Bio-based UV-curing varnishes with good properties
Scientists have synthesized fully bio-based branched unsaturated polyester oligomers for UV-curable coatings.
In a recent work, fully bio-based branched unsaturated polyester (BUPE) oligomers were synthesized by one-step solvent-free polycondensation using itaconic acid, isosorbide and glycerol as starting materials. The branched structure was observed by Fourier transform infrared spectroscopy (FTIR) and proton magnetic resonance spectroscopy (1H NMR) confirmed. It was investigated how the branched structure affects the properties of the UV-curing BUPE coatings.
The results showed that the introduction of a branched glycerol structure favors UV curing. The UV-curable BUPE coatings based on the branched glycerin structure had higher gel content and cross-link density, which improved the hardness, solvent resistance and mechanical properties of the coatings. In addition, the UV-curable BUPE coatings had extremely low surface roughness, excellent heat resistance and excellent light transmission properties.
Source: Color & Varnish and Journal of Coatings Technology and Research, Volume 20, Issue 5, September 2023