100% solids formulation, high productivity, and energy-saving process. Although radiation-curable products represent today a small percent of polymer market, but a growth rate over 10% is projected in 2017.
Today, there is a need to go beyond the current zero-VOC polymerisation technologies to expand the range of products and properties, and make the process even more efficient and eco-friendly. PHOTO-EMULSION aims at achieving these goals by using thiol-ene photopolymerisation in dispersed media. All commercial polymerisations in dispersed media rely currently on a radical chain-growth mechanism, using generally thermolatent or redox initiators inside conventional tank reactors. Our disruptive technology is distinguished by virtue of a photochemical initiation allowing temporal control, use of energy-efficient UV or visible LED lamps and photoreactors; and a step-growth thiol-ene polymerisation mechanism entailing ease of functionalization and architecture control, safer polymers devoid of residual monomer. The main approach begins with stable, highly reactive, low-scattering thiol-alkene nanodroplets (40-100 nm) dispersed in water, further converted into waterborne polysulfide dispersion by short exposure to light inside a professionally designed photoreactor (: Miniemulsion). Based on the same principle, nanodispersion in gas phase yields powder nanoparticles (: Aerosol), while porous polymers are produced from High Internal Phase Emulsions (: PolyHIPE) using a thiol-ene continuous phase. Our hybrid PROCESS paves the way to a novel range of high sulfur content dispersed polymer PRODUCTS, such as latex, films, powder nanoparticles, monoliths. The outstanding properties conferred in particular by sulfur — crystallinity, oxidability, coupling with noble metal, thiol reactivity — open the door to APPLICATIONS responding to current economic, ecological and social concerns in the EU such as non-leaching material, biobased painting, high barrier packaging film, and fast separation HPLC column.