Performance Of Waterborne Polyurethane Research Articles

Preparation and properties of water‐borne polyurethane‐sodium lignosulfonate/nano‐calcium carbonate composites

AbstractTo improve the application range of waterborne polyurethane (WPU), in this study, nano calcium carbonate/sodium lignosulfonate (CaCO3/SL) composites were prepared using sodium lignosulfonate (SL) wet‐modified calcium carbonate nanoparticles. Then, a series of waterborne polyurethane (WPU) nanocomposites (WPU‐CaCO3/SL) were prepared by solution mixing. Zeta, FT‐IR, XRD, SEM, and TGA were used to characterize the structure and morphology of CaCO3/SL and WPU‐CaCO3/SL. By conducting an analysis on the impact of various dosages of CaCO3/SL composite on the performance of WPU, the findings revealed that the tensile strength of WPU‐CaCO3/SL nanocomposites, when composed with a 3 wt% CaCO3/SL dosage, exhibited a significant increase of 116% from 6.93 to 14.95 mPa. The water contact angle demonstrated a significant increase from 78.3° to 90.1°. Additionally, the maximum decomposition temperature showed a noticeable rise of approximately 7°C. The WPU exhibit enhanced heat resistance, water resistance and mechanical properties, as well as exceptional ultraviolet (UV) absorption capabilities. This study provides a reference for modifying polymers with inorganic fillers and improving the optical properties of polymeric materials.Highlights Successful modification of nano calcium carbonate using biopolymer SL. Modified CaCO3/SL can be uniformly dispersed in water. Improved thermal stability of WPU composites. WPU composites exhibit excellent mechanical properties and water resistance. Well‐dispersed CaCO3/SL improves ultraviolet radiation resistance of WPU composites.

Synthesis and self‐healing investigation of waterborne polyurethane based on reversible covalent bond

AbstractA series of self‐healing waterborne polyurethane (WPU) films utilizing reversible covalent bond acylhydrazones diol (PA) as chain extender were successfully synthesized. The self‐healing performance of WPU with different content of chain extender PA has been systemically characterized via cut‐and‐healing tests and mechanical quantitative evaluation. The film can repair cracks through acylhydrazone exchange reactions within 12 h. When the content of PA is 1.5 wt%, the WPU has the highest self‐healing efficiency of 90.5%. Meanwhile, the effect of PA mass fraction on the particle size distribution, mechanical ability, crystallization, water resistance properties, and thermal stability of WPU were evaluated. With the introduction of acylhydrazone bonds, the hydrophobicity of the WPU material was enhanced, while achieving self‐healing performance, which solves the problem of aging and replacement of materials. These results indicated that the self‐healing WPU exhibited great application prospect as a versatile material.

Performance of Waterborne Polyurethanes in Inhibition of Gas Hydrate Formation and Corrosion: Influence of Hydrophobic Fragments.

The design of new dual-function inhibitors simultaneously preventing hydrate formation and corrosion is a relevant issue for the oil and gas industry. The structure-property relationship for a promising class of hybrid inhibitors based on waterborne polyurethanes (WPU) was studied in this work. Variation of diethanolamines differing in the size and branching of N-substituents (methyl, n-butyl, and tert-butyl), as well as the amount of these groups, allowed the structure of polymer molecules to be preset during their synthesis. To assess the hydrate and corrosion inhibition efficiency of developed reagents pressurized rocking cells, electrochemistry and weight-loss techniques were used. A distinct effect of these variables altering the hydrophobicity of obtained compounds on their target properties was revealed. Polymers with increased content of diethanolamine fragments with n- or tert-butyl as N-substituent (WPU-6 and WPU-7, respectively) worked as dual-function inhibitors, showing nearly the same efficiency as commercial ones at low concentration (0.25 wt%), with the branched one (tert-butyl; WPU-7) turning out to be more effective as a corrosion inhibitor. Commercial kinetic hydrate inhibitor Luvicap 55 W and corrosion inhibitor Armohib CI-28 were taken as reference samples. Preliminary study reveals that WPU-6 and WPU-7 polyurethanes as well as Luvicap 55 W are all poorly biodegradable compounds; BODt/CODcr (ratio of Biochemical oxygen demand and Chemical oxygen demand) value is 0.234 and 0.294 for WPU-6 and WPU-7, respectively, compared to 0.251 for commercial kinetic hydrate inhibitor Luvicap 55 W. Since the obtained polyurethanes have a bifunctional effect and operate at low enough concentrations, their employment is expected to reduce both operating costs and environmental impact.

