Coatings prepared from waterborne polyurethane dispersions obtained with polycarbonates of 1,6-hexanediol of different molecular weights

Waterborne polyurethane dispersions (PUDs) were synthesized with polycarbonates of 1,6-hexanediol of different molecular weight (500–3000 Da) and their properties, adhesion (Hatch adhesion) and coatings on stainless steel properties (Pencil hardness, Persoz hardness, gloss at 60°, chemical resistance, yellowness index) were characterized. The hatch adhesion of the polyurethane coatings to stainless steel was very good and decreased slightly by increasing the molecular weight of the polycarbonate of 1,6-hexanediol. Both the Pencil and Persoz hardness values of the coatings increased by increasing the hard segments content in the polyurethane, i.e. by decreasing the molecular weight of the polycarbonate of 1,6-hexanediol, whereas the gloss and the yellowness index were lower for the coatings obtained with the polycarbonate of 1,6-hexanediol of molecular weight of 500 Da. Very good chemical resistance against ethanol for all polyurethane coatings on stainless steel plates was obtained but for long time of ethanol in contact with the coating surface the chemical resistance decreased, more markedly for the polyurethane coating obtained with the polycarbonate of 1,6-hexanediol of higher molecular weight. In summary, the segmented structure of the waterborne polyurethane dispersion determined the properties of the polyurethane coatings obtained from them.     

Effects of Nanoparticles on Film Properties of Waterborne Acrylic Emulsions

Waterborne acrylic emulsion was obtained by using methyl methacrylate, ethyl and butyl acrylate monomers. Emulsions containing nanoparticles were prepared by blending the stable dispersions containing SiO₂ or MMT nanoparticles. The films were prepared from emulsions and coating tests were applied. The physical properties of prepared emulsions are better than the commercial emulsions. The addition of the nanoparticles especially SiO₂ have positive effect on the resistance to environmental conditions of emulsions. Waterborne acrylic emulsions containing nanoparticles prepared in this study can be used in the manufacturing of the semi-lustrous emulsion type nano paint with low cost, high performance and environmentally friendly.     

Preparation,Morphology and Properties of Waterborne-Polyurethane/Silica

A series of waterborne-polyurethane/silica (WPU/SiO₂) were prepared from isophoronediisocyanate, polyester polyol, dimethylolpropionic acid, tetraethoxysilane and 3-glycidyloxypropyl trimethoxysilane. The WPU/SiO₂ dispersion had narrower particle size distribution than the pure WPU. The mechanical properties of WPU/SiO₂ films were improved than the pure WPU. WPU/SiO₂ films were characterized by FT-IR spectroscopy, SEM, TEM, AFM, XRD and UV-Vis spectroscopy. The results showed that WPU/ SiO₂ hybrid films were found to be smooth morphology, and had good thermal stability and tunable transparence with the silica fraction in the film. Through suitable adjustment of silica content, some thin films have potential applications as the specialty materials.     

聚酯型热致形状记忆水性聚氨酯的制备与性能研究

采用聚己二酸丁二醇酯(PBA)、异佛尔酮二异氰酸酯(IPDI)、二羟甲基丙酸(DMPA)、三乙胺(TEA)、乙二胺(EDA)等单体,通过自乳化法合成了聚酯型热致形状记忆水性聚氨酯(TSMWPU)。利用偏光显微镜(POM)、差示扫描量热仪(DSC)、动态黏弹谱仪(DMA)和形状记忆性能分析等手段,探讨了不同分子量的PBA,以及不同异氰酸酯基与羟基的摩尔比(NCO/OH)对TSMWPU的结晶性能和形状记忆性能的影响。结果表明;增加PBA分子量,有利于软段结晶,从而提高TSMWPU的形状记忆性能;而增加NCO/OH值,则抑制了软段结晶,进而导致TSMWPU的形状记忆性能下降。     

