封闭异氰酸酯几种反应的动力学

封闭异氰酸酯广泛地应用于各种单组分涂料、粉末涂料和胶粘剂中。近年来,随着人们对水性聚氨酯的重视和开发,封闭异氰酸酯的重视和使用程度进一步加大。本文对封闭异氰酸酯的相关反应的动力学进行了综述,对两种不同的反应机理及其动力学的影响因素作了介绍。     

水性聚氨酯涂料改性研究进展

随着环保理念的日益增长,水性涂料将逐步取代溶剂型涂料.水性聚氨酯涂料由于其综合性能优越,是水性涂料中发展最快的品种之一,得到了广泛研究.为了进一步提高水性聚氨酯涂料的性能,通常要对聚氨酯树脂进行改性.对近些年常用的改性技术,如有机树脂改性、无机纳米材料改性和植物油改性的原理与方法进行了综述.这些改性技术可以提高水性聚氨酯的耐热性、耐水性、光泽度、物理机械性能、固含量等综合性能.     

单组分阴离子聚氨酯水乳液结构与性能

聚氨酯乳液;聚醚多元醇;二羟甲基丙酸;单组分阴离子聚氨酯水乳液结构与性能     

水性含氟聚氨酯的研究进展

水性含氟聚氨酯具有低的VOC排放,同时由于氟元素的引入,解决了传统水性聚氨酯耐水、耐油性差的缺点,大大拓展了其在涂料、皮革、油墨等领域的应用范围,因此受到广泛关注.本文综述了近年来国内外水性含氟聚氨酯的主要研究进展,综合比较了两种合成水性含氟聚氨酯主要方法,即核壳乳液聚合法和缩聚共聚法的各自特点,并对由两种不同方法制备的水性含氟聚氨的性能进行了讨论.     

软段含离子的含氟水性聚氨酯的制备

以单羟基氟碳链一元醇为有机氟改性剂,将含氟基团引入聚氨酯主链中,通过分子设计的方法制备出软段含有离子基团的有机氟阴离子型水性聚氨酯。 比较了传统水性聚氨酯、硬段含氟的水性聚氨酯和软段含氟的水性聚氨酯在合成方法、耐水性、 热稳定性以及结晶性方面的差异;实验证明了软段含氟聚氨酯的水性聚氨酯的性能最为优良。 通过红外光谱的表征确定了氟化聚氨酯的结构,并证明了含氟基团的引入对聚氨酯软硬段间氢键作用的影响;水接触角由73°增加至107°,吸水溶胀率降低了66%,胶膜耐水性提高;热重分析结果表明,含氟聚氨酯的最大热失重温度提高了30 ℃,热稳定性增加;广角X射线衍射结果表明,胶膜的结晶度增加,结晶形式发生了微小程度的转变;扫描电子显微镜结果证明存在不均匀的多相结构。     

蒙脱土硅氧烷双重改性水性聚氨酯

蒙脱土硅氧烷双重改性水性聚氨酯;水性聚氨酯;蒙脱土;硅烷偶联剂;乳液     

有机硅蒙脱土复合改性水性聚氨酯的研究

采用插层聚合制备了改性的水性聚氨酯乳液。X射线研究表明,蒙脱土以层间距5．19nm分散在水性聚氨酯基体中。硅烷和蒙脱土改性水性聚氨酯具有性能互补的效果,当有机蒙脱土和有机硅烷的质量分数分别为O．01及O．02时,聚氨酯乳液涂膜的拉伸强度和断裂伸长率比未改性时分别提高了70％、18％,吸水率降低了49％。     

环氧改性脂肪族水性聚氨酯的合成与性能

环氧改性脂肪族水性聚氨酯的合成与性能;环氧树脂;脂肪族水性聚氨酯;合成;性能     

聚甲基丙烯酸酯改性聚氨酯光固化水性体系研究

水性涂料;聚甲基丙烯酸酯改性聚氨酯光固化水性体系研究;接枝共聚物;聚氨酯丙烯酸酯;丙烯酸酯共聚物     

阳离子型水性聚氨酯制备和应用

阳离子型水性聚氨酯制备和应用台会文，王农跃，张留成（河北工学院化工系天津３００１３０）关键词聚氨酯，乳液，织物整理剂水性聚氨酯能赋予织物柔软、丰满的手感，改善织物耐磨性、抗皱性、防缩性、回弹性、通透性等。它还能与多种乳液树脂及助剂配合使用，是一类很有...     

