Synthesis of stable cationic waterborne polyurethane with a high solid content: insight from simulation to experiment

Abstract

Stable cationic waterborne polyurethanes (CWPUs) with a high solid content (HSC) were synthesized via the combination of cationic ionic and nonionic segments (polyoxyethylene alkyl amine, PAE). The process was based on an iterative strategy to design the cationic groups in soft segments and the chain terminal of polyurethanes (terminal ions) together with the determination of the optimal bimodal particle size distribution (PSD). The effects of the polymerization degree of poly(ethylene glycol) groups (PEG-g) in PAE and its interaction with the hydrophilic groups N-methyl diethanolamine (MDEA) in polyurethane were studied. It was found that the terminal ions resulted in a much finer dispersion, better dispersion stability, smaller particle size and lower viscosity. Moreover, the highest solid content (52.18%) of CWPU was obtained by the incorporation of PAE and a low terminal ions content of 2.5%, which had a bimodal particle size distribution. The increasing length of PEG-g was also found to enhance the thermal stability and render a better mechanical stability for the polyurethane films as the increasing PEG-g length may weaken the hydrogen bonding and reduce the extent of phase separation. The experimental results were further compared with molecular dynamic simulation results, which verified that the specific molecular structure of this WPU ensured its excellent properties. The static structure and dynamic properties obtained strongly supported the experimental observations reported on the morphology and thermal and mechanical properties of these polyurethanes.

Tailoring of Durable Conductive and UV-Shielding Properties on Cotton and Polyester Fabrics by PEDOT:PSS Screen-Printing

“…Herein, PEDOT:PSS also changed WCA slightly, when it was combined with the SFXC binder, as in the case of Co. On the other hand, the inclusion of a WPU binder reduced WCAs to 110.3° ± 2.2°, 102.2° ± 3.5°, or 87.5° ± 4.2°, depending on the P:WPU ratio. This could be explained by the fact that, compared to conventional hydrophobic solvent-based polyurethanes, WPUs contain ionic groups and/or non-ionic hydrophilic segments (as perceived from the FTIR results in Figure 4 ) to disperse them in water [ 26 ]. Presumably, the hydrophilic groups of WPU on Co are oriented towards the fibres and hydrophobic outwards, leading to an increase of WCA, depending on WPU content.…”

The study of cationic waterborne polyurethanes modified by two different forms of polydimethylsiloxane

“…It has been shown that polydimethylsiloxane was successfully introduced into the cationic waterborne polyurethanes. [23][24][25]…”

Synthesis of Cationic Waterborne Polyurethanes from Waste Frying Oil as Antibacterial Film Coatings

“…However, cationic waterborne polyurethanes are seldom used commercially although they exhibit excellent adhesion properties to various anionic substrates and provide antimicrobial properties through interaction with bacterial cell membranes [12,[14][15][16]. Many studies have synthesized cationic waterborne polyurethanes by incorporating various internal emulsifiers into the polymer structures such as N-methyl diethanolamine [14][15][16][17][18] and quaternary ammonium groups [19][20][21] to increase the stability of hydrophobic polyurethane in the aqueous phase.…”