Facile preparation of homogenous waterborne poly(urethane/acrylate) composites and the correlation between microstructure and improved properties

AbstractHomogenous waterborne polyurethane/polyacrylate emulsions were synthesized based on the prepared polyurethane and polyacrylate through a facile process. The attention was attracted to the miscibility and performance of waterborne polyurethane and polyacrylate. The structures and properties of waterborne polyurethane and waterborne polyurethane/polyacrylate samples were characterized by using Fourier transform infrared spectroscopy, transmission electron microscope, X‐ray photoelectron spectroscopy, X‐ray diffractometer, thermogravimetric, and so forth, as well as solid content and tensile testing. The results showed that the micro morphology of waterborne polyurethane/polyacrylate emulsion presented single‐phase structure with the stoichiometric polyacrylate content increasing from 33% to 80% to waterborne polyurethane. The waterborne polyurethane/polyacrylate films surface is rich in polyacrylate phase. Meanwhile, waterborne polyurethane/polyacrylate composites showed significant improvement in thermal stability and elongation at break, smaller particle size and narrower particle size distribution comparing with waterborne polyurethane.

Preparation and Performance Optimization of Two-Component Waterborne Polyurethane Locomotive Coating

This paper reports the effects of different formulas on the performance of waterborne polyurethane (WPU), including two-component WPU and curing agent, wetting dispersant, defoaming agent, and wetting agent. The optimization of rheological additives selection, through the optimization of coating physical properties and chemical properties, can make the film show uniform color and appearance without pinholes, bubbles, or wrinkles, and have a long probation period. Through the analysis of performance after a 1000-h quick ultraviolet (QUV) aging test, the light reduction rate is 23.19%, and the color difference is 1.9. As can be seen from the scanning electron microscope (SEM) image and the three-dimensional stereomicroscope, the film shows relatively uniform dispersion, good compactness, and smooth surface. The two-component WPU topcoat is found to have high gloss 87.1 (60°) and high weather resistance, which provides a positive indication for the modulation and production of waterborne locomotive paint.

Preparation and properties of novel ultraviolet-cured waterborne polyurethanes

A new ultraviolet (UV)-cured waterborne polyurethane (WPU) mainly composed of ionic soft segments, imide groups, and a new water-soluble UV-cured cross-linking agent containing both C=C bond and carboxy group was prepared. The ionic soft segments were prepared by 1,6-hexamethylene diisocyanate , poly(propylene glycol)-600, and dimethylol butanoic acid. The imide groups were introduced into polyurethane by extending them with pyromellitic dianhydride (PMDA). The new water-soluble UV-cured cross-linking agent (MLGLY) was synthesized by hydrophilic maleic anhydride and glycerol oligomer. The particle size and the viscosity of the new anionic WPU as well as the water swelling, gel content, mechanical properties, and thermal stability of the UV-cured WPU cast films were investigated. The results showed that the best performance of WPU was obtained with 0.024 mol of PMDA and 5 wt% of MLGLY.

Improved Water Resistance of Waterborne Polyurethane

The introduction of hydrophilic groups, such as -COOH, -SO3, -OH, -O-, into the polyurethane resin, so that waterborne polyurethane products in the water resistance, solvent resistance, weather and other aspects of performance are worse than solvent borne systems. In our work, to improve the water resistance of the films for waterborne polyurethane, we incorporated C=C bond into the side chain of polyurethane by using pentaerythritol diacrylate as an extension agent. By measuring the cured polyurethane films absorption and mechanical properties, we determine the conditions for UV curing, 3% TMPME, photoinitiator (2959) and to UV light application time for 30s. With the increase of the amount PEDA, water resistance, hardness and tensile strength increase. Furthermore, with the improved water resistance, it is hoped that the performance of waterborne polyurethane can be comparative or superior to the solvent-borne systems.