The Structure and Properties of Ink-jet Printed Photo-curable in-situ polymerization Cationic Aqueous Dispersion Polyurethane Acrylate/Silica

A series of photo-curable in-situ polymerization cationic aqueous dispersion polyurethane acrylate/Silica for digital ink-jet printing was designed and synthesized by incorporating N-Methyldiethanolamine (MDEA) as the... [ view full abstract ]

A series of photo-curable in-situ polymerization cationic aqueous dispersion polyurethane acrylate/Silica for digital ink-jet printing was designed and synthesized by incorporating N-Methyldiethanolamine (MDEA) as the hydrophilic chain extender, 2-hydroxyethyl acrylate (HEA) as Photosensitive reactive capping agent and in-situ grafted by 3-Aminopropyltriethoxysilane (AMEO) modified Silica at the end of macromolecular chain. The structure of synthesized PUAs oligomer were confirmed by infrared spectroscopic analysis, 1H-NMR, and free NCO root titration. The characterization of rheology and laser particle size analysis indicated the oligomer is a typical shear thinning polymer fluid while the WPU/Silica can emulsify stably in the system of water and salted by acetic acid (Ac) which having a solid content of 33%. Silica was well dispersed in organic particles. The system had excellent compatibility and storage stability. The dispersions were effectively cured under Blue light/UV LED lamp, initiated by 3% of Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) and copolymerized with acrylate. The investigation illustrated the Photo-curable in-situ polymerization Cationic waterborne Polyurethane Acrylate/Silica film effectively forming a semi-interpenetrating network system to achieve rapid curing coating. The results showed the product cured by WPU/Silica dispersion of R=1.5 mixed with equimolar HEA obtained low yellowing, the maximum breaking strength, high elongation at break, Low modulus, high thermal decomposition temperature, high crystallization temperature of hard segment, low glass transition temperature of soft segment, high degree of phase separation, better optically transparent performance, which can widely be applied for 3D digital ink-jet printing.