MDI型水性聚氨酯涂料的研究进展

综述了二苯基甲烷二异氰酸酯(MDI)与聚醚型、聚酯型或聚醚-聚酯共混型多元醇反应制备的水性聚氨酯(WPU)涂料的研究进展,简单介绍了MDI型WPU涂料在不同领域的应用,并对MDI型WPU涂料的未来发展前景作了展望.     

水性功能型聚氨酯的研究进展

综述了水性功能型聚氨酯的研究进展,主要包括功能型水性聚氨酯涂料、功能型水性聚氨酯胶粘剂以及其他功能型水性聚氨酯。对水性功能型聚氨酯的发展前景作了展望。     

Waterborne two-pack isocyanate-free systems for industrial coatings

Two-pack paint systems are used in various segments of the industrial coatings market. Stringent legislation concerning the emissions of organic solvents has led to an increasing demand for green alternatives, for the current solventborne products. Water, in this respect, is one of the most interesting technologies for ambient curing systems. A novel waterborne isocyanate-free two-pack system for high gloss topcoats is herewith described. The system is based on two waterborne acrylics with different functional groups. Properties of the system were compared with the performance of waterborne two-pack polyurethanes based on polyisocyanates and waterborne acrylic polyols. Solventborne versions of both two-pack systems were also used as references.     

Waterborne polyurethane dispersions obtained with polycarbonate of hexanediol intended for use as coatings

Three waterborne polyurethane dispersions derived from polycarbonate of hexanediol (PCD) with molecular weight of 1000 Da were synthesized by the acetone method and used as coatings for stainless steel plates. Different hard segments content in the polyurethanes were obtained by varying the isocyanate/macroglycol (NCO/OH) molar ratio. A decrease in the NCO/OH ratio produced an increase in the mean particle size as well as a decrease in the Brookfield viscosity of the dispersions. Furthermore, the greater the NCO/OH ratio the higher the urea and urethane hard segment content, the higher the glass transition temperature value and the higher the elastic modulus of the polyurethane was. On the other hand, the NCO/OH ratio affected the adhesion of the polyurethanes. The adhesion was evaluated by using three different procedures: T-peel strength tests of flexible PVC/waterborne polyurethane dispersion/flexible PVC joints; single lap-shear tests of aluminium/waterborne polyurethane dispersion/aluminium joints and cross-cutter adhesion test of polyurethane coatings on stainless steel pieces. Finally, several properties of the polyurethane coatings on stainless steel pieces were tested including Persoz hardness, gloss, chemical resistance and yellowness index.     

Design and synthesis of antibacterial waterborne fluorinated polyurethane

Antibacterial waterborne polyurethanes (WPUs) have attracted increasing attention in a wide range of industrial applications because of their versatile properties as well as ecofriendly nature. Although extensive research has been carried out on antibacterial WBPU synthesis, the roles of some of the key synthesis components remain unclear. In this study, the novel chain extender DMG (dimethylol propionamide containing guanidine group) was designed and synthesized, which has not been reported before. DMG and the waterborne fluorinated polyurethanes containing DMG show high bactericidal (> 99.99%) efficacy against a broad spectrum of gram-positive and gram-negative bacteria. Furthermore, when the amount of DMG reached 5%, the average particle size of waterborne fluorinated polyurethane dispersions was 56.24 nm. And waterborne fluorinated polyurethanes showed good thermal (> 460 °C) properties and high crystallization with the increase of chain extender DMG. The successful synthesis of these fascinating antibacterial waterborne materials may provide new insights into the development of protection materials in a sustainable form, which could be applied as coatings in various fields to prevent microbial contamination. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46923.     

功能型水性聚氨酯涂料的设计与应用最新进展

水性聚氨酯由于分子中引入了亲水基团,使其在耐水性、耐溶剂性、耐候性、干燥速度等方面表现欠佳,需要不断对其进行改性研究,如有机硅氟改性、环氧改性、纳米复合等。综述了近几年水性聚氨酯涂料的功能化设计、合成技术与应用进展,主要包括具有阻燃、防腐蚀、防霉杀菌、防涂鸦、透明隔热等特殊性能的功能型水性聚氨酯涂料的设计方法及应用实例。并对功能型水性聚氨酯涂料的未来发展前景作了展望,指出了功能性水性聚氨酯涂料的功能化设计方向。     

水性聚氨酯及其在纺织助剂中的应用

本文对聚氨酯的基本原料及水性聚氨酯改性作了详细阐述,以便水性聚氨酯的推广应用。     

Preparation of waterborne polyurethanes using an amphiphilic diol for breathable waterproof textile coatings

