高力学性能医用聚氨酯手套的制备研究

利用水性聚氨酯乳液,采用浸渍成型工艺制备聚氨酯手套。考察了交联剂、TiO_2、温度等条件对聚氨酯薄膜力学性能的影响。结果表明:在不降低手套力学性能的前提下,可添加一定量的二氧化钛作为颜料,添加交联剂可以改善聚氨酯手套的力学性能,并达到行业要求。     

水性聚氨酯原料的选择

详细介绍了制备水性聚氨酯所需的原料，包括聚多元醇(聚酯／聚醚)、二异氰酸酯、亲水扩链剂、交联剂、扩链剂、溶剂、成盐剂及催化剂。并对原料种类、用量多少的选择对制得的水性聚氨酯性能的影响进行了详细的论述。     

水性聚氨酯研究进展

综述了水性聚氨酯的性能、制法,改性研究及应用。     

A complete new design for waterborne 2-pack PUR coatings with robust application properties

In this paper, a new approach to the paint composition design of WB 2-pack PUR coatings for car refinish application is presented. New hydroxy-functional binder emulsions are described that offer a better basis for the mixing process and the pot-life/reactivity balance with polyisocyanate hardeners. In addition, it will be shown that with these binder systems the overall balance of appearance, pot-life and curing speed can be enhanced to a very attractive level by the use of a well tuned catalyst package, allowing sufficient time for application, flow and de-aeration while offering the required fast curing characteristics as well. Thirdly, it will be shown how the aspects relating to undesired foam formation can be managed. Finally, the performance of low VOC paint compositions for car refinish application based on this new generation of WB 2-pack PUR system will be discussed.     

Wettability of waterborne coatings on chemically and thermally modified pine wood

Modification of wood can change its hydrophilic character. Consequently, modified wettability of wood can change its behavior with coating or gluing processes. The authors investigated the wettability of oil-heat-treated and DMDHEU-modified Scots pine wood with some commercial waterborne coatings. The increased hydrophobic character of modified wood was revealed from high advancing contact angles of water. In contrast, exterior waterborne coatings exhibited much better wetting on modified substrates than on unmodified substrates. Good wetting of modified wood by waterborne coatings is an interesting result, opening up possibilities for application of environmentally friendly waterborne surface systems on modified wood.     

Effect of nano-ZnO addition on the silicone-modified alkyd-based waterborne coatings on its mechanical and heat-resistance properties

A silicone-modified alkyd-based waterborne coating was developed using hexamethylmethoxymelamine (HMMM) as crosslinking agent and para-toluene sulphonic acid (p-TSA) as catalyst. The crosslinking ratio for resin and HMMM was fixed to 70:30, based on FTIR and DSC studies. Nano-ZnO particles were added to this system in different concentrations. The coatings with nano-ZnO particles were characterized using FTIR and DSC. The nano-composite coatings were applied on mild steel panels and were cured at 130 °C for 30 min. The coatings were evaluated for their mechanical and heat-resistance properties. They were exposed to 350 °C for 10 min followed by water quenching. The process was repeated for 10 cycles. Heat-resistance property of the coatings was examined by TGA. Also, surface morphological changes were assessed using SEM and optical microscopy. It was found that the heat-resistance and mechanical properties of the coatings improved significantly as a function of nano-ZnO addition.     

Synthesis of UV crosslinkable waterborne siloxane–polyurethane dispersion PDMS-PEDA-PU and the properties of the films

A UV crosslinkable waterborne siloxane–polyurethane dispersion, PDMS-PEDA-PU, was synthesized by incorporating acrylate groups into the side chain of the polyurethane using pentaerythritol diacrylate (PEDA). Polysiloxane groups were introduced into the soft segment of the polyurethane using polydimethylsiloxane (PDMS). They formed a crosslinking structure after UV radiation. The structure of PDMS-PEDA-PU was confirmed by the use of Fourier transform infrared spectroscopy (FTIR). X-ray diffraction (XRD) analysis indicated that the formed PDMS-PEDA-PU was amorphous. The curing rule of PDMS-PEDA-PU was investigated on the basis of the change in C=C conversion during the UV curing process. The influence of the PDMS/PEDA ratio was studied with respect to the water resistance, the thermal property, and the mechanical property of the films.     

UV-cured coatings based on waterborne resins and SiO2 nanoparticles

The UV curing technique in combination with the use of waterborne resins is very attractive since it gives the opportunity to get solid coatings by means of ecofriendly processes. We found that it is possible to use such UV curable water-based formulations as matrices for the preparation of nanocomposites in which the filler is generated in situ by means of the sol–gel chemistry. We prepared silica-based nanocomposites and characterized them comparing their performances with those of the silica-free coatings. Moreover, the article discusses the influence of the addition of a coupling agent between the organic and inorganic phase on the final properties of the nanocomposite.     

微晶高岭石/环氧树脂复合改性水性聚氨酯的研究

用十六烷基三甲基溴化铵,十二烷基三甲基溴化铵,对微晶高岭石进行有机化处理,得到有机微晶高岭石;以有机微晶高岭石、环氧E-51复合改性,制备了有机微晶高岭石/环氧树脂复合改性的水性聚氨酯（OMMT/E-51WPU）。研究了有机微晶高岭石、2,2-二羟甲基丙酸和环氧E-51的质量分数对乳液及涂膜物化性能的影响。结果表明：当w（OMMT）=1.5%,w（DMPA）=4.0%,w（E-51）=4.0%,乳液及膜的物化性能较好,乳液呈透明蓝光,吸水率为5.9%,接触角98°,拉伸强度32MPa,断裂伸长率571%。     

Preparation and characterization of waterborne ceramic ink with submicron-sized praseodymium-doped zirconium silicate pigment by water-based diblock polymer dispersants

Two diblock polymer dispersants (i.e., PMAA-b-AMPS and PSSS-b-GMA) were synthesized and used as water-based dispersants for dispersion and stabilization of waterborne ceramic ink with submicron-sized praseodymium-doped zirconium silicate (Pr-ZrSiO₄) pigment. The color property, dispersion, and stability of the pigment particles in aqueous suspension were determined by colorimetry, laser particle size analysis, and sedimentation test. The adsorption mechanism of carbon chains of dispersants on the particle surface was analyzed by Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy and electrokinetic potential measurement. Also, the viscosity, surface tension and stability of waterborne ceramic ink with the pigment particles were measured by rheometry, surface tension analysis and standing settlement. The results show that the submicron-sized pigment particles in waterborne ceramic ink show optimum dispersibility and stability at 5 wt% addition of diblock polymer dispersants PMAA-b-AMPS and PSSS-b-GMA mixed in a mass ratio of 9:1. This could be since the mixed dispersants provide the more interparticle electrostatic repulsion and steric hindrance energies due to the proper adsorption on the particle surfaces. It is indicated that adding 20 wt% of diethylene glycol monobutyl ether into the waterborne ceramic ink can effectively enhance the viscosity and reduce the surface tension, thus satisfying the applied requirements in inkjet printing. In addition, the jettability of waterborne ceramic ink on a simulated ceramic green body was also evaluated based on semi-empirical analysis.