Ⅰ型水性环氧树脂涂料的研制

采用低分子量液体环氧树脂与非离子表面活性剂（BMJ）反应合成BMJ－环氧加成物,将表面活性链段引入到环氧树脂分子链中,然后经封端和成盐得到Ⅰ型水性环氧固化剂,研究了影响Ⅰ型水性环氧固化剂及其所配乳液涂料性能的因素,并对乳液的稳定性和固化速度,漆膜硬度等性能进行了评价。     

水基环氧树脂乳液及其胶粘剂

概述了环氧树脂乳液的发展及制造方法;介绍了以环氧树脂乳液为基础的胶粘剂配方及基本性能;重点讨论了单组分环氧乳液作为胶粘剂在建筑领域的应用。     

环氧树脂基双组分水性聚氨酯的制备及其在木器涂料中的应用

为提高双组分水性聚氨酯的室温交联速度,将N-苄基乙醇胺引入到环氧树脂制备了环氧树脂基水性多元醇,表征了多元醇的化学结构,并测定了其相对分子质量、粒径分布和玻璃化温度等主要技术参数。将环氧树脂基水性多元醇与多异氰酸酯配合制备了双组分水性聚氨酯,采用红外光谱法研究了室温交联反应过程。研究结果表明:多元醇分子结构中引入苄胺基加快了双组分水性聚氨酯的交联反应速度。将双组分水性聚氨酯制备成水性木器涂料,漆膜具有优异的耐冲击性、附着力、柔韧性、光泽、耐液体介质、硬度、丰满度等性能。     

Synthesis of waterborne polyurethane ink binder with high T-peel strength and its application in biaxially oriented polypropylene film printing

In order to improve adhesion properties of waterborne polyurethane (WPU) inks on biaxially oriented polypropylene (BOPP) films, herein, a liquid polyester polyol BY3003 with long-branched aliphatic chains was used to prepare WPU latexes suitable for BOPP films printing. The application of BY3003 made the surface tension of the prepared latexes not more than 43 mN/m, while that of traditional WPU latex exceeded 55 mN/m. Accordingly, the T-peel strength of the inks made from these latexes was all above 0.8 N/15 mm. In addition, post chain extension degree, dimethylol butyric acid content, and NCO/OH molar ratio also had significantly effect on latex and film properties of WPU, especially on the T-peel strength of the corresponding inks. By optimizing these factors, a WPU latex with surface tension as low as 39.6 mN/m and adhesion fastness over 95% on BOPP film were obtained, and the T-peel strength of its corresponding ink was up to 2.05 N/15 mm, which is the highest value recorded in the literature as far as we know.     

Responses of the amphipod crustaceanGammarus palustris to waterborne secretions of conspecifics and congenerics

A choice-test apparatus designed to mimic field conditions was employed to test for the presence of waterborne attractants in the amphipod crustaceanGammarus palustris. It was found that both males and females were attracted to secretions from all conspecifics, but not to the secretions of a sympatric congener. When given the choice of secretions from different types of conspecifics, males behaved differently than females. Males were attracted more often to receptive females' and females were attracted more often to males' secretions. In the field, then, it is likely that all conspecifics travel toward each other, then sort themselves into competent heterosexual couples. The results suggest that this apparatus can be employed in future studies to determine the chemical nature of these pheromones.     

微波多模腔体对水性聚氨酯涂膜加热仿真分析

水性聚氨酯为水与高分子聚酯材料的混合材料,工业上采用热风和红外干燥方式对水性聚氨酯材料进行干燥存在干燥效率低同时时间长等问题。为解决在传统干燥过程中存在的问题,本文通过使用有限元方法对水性聚氨酯涂膜在多模微波腔体内进行建模,通过测试并拟合水性高分子聚氨酯乳液介电常数随温度的变化曲线;仿真了微波干燥方式下涂膜的温度分布,获得了涂膜整体平均温度随微波功率的变化仿真结果,确定了在相同的时间内有利于水性聚氨酯涂膜干燥的微波功率,仿真了在该微波功率下涂膜整体温度随时间的动态变化过程。