Hydrogen bonding,mechanical properties,and surface morphology of clay/waterborne polyurethane nanocomposites

A novel clay/waterborne polyurethane (WPU) nanocomposite was synthesized from polyurethane and saponite organoclay. The clay was organically modified with various swelling agents, the effect of which has been investigated. Hydrogen bonding between organic and inorganic materials was characterized with Fourier transform infrared (FTIR) spectroscopy. The results implied that hydrogen bonding increased when organoclay was added. Mechanical and wear property studies revealed that introducing clay into waterborne polyurethane will enhance the Young's modulus (from 56 to 126 MPa), the maximum stress (from 3.9 to 7.6 MPa), and the elongation at break (from 27.7 to 58.7%) of the nanocomposite by a factor of two, whereas the wear loss will be only one third of the neat waterborne polyurethane. Atomic force microscopy (AFM) was used to analyze the surface morphology of the nanocomposite. An AFM microphotograph showed that the surface of the clay/waterborne polyurethane nanocomposite was smoother when clay was added in waterborne polyurethane. The average roughness (R_a) decreased from 1.00 to 0.12. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1–12, 2005     

应用于汽车修补的水性双组分聚氨酯涂料

回顾了汽车修补漆的历史,重点对应用于汽车修补漆的水性双组分聚氨酯涂料进行了综述,介绍了各种含羟基组分和异氰酸酯组分的组成、合成方法及其性能指标,指出该类涂料是一种非常具有发展前景的汽车修补漆。     

The Preparation and Properties of Polyurethane/Nano-CeO<Subscript>2</Subscript> Hybrid Aqueous Coating

To improve the ultraviolet resistance and thermal stability of waterborne polyurethane, stable waterborne polyurethane/nano-cerium oxide hybrid dispersions were obtained by adding nano-cerium colloids to previously synthesized waterborne polyurethane dispersions. The dried ceria colloid was characterized by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The XRD results indicated the prepared CeO₂ was a face-centered cubic structure. The prepared polyurethane/CeO₂ dispersions were studied by dynamic light scattering (DLS), transmission electron microscopy (TEM), UV–Vis spectroscopy and accelerated weathering test. The dried polyurethane/CeO₂ films were characterized using thermogravimetric analysis (TGA). The DLS analysis indicated the particles average diameter of hybrids emulsion was bigger than that of the pure waterborne polyurethane dispersion. TG analysis and accelerated weathering test suggested the hybrid latex films had better thermal stability and mechanical properties than those of the pure waterborne polyurethane. The UV–Vis absorption capacity of the dispersions prepared was increasing with the amount of CeO₂ colloid increased.     

紫外光固化水性树脂的研究与应用

介绍了紫外光固化水性树脂的分类,着重从引入的亲水基团种类的不同介绍了阴离子型、阳离子型以及非离子型三种水性UV固化自乳化型聚氨酯丙烯酸酯树脂的分类与制备,以及国内外的最新研究进展;并对水性UV固化聚氨酯丙烯酸酯树脂的其它相关研究进行了概述,简要介绍了水性UV固化树脂的相关应用.     

环氧改性水性聚氨酯乳液的制备及其膜性能

以聚己内酯二元醇(CAPA)为软段,异佛尔酮二异氰酸酯(IPDI)和六亚甲基二异氰酸酯(HDI)为硬段,环氧树脂E-44为大分子交联剂,经相转化法合成了一系列环氧树脂改性负离子水性聚氨酯(EPPU)自乳化乳液,并制备了改性水性聚氨酯的固化膜.通过FTIR、TGA及接触角、力学性能测试对聚合物结构及其膜性能进行了研究.通过原子力显微镜(AFM)观察膜表面形态和表面粗糙度.乳液粒径及粒径分布通过动态激光光散射法(DLLS)测定.FTIR分析表明环氧树脂的羟基和环氧基都参与了发应.TGA表明,环氧树脂的加入可以提高聚氨酯的热稳定性.随着w(E-44)增大,改性聚氨酯膜的拉伸强度得到改善,断裂伸长率减小.随着w(E-44)增大,乳液粒径增大,薄膜的接触角增大,改性后的PU膜表面光滑度下降,拒水性增强.     

