SELFNANOPUD

The project aims at the development of a new technology for the production of waterborne polyurethane dispersions for the creation of a new generation of coatings with self-healing properties. In the framework of the project, the design, synthesis and characterization of innovative dispersions and their coatings will be realized, as well as the optimization of their properties and the scaling-up of their production at semi-industrial scale.

In recent years, self-healing coatings have been the subject of increasing research interest. The ability of such coatings to self-repairing local damages caused by external forces is an important factor which contributes to their attractiveness and increasing demand. The process of self-healing of polymers is based on the dispersion of a catalyst and monomer-containing microcapsules into the polymeric matrix. Sufficiently large external stresses cause rupture of the microcapsules, releasing the monomer which diffuses through the polymer and eventually reaches a catalyst particle, causing the start of the polymerization reaction. The size and mechanical characteristics of the microcapsules constitute critical elements in controlling the self-healing process. The project aims at the development of aqueous polyurethane dispersions for one (PUR 1K) and two (PUR 2K) pack self-healing coatings with excellent chemical resistance properties, which will be derived through the polymerization reaction of polyols from renewable sources with isocyanate groups and encapsulation of micro/nanoparticles which will contain components with self-healing properties. At the same time, a thorough study towards the development of alternative materials with potential self-healing properties will be realised through the design and development of cross linkable surface functionalised copolymer nanoparticles and their subsequent incorporation into the polyurethane dispersions. In all cases mentioned above, there will be full control of all variables of each reaction. Different polyols and isocyanates will be tested and the impact on the polyurethane dispersions’ properties as well as the final performance of the self-healing coatings will be assessed. These innovative coatings will exhibit the classical properties associated with polyurethane coatings, including low volatile organic compounds (VOC) and excellent chemical resistance. The polyurethane dispersions, the micro/nanostructures and the final coatings will be fully characterised with regard to their morphology, their film forming properties, their surface, thermal, mechanical as well as their self-healing properties, while the best performing products will be produced also at the semi-industrial scale fulfilling the need for better waterborne self-healing coating systems. The successful implementation of the project will contribute to the replacement of solvent based with water-based products with significant positive implications on the competitiveness and improvements. in the production processes of the involved industrial companies in terms of their compliance with the environmental and technological requirements.