H_(12)MDI型水性聚氨酯胶膜力学性能研究

以二环己基甲烷二异氰酸酯(H12MDI)和聚醚或聚酯多元醇合成水性聚氨酯(WPU)乳液,通过对其胶膜力学性能测试及差示扫描量热法(DSC)分析,研究了合成配方及工艺条件对WPU胶膜力学性能的影响。结果表明,采用聚酯多元醇PCDL1000以及纯4,4′体的H12MDI为主要原料,合成乳液过程中提高二羟甲基丙酸(DMPA)用量和后扩链程度,以及采用分步投料均可提高WPU胶膜拉伸强度。     

不同结构的水性聚氨酯的合成及其性能研究

选用不同的软链段比例、不同的异氰酸酯比例和不同的扩链剂制备了水性聚氨酯(WPU),并讨论了n(-NCO)∶n(聚醚和聚酯中-OH)比值和R值的变化对WPU性能的影响。研究结果表明,在预聚反应中,当软链段中n(聚醚)∶n(聚酯)比值为0.5∶0.5、异氰酸酯中n(TDI)∶n(MDI)比值为0.5∶0.5、w(-COOH)为1.0%时,选用DEG为扩链剂、固定R值为1.3左右,可以得到性能优越的WPU。     

合成革用水性聚氨酯的制备

以异佛尔酮二异氰酸酯( IPDI),聚酯或聚醚多元醇、二羟甲基丙酸(DMPA)为主要原料,采用预聚体法合成了脂肪族革用水性聚氨酯(WPU),用三甲氧基三聚氰胺树脂(TMMM)对WPU进行交联反应成膜,考察了nNCO/nOH,DMPA用量、聚酯或聚醚种类以及TMMM对WPU性能的影响.结果表明,随着nNCO/nOH的增加...     

聚醚型与聚酯型聚氨酯弹性体的性能研究

使用聚乙二醇(PEG)、聚四亚甲基醚二醇(PTMG)、聚己内酯(PCL)和4,4’-二苯基甲烷二异氰酸酯(MDI)合成了聚醚多元醇型和聚酯多元醇型热塑性聚氨酯弹性体(TPU)。研究了各种TPU中异氰酸酯指数(R0)、硬段浓度(Ch)、聚醚和聚酯的种类、摩尔质量及原料用量等对弹性体力学性能的影响;并且使用双酚A型环氧树脂NPEL-127改性了弹性体的耐热性。研究结果表明:TPU的硬度随着R0和Ch的增加而增加;聚醚型TPU中,随着软段中柔性链的增加,TPU的硬度下降而力学性能提高;聚酯型TPU中,随着聚酯和聚酯二元醇摩尔质量的提高,TPU的硬度和力学性能均有提高;聚酯型TPU的力学性能优于聚醚型TPU;环氧树脂改性使得聚醚型TPU耐热性提高。     

基于磺酸盐的水性聚氨酯研究进展

用于水性聚氨酯(WPU)合成的磺酸盐包括小分子羟基磺酸盐、氨基磺酸盐以及含磺酸盐基团的聚醚和聚酯低聚物。小分子磺酸盐熔点高、脂溶性小,仅N-(2-氨基乙基)-氨基乙烷磺酸钠(AAS)在实际生产中得到应用,含磺酸盐基团的聚醚和聚酯低聚物作为WPU合成的亲水单体值得深入研究。     

扩链交联剂对水性聚氨酯乳液性能的影响

分别以一缩二乙二醇(DEG)、乙二醇(EG)、1,4-丁二醇(BDO)、乙二胺(EDA)及三羟甲基丙烷(TMP)为扩链交联剂,液化MDI为异氰酸酯组分,聚醚二醇(PPG)为低聚物多元醇组分,采用预聚体法制备了一系列水性聚氨酯(WPU)。通过万能材料试验机、热重分析(TG)、差示扫描量热仪(DSC)等表征手段研究了扩链交联剂对水性聚氨酯乳液及胶膜性能的影响。结果表明:BDO型WPU乳液粒径最小,黏度最大,稳定性最好;TMP型WPU胶膜具有最大拉伸强度,DEG型WPU胶膜具有最大断裂伸长率;TMP型WPU胶膜耐热性最好。     