水性紫外光固化树脂的研究进展

综述了近年来水性紫外光固化树脂及其涂料制备的最新研究进展.详细介绍了各类水性紫外光固化树脂的结构特点、制备方法及其在涂料中的应用情况,尤其对水性紫外光固化环氧树脂、聚氨酯树脂和超支化聚合物树脂等作了重点介绍,并展望了本领域的未来发展趋势.     

Tailoring the morphology and properties of waterborne polyurethanes by the procedure of cellulose nanocrystal incorporation

Polyurethane waterborne synthesis was performed using a two-step method, commonly referred to as a prepolymer method. Nanocomposites based on waterborne polyurethane and cellulose nanocrystals were prepared by the prepolymer method by altering the mode and step in which the nanofillers were incorporated during the polyurethane formation. The morphology, structural, thermal, and mechanical properties of the resulting nanocomposite films were evaluated by Fourier transform infrared spectroscopy (FTIR), small angle X-ray scattering (SAXS), scanning electron microscopy (SEM), and tensile tests. FTIR results indicated that the degree of interaction between the nanofillers and the WPU through hydrogen bonds could be controlled by the method of cellulose nanocrystal incorporation. Data obtained from SAXS experiments showed that the cellulose nanocrystals as well as the step of the reaction in which they are added influenced the morphology of the polyurethane. The reinforcing effect of CNCs on the nanocomposites depends on their morphology.     

Incorporation of Reactive Corrosion Inhibitor in Waterborne Acrylic Polyurethane Coatings and Evaluation of its Corrosion Performance

Hydroxyl-epoxy phosphate (HEP) as a reactive corrosion inhibitor was innovatively synthesized by the reaction of bisphenol A epoxy resin with phosphoric acid. HEP was mixed with hydroxyl acrylate resin, and crosslinked with waterborne isocyanate curing agent, which was used to form waterborne HEP/acrylic polyurethane composite (HEP-APU) coatings on Q235 steel surfaces. Electrochemical impedance spectroscopy and polarization curves were applied to analyze the corrosion behavior of the HEP-APU coatings in 3.5wt% NaCl solutions. The results indicated that the HEP-APU coatings show a superior passivation property and efficient corrosion protection of Q235 steel. The waterborne acrylic polyurethane coating containing 0.5wt% HEP exhibited the best corrosion performance among all the coating specimens. The improved flash-rust resistance can be attributed to the introduction of the phosphate group which could form phosphate film on the steel substrate.     

不完全相反转乳化过程分散相水滴形态发展研究

相反转乳化技术是制备高分子树脂水基分散体系的新方法[1～4].相反转指多组分体系(如油/水/乳化剂)中的连续相在一定条件下相互转化的过程,如在油/水/乳化剂体系中,其连续相由水相向油相(或从油相变为水相)的转变.在连续相转变区,体系的界面张力最低,因而分散相的尺寸最小.同理,可利用相反转技术直接将高分子树脂乳化为尺寸很小的水基微粒,即制备高分子树脂的水基分散体系.由于高分子树脂的粘弹性及相反转过程的复杂性,对高分子树脂的相反转乳化过程的机理研究较少.杨振忠[5]等通过调节高分子非离子型乳化剂浓度,可以有效地控制相反转完善程…     

海藻酸钠/水性聚氨酯共混膜的结构表征和性能测试

本文将海藻酸钠与聚酯型水性聚氨酯共混制膜，并通过红外光谱（FTIR）、X射线衍射（XRD）、扫描电镜（SEM）、紫外光谱（UV）、力学性能测试对共混膜的结构和性能进行了表征与测试。结果表明，共混膜中两种分子间存在着强烈的相互作用和良好的相容性，与纯海藻酸钠膜相比共混膜有较高的抗水性和断裂伸长率。