Fluorinated siloxane-containing waterborne polyurethaneureas with excellent hemocompatibility, waterproof and mechanical properties

Hydroxyl-Terminated Polybutadiene-Based Polyurethane with Self-Healing and Reprocessing Capabilities

Hydroxyl-terminated polybutadiene (HTPB)-based polyurethane (PU) networks play indispensable roles in a variety of applications; however, they cannot be reprocessed, resulting in environmental problems and unsustainable industrial development. In this work, recyclable HTPB-based PU vitrimer (HTPB-PUV) networks are fabricated by introduction of a cross-linker 2,2'-(1,4-phenylene)-bis[4-mercaptan-1,3,2-dioxaborolane] (BDB) with dynamic boronic ester bonds into the network. Meanwhile, the BDB can stabilize the HTPB unit in the network by elimination of double bonds. The novel HTPB-PUV networks are constructed by a thiol-ene "click" reaction and an addition reaction between HTPB and cross-linker BDB and isocyanates (HDI). The dynamic HTPB-PUV networks are characterized by dynamic mechanical analysis (DMA) and Fourier transform infrared (FTIR). The obtained dynamic HTPB-PUV networks possess superior thermostability. Moreover, due to the presence of dynamic boronic ester bonds, the HTPB-PUV network topologies can be altered, contributing to the reprocessing, self-healing, and welding abilities of the final polymer. Through a hot press, the pulverized sample can be reprocessed for several cycles, and mechanical properties of the reprocessed samples are similar to those of the pristine one, with the tensile strength being even higher. The self-healed sample exhibits almost complete recovery from scratch after the healing treatment at 130 °C for 3 h. Moreover, a welding efficiency of 120% was achieved.

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.

Synthetic scheme to improve the solid content of biodegradable waterborne polyurethane by changing the association relationships of hydrophilic fragments

A synthetic method was developed to prepare biodegradable waterborne polyurethanes (BHPUs) with a high solid content by introducing different molecular weights of poly(ethylene glycol) (PEG) into poly(ε-caprolactone) (PCL)-based polyurethanes. PCL is a semi-crystalline polymer that can be degraded in lipase to prepare biodegradable waterborne polyurethanes. The biodegradability of BHPUs was evaluated, and the results showed that BHPU samples could be degraded in a solution of phosphate-buffered saline (PBS)/lipase but not in PBS. Two different synthesis routes were used to prepare the BHPUs, which resulted in different association relationships between the ionic hydrophilic polymer dimethylol propionic acid (DMPA) and a nonionic hydrophilic polymer (PEG). The influence of the association relationship between DMPA and PEG on the solid content and other BHPU properties was investigated. The results showed that the method of associating all PEG molecules with DMPA increased the crystallization, tensile properties, and water and soil repellency of the BHPU samples. The solid content of the BHPU samples increased from 41% to 52.7%. In addition, PEG with molecular weights of 400 g mol⁻¹ and 1000 g mol⁻¹ had the best effect on the dispersibility and stability of BHPU samples when incorporated into a polyurethane backbone.

A synthetic method was developed to prepare biodegradable waterborne polyurethanes (BHPUs) with a high solid content by introducing different molecular weights of poly(ethylene glycol) (PEG) into poly(ε-caprolactone) (PCL)-based polyurethanes.

Mechanically robust and tough waterborne polyurethane films based on diselenide bonds and dual H-bonding interactions with fast visible-light-triggered room-temperature self-healability

A dynamic but mechanically robust and tough polymer network was proposed, in which the fast room-temperature self-healing of our target polymer with mechanically robust and tough features is achieved under visible light.

Tailoring elastomeric properties of waterborne polyurethane by incorporation of polymethyl methacrylate with nanostructural heterogeneity

Nanostructural heterogeneous hybrid materials of waterborne polyurethane acrylate were prepared by a two-step procedure. The elastomeric properties of WPUA can be tailored by incorporated content of polymethyl methacrylate.

Crosslinked waterborne polyurethane with high waterproof performance

Fluorinated acrylate and siloxane waterborne polyurethanes with crosslinked structure exhibit low water absorption, high water contact angles, and high mechanical/thermal properties.

Preparation and application of fluorinated-siloxane protective surface coating material for stone inscriptions

A series of fluorinated-siloxane protective surface coating materials (FPA/SiO2) were prepared with different contents of dodecafluoroheptyl methacrylate (DFMA) and fixed content of siloxane. The properties of FPA/SiO2 protective materials were investigated by the methods of Fourier transform infrared spectroscopy (FT-IR) spectra, UV-Vis spectrum, transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The surface morphology and mineralogical analysis of the fresh and weathered stone samples were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The artificial ageing test, which was commonly used as a criterion for the evaluation of the protective ability of FPA/SiO2 coating material, was performed. The results indicate that when the content of DFMA is 30 wt.% and the content of SiO2 is 10 wt.%, the prepared coating material has good comprehensive performances. The artificial ageing test shows that the protective surface coating material has good compatibility with and similar appearance to stone relics. The effect of FPA/SiO2 protective coating material for protection of Jiaoshan Steles Grove (China) is noticeable and it can be widely applied to the protection of stone relics.