水性聚氨酯的改性及水性聚氨酯涂料

介绍了几种水性聚氨酯的改性技术,并对水性聚氨酯涂料的配制及其应用作了相关概述。     

建筑涂料用水性聚氨酯乳液的合成

通过正交试验和单因素试验确定了水性聚氨酯(WPU)的合成工艺条件:异佛尔酮二异氰酸酯(IPDI)与聚丙二醇(PPG-1000)的反应条件为85°C/2h,加入二羟甲基丙酸(DMPA)和1,4丁二醇(BDO)后的反应条件为80°C/2h,n(─NCO)/n(─OH)=(3.8～4.6)∶1,DMPA质量分数为5%～6%,BDO质量分数为8%～9%。通过红外光谱对合成的产物进行了表征,发现异氰酸酯基特征峰消失,氨基甲酸酯键吸收峰形成,说明合成了水性聚氨酯。所合成的水性聚氨酯乳液固含量为34%,具有较好的贮存稳定性。所得涂膜吸水率低(为15%),其耐水、耐碱和耐洗刷性能良好。     

手套涂饰剂用水性聚氨酯乳液的研制

以聚醚二元醇(N220、N240)、聚醚三元醇(N330)、甲苯二异氰酸酯(TDI)、二羟甲基丙酸(DMPA)、三羟甲基丙烷(TMP)和蓖麻油(C.O)等为原料,采用丙酮法合成出水性聚氨酯(WPU)乳液。着重探讨了R值、C.O和TMP用量等对WPU乳液及成膜性能的影响。研究结果表明,当R值为5、m(N220):m(N240)=1:1、选择8%C.O作为交联剂时,所合成的WPU乳液外观好、拉伸强度大、断裂伸长率适中、附着力优良、胶膜光滑细腻丰满且符合手套涂饰剂的涂层要求;与国外同类产品相比,由该WPU乳液所配制的手套涂饰剂的透气性能和价格更胜一筹,完全可以替代同类进口产品。     

UV固化超支化水性聚氨酯涂料的制备

以自制单体6[N-氨乙基-2,2'-二羟甲基丙酰胺]、甲苯-2,4-二异氰酸酯(TDI)和2,2'-二羟甲基丙酸(DMPA)为主要原料,采用准一步法制备了新型WHBPU(水性超支化聚氨酯);然后以此为基体,通过接枝活性稀释剂(羟乙基丙烯酸酯)引入了光活性基团,制备出一种可UV(紫外光)固化的WHBPU涂料。研究结果表明:以固化速率为考核指标,采用单因素试验法优选出制备WHBPU涂料的最佳工艺条件是冰盐浴(-5℃)反应时间为2.0 h、油浴温度为60℃、油浴时间为2.0 h、w(活性稀释剂)=20%(相对于WHBPU乳液质量而言)、w(光引发剂)=3%(相对于干固乳液质量而言)和干燥条件为室温(25℃)干燥2 h→50℃干燥2 h;此时,胶膜的固化速率相对较快、凝胶含量相对最大。     

Characterization of waterborne polyurethane/clay nanocomposite adhesives containing different amounts of ionic groups

A series of waterborne polyurethane (WBPU)/clay nanocomposite dispersions containing different amounts of 2,2-dimethylol propionic acid (DMPA) and clay were prepared. It was found that the properties of WBPU/clay nanocomposites were highly dependent on both clay content and DMPA content. The WBPU/clay nanocomposite dispersion with a higher clay content showed a larger mean particle size and a less negative zeta potential. The optimum clay content, which increased with increasing DMPA content, showed maximum tensile strength, Young's modulus