Preparation and properties of crosslinkable waterborne polyurethane and polyurethane-acrylic hybrid emulsions and their crosslinked polymers

Effect of chain extenders with different functionalities on the properties of single-component waterborne polyurethane ink binders

Waterborne polyurethane (WPU) dispersions were prepared by post-chain extension and crosslinking reactions using 2-[(2-aminoethyl)-amino]ethyl sulfonic acid sodium (AAS), diethylenetriamine (DETA), triethylenetetramine (TETA) and AAS/DETA as post-chain extenders, and their influence on the properties of WPUs was studied. Results showed the introduction of trifunctional DETA chain extenders significantly improved the molecular weight, T-peel strength, and water resistance of WPUs, suggesting that DETA was an effective crosslinking agent. The WPU dispersions with a 2 : 3 molar ratio of AAS/DETA chain extenders exhibited excellent properties. At a molar ratio of 1.6 for NCO groups to OH groups, a stable WPU dispersion possessed higher solid content of 42.8%. Furthermore, only 4 wt% organic solvents were used in the preparation of WPU dispersions. Results revealed that the obtained WPU dispersions are a potential candidate for binders in water-based inks, without removing organic solvents. This study may provide some insight or guidance for the design and preparation of water-based ink binders.

Waterborne polyurethane (WPU) dispersions were prepared by post-chain extension and crosslinking reactions using different functional chain extenders. The influences of chain extenders type on the properties of WPUs were investigated.

Predicted Studies of Branched and Cross-Linked Polyurethanes Based on Polyhydroxybutyrate with Polycaprolactone Triol in Soft Segments

The number of cross-links in the non-linear polyurethane structure is the basic factor affecting its properties. Selected properties of aliphatic polyurethanes with soft segments made of different amounts of polycaprolactonetriol, polycaprolactonediol and synthetic, telechelic poly([R,S]-3-hydroxybutyrate) were determined. On the basis of changes in polyurethane properties, the correlation between these properties and the construction of soft segments was found. The structure of polyurethanes, their morphology, hydrophilicity, thermal and mechanical properties were examined. These properties were changed linearly up to 15% content of polycaprolactonetriol in soft segments. A further increase in the amount of triol causes that these properties are mainly determined by the high number of cross-links.

Preparation and Characterization of Soybean Oil-Based Polyurethanes for Digital Doming Applications

Polyurethane-resin doming is currently one of the fastest growing markets in the field of industrial graphics and product identification. Semi-rigid bio-based polyurethanes were prepared deriving from soybean oil as a valuable alternative to fossil materials for digital doming and applied to digital mosaic technology. Bio-resins produced can favorably compete with the analogous fossil polymers, giving high-quality surface coatings (ascertained by SEM analyses). In addition, polyurethane synthesis was accomplished by using a mercury- and tin-free catalyst (the commercially available zinc derivative K22) bringing significant benefits in terms of cost efficiency and eco-sustainability.