The application of polyurethanes (PUs) on breathable waterproof fabric coatings requires a balance of water vapor permeability (WVP) and water resistance which can be achieved by tailoring hydrophilic and hydrophobic segments. PU prepolymers were prepared from isophorone diisocyanate, dimethylol butanoic acid, and a mixture of various ratios of amphiphilic PPG2050 (copolymer of ethylene oxide and propylene oxide with –OH end groups) and hydrophobic poly(tetramethylene ether glycol) (PTMEG). After neutralization with triethylamine, the prepolymers were chain-extended with ethylene diamine/1,4-butanediol (1:1 by molar). The WVP values of the fabric coatings prepared using various waterborne PUs were very similar (910–990 g/m² × 24 h). When waterborne PUs prepared using a mixture of PPG2050 and PTMEG were employed for the textile coatings, the resulting PU-coated textiles exhibited excellent waterproof properties (>10,000 mm H₂O). The textile coatings prepared from PPG2050/PTMEG-based waterborne PUs were significantly more waterproof than those prepared from poly(ethylene glycol) (PEG)/poly(propylene glycol) (PPG)/PTMEG-based waterborne PU. This is probably due to a more even distribution of hydrophobic segments in the PUs, even though the WVP values of the PEG/PPG/PTMEG-based PU coatings were considerably smaller than those of the PPG2050/PTMEG-based PU coatings.     

Incidence of the polyol nature in waterborne polyurethane dispersions on their performance as coatings on stainless steel

Three waterborne polyurethane dispersions derived from polyester, polyether and polycarbonate diols with molecular weight of 1000 Da were synthesized by the acetone method and used as coatings on stainless steel 304 plates. The properties of the dispersions and the polyurethane films were influenced by the polyol nature. The polyurethanes obtained with polyether or polyester showed higher degree of phase separation between the soft and the hard segment. The higher adhesive strength under shear stresses was obtained in the joints produced with the waterborne dispersion obtained with polycarbonate diol. The properties of the polyurethane coating obtained with polycarbonate diol on stainless steel 304 were significantly higher as compared with the others. Improved performance of coatings obtained with polycarbonate diol was ascribed to the higher polarity of the carbonate groups that contributed to additional hydrogen bond formation between soft segments with respect to those obtained with polyether or polyester     

Recent trends in environmentally friendly water-borne polyurethane coatings: A review

Environmentally friendly waterborne polyurethane (WPU) coatings are used extensively due to their low VOCs emission than solvent based PU coatings. Additionally, WPU coatings have low temperature flexibility, pH stability, water resistance, superior solvent resistance, outstanding weathering resistance and desirable chemical and mechanical properties. This review provides an overview on the recent developments of WPU coatings and their value added applications in the coatings and paint industry. UV-cured WPU coatings provide an important class of green and ecofriendly coatings with outstanding mechanical properties and rapid curing system. Hyper-branched polyurethanes (PUs) show interesting properties, such as high solubility, reactivity and good rheological behavior owing to multiple end groups, compact molecular structure and diminishing chain entanglement. Inherently, WPU coatings have reduced stiffness and mechanical strength that can be increased by the addition of nanoparticles, like Ag, Cu, TiO₂, SiO₂ and many more. Fire retardants, commonly phosphorous, are incorporated in the WPU structure to increase the flame retardancy of WPU coatings.     

环氧树脂改性水性聚氨酯的研究

通过自乳化法合成了水性聚氨酯,用环氧树脂E-44改性水性聚氨酯。探讨了水性聚氨酯的配方及反应条件,研究了环氧树脂用量、加入方式、温度等因素对乳液稳定性和涂膜性能的影响。结果表明：用环氧树脂改性水性聚氨酯,可显著提高水性聚氨酯的耐水性、耐溶剂性等性能。     

Preparation of waterborne polyurethanes using an amphiphilic diol for breathable waterproof textile coatings

The application of polyurethanes (PUs) on breathable waterproof fabric coatings requires a balance of water vapor permeability (WVP) and water resistance which can be achieved by tailoring hydrophilic and hydrophobic segments. PU prepolymers were prepared from isophorone diisocyanate, dimethylol butanoic acid, and a mixture of various ratios of amphiphilic PPG2050 (copolymer of ethylene oxide and propylene oxide with –OH end groups) and hydrophobic poly(tetramethylene ether glycol) (PTMEG). After neutralization with triethylamine, the prepolymers were chain-extended with ethylene diamine/1,4-butanediol (1:1 by molar). The WVP values of the fabric coatings prepared using various waterborne PUs were very similar (910–990 g/m² × 24 h). When waterborne PUs prepared using a mixture of PPG2050 and PTMEG were employed for the textile coatings, the resulting PU-coated textiles exhibited excellent waterproof properties (>10,000 mm H₂O). The textile coatings prepared from PPG2050/PTMEG-based waterborne PUs were significantly more waterproof than those prepared from poly(ethylene glycol) (PEG)/poly(propylene glycol) (PPG)/PTMEG-based waterborne PU. This is probably due to a more even distribution of hydrophobic segments in the PUs, even though the WVP values of the PEG/PPG/PTMEG-based PU coatings were considerably smaller than those of the PPG2050/PTMEG-based PU coatings.     