反应型聚氨酯热熔胶粘剂的研制

以聚己二酸己二醇酯二醇(PHA)和聚醚多元醇(PPG)为软段,4,4’-二苯基甲烷二异氰酸酯(MDI)为硬段,制备了一系列聚酯／聚醚不同配比的反应型聚氨酯热熔胶。考察了各因素对反应型聚氨酯热熔胶粘接强度、固化速度等性能的影响。     

聚酯聚醚混合二元醇对水性聚氨酯性能的影响

以异佛尔酮二异氰酸酯(IPDI)和异佛尔酮二胺(IPDA)为硬段,分别以聚四氢呋喃二醇(PTMEG2000)、聚己二酸新戊二醇酯二醇(PNA2000)及其混合物为软段,制备了系列水性聚氨酯(WPU)乳液。通过ATR-FTIR对聚氨酯结构进行了表征分析,采用拉伸测试、热失重分析、动态力学分析及耐水性测试等手段对WPU胶膜性能进行了研究,探讨了不同软段结构对WPU胶膜性能的影响。结果表明:聚酯聚醚混合型水性聚氨酯的力学性能优于单一软段水性聚氨酯,其中PTMEG与PNA质量比为2∶1时力学性能最好;PTMEG型WPU胶膜的初始分解温度高于PNA型WPU胶膜,失重50%时分解温度相反;PTMEG型WPU胶膜的耐水性好于PNA型WPU胶膜。     

苯酐聚酯多元醇合成水性聚氨酯的研究

以苯酐聚酯二元醇(APP)为主要原料合成了水性聚氨酯(WPU)树脂,探讨了n(-NCO)/n(-OH)比值及扩链剂等对WPU成膜性能的影响。研究结果表明,适度交联可提高WPU胶膜的拉伸强度和耐水性;当w(二羟甲基丙酸)=3.3%、n(-NCO)/n(-OH)=4.0和w(乙二胺)=1.0%时,WPU胶膜的综合性能最好;与其他多元醇[如聚四氢呋喃多元醇(PTMEG)、聚醚多元醇(N-220)和聚酯多元醇(PS)等]合成的WPU树脂相比,用APP合成的WPU树脂,其成膜光泽和断裂伸长率较好、综合性能最优。     

高耐静水压水性聚氨酯的制备与表征

以液化MDI、聚四氢呋喃二醇(PTMG2000)、聚醚三元醇(N330)、二羟甲基丙酸(DMPA)等原料合成了交联型的高耐静水压水性聚氨酯(WPU),并用FT-IR、TG、DSC及耐静水压测试等手段对其结构和性能进行了表征。结果表明:N330的引入明显提高了WPU的耐静水压性能;当m(PTMG2000):m(N330)=5:1时,耐静水压性能最佳,乳液稳定且胶膜的综合性能优异。     

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 polyurethanes

A major change in coatings technology was caused by the restrictions on volatile organic compounds (VOC) in coatings. These government regulations combined with performance advantages were the key to the success of waterborne polyurethanes. The production and chemistry of waterborne one-component polyurethanes and reactive two-component systems are discussed. Examples for their application, predominantly in the field of surface coatings, are given.     

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.     

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.     

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.     

Effect of microstructural arrangement of MDI-based polyurethanes on their photoproperties

Among the vast variety of polyurethane applications, several applications use the fluorescing nature of some of the polyurethanes. Even though 4,4′-methylenebis(phenylisocyanate) (MDI)-based polyurethanes fluoresce, their applications are rare because of the lack of knowledge about the fluorescence behavior of these polymers. In this study, the fluorophores responsible for the emission spectra of MDI-based polyurethanes were identified, and their emission behavior was investigated. When excited, these polymers produce two prominent emission peaks located at 356 nm and 423 nm, which are assigned to the radiative relaxation of excited isolated hard segments and excited crystalline hard segment bundles of the MDI-based polyurethanes, respectively. It was found that both chromophores can be excited by 293 nm UV radiation. The observed intensity variations of the two peaks with exposure time were attributed to the localized UV melting-assisted migration of isolated hard segments. This migration facilitates the formation of crystalline hard segments. As the two chromophore populations are inversely propositional to each other, the relative intensity of the two emission peaks varies with UV exposure in a similar manner. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47431.     

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.     

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。