Bio NIPU, an Interreg Flanders-Netherlands project, focuses on the development of 100% bio-based and isocyanate-free polyurethane (bio NIPU) for end products in the textile and synthetic rubber industry.
The production of biopolymers for commercial applications increases year after year. However, biopolymers, such as polyurethane for textile coatings and synthetic rubber (elastomers), are only available for a limited number of applications and are not fully bio-based. Polyols and isocyanates are used for the synthesis of polyurethane.
As the EC adopted a regulation amending Annex XVII of REACH to restrict the use of diisocyanates on the EU market, the Bio NIPU project is researching alternative building blocks to synthesize polyurethane.
The project aims to develop a bio NIPU with a bio-based content of at least 80%.
To achieve this goal, we produced waterborne dispersions of bio-based NIPU (see left-hand picture) and designed NIPU dispersions with varying molecular weight and hydroxyl value.
The dispersions we have developed exhibit properties (particle size, particle size distribution) that are similar to the commercially available waterborne polyurethane dispersions.
In a next step, we applied the dispersions as an adhesive layer on a textile. The glass transition temperature was below -60 °C and the NIPU coating was tacky (picture above). As a topcoat we used a commercially available waterborne (bio-based) PU coating. After adding the processing additives in the adhesive and topcoat formulations, we applied the formulations by means of direct and transfer coating.
In the coming months we will assess the mechanical characteristics and performance of the bio-based NIPU coatings.
The BIO NIPU project partners
Acknowledgements
The Bio NIPU project is financed within the Interreg V program Flanders-Netherlands, the cross-border cooperation program with financial support from the European Regional Development Fund with co-financing from the province of East Flanders, the province of Antwerp, the Dutch Ministry of Economic Affairs and Climate and the Flemish government.