纳米材料在改性水性聚氨酯中的应用（Ⅰ）

本文介绍了纳米材料改性水性聚氨酯的制备方法,综述了纳米二氧化硅、纳米二氧化钛、纳米蒙脱土和纳米聚多糖对水性聚氨酯改性的研究进展,并对该类涂料的发展趋势和应用前景进行了展望。     

Synthesis of polymeric dyes based on self-colored network of castor oil-based waterborne polyurethane

The development of vegetable oil-based polymers was particularly suitable for the era of increasingly scarce petroleum. Self-colored castor oil-based waterborne polyurethanes (PUs) were successfully synthesized based on castor oil and 1-amino-4-hydroxy-2-(6-hydroxyhexyl) anthraquinone (DR) as polyols. The UV–Vis spectrum showed that the addition of carboxylic acid groups make the spectrum of the PU produce the hyperchromic effect under alkaline conditions. Castor oil-based waterborne colored PUs possessed excellent stability under weak alkaline conditions. The connection of castor oil caused the PU to constitute soft polymer networks. PU coatings on cotton fabrics possessed excellent color properties. The urethane groups in the PUs formed hydrogen bonds with the hydroxyl groups on the cotton fibers and the polymer network structure formed by the PU coating itself made the color fastness of the cotton coatings reached grade 5. With the increase of castor oil content, the degradation rate of castor oil-based waterborne colored PU increased from 3.45% to 3.65%. This work provides a way to impart excellent color properties and fastness to PU coatings by inserting dye molecules and vegetable oils into the PU macromolecular chain.     

The Thermal Degradation of Waterborne Polyurethanes with Catalysts of Different Selectivity

The thermal stability of waterborne polyurethanes was measured by use of the thermogravimetric analysis. Waterborne polyurethanes (wbPUR) with catalysts of different selectivity were characterized using dynamic heating. In the dynamic method, heating rates with increments of 0.5, 1, 2, 5, and 10°C min^?1 were used in the range of 30–500°C, to achieve degradations of 0.025, 0.05, and 0.10, respectively. By using more selective catalysts, the resulting total time of decomposition was increased in all cases of degradation degrees for given initial temperature of waterborne polyurethanes. This paper shows how the dynamic method based on thermogravimetric analysis can be used to calculate the thermal stabilities of waterborne polyurethanes, using catalysts of different selectivity.     

松香基聚氨酯的研究进展

综述了近年来松香在溶剂型聚氨酯、水性聚氨酯、无溶剂型聚氨酯和非异氰酸酯型聚氨酯4个方面的改性方法,发现松香及其衍生物既能有效减少合成溶剂型聚氨酯所需石化原料的用量,还可提高环保型聚氨酯的耐水性能、热力学性能和机械性能,但是仍存在改性聚氨酯手段单一、松香基多元醇相对分子质量较小、反应条件苛刻、应用还不广泛等问题,并对松香改性聚氨酯的发展趋势和研究方向做出展望。     

防水透湿型水性聚氨酯织物涂层的研究进展

根据防水透湿型水性聚氨酯是否对温度敏感进行分类,通过列举一些新方法,总结了近年来国内外学者在防水透湿型水性聚氨酯涂层方面的研究进展,展望了防水透湿型水性聚氨酯织物涂层未来的发展方向。     

水性涂料在混凝土防腐中的应用

随着水性涂料的不断发展和成熟,混凝土防腐用水性涂料体系也不断涌现。结合交通行业中混凝土桥梁防腐涂料标准及防腐技术条件,以及具体的涂料使用环境和工程实践,介绍了水性环氧类混凝土防腐涂料体系、水性丙烯酸类混凝土防腐涂料体系、清水混凝土用水性氟硅透明涂料体系等三类目前使用较为广泛的混凝土防腐用水性涂料体系及其各自特点。     

水性重防腐涂料的研究进展

概括了几种水性重防腐涂料所用的树脂及其研究进展,重点综述了水性环氧重防腐涂料和水性无机硅酸锌涂料的发展状况。其次,讨论了几种应用于水性重防腐涂料的防锈颜料和鳞片状填料,特别是对于玻璃鳞片进行了比较详细和深入的分析。最后,对于水性重防腐涂料未来的发展方向提出了展望。     

紧固件防护涂层的制备及耐蚀性能研究

阐述了水性含氟涂层和水性纳米铝粉环氧涂层的配方及固化工艺研究,制备用于紧固件腐蚀防护的水性有机涂层。使用DSC对涂层的工艺进行了优化,使用SEM对涂层表面形貌进行了表征。利用电化学阻抗谱(EIS)对两种涂层的耐腐蚀性能进行了研究,结果表明:制备出的含氟涂层致密孔隙少,耐腐蚀性能明显优于水性纳米复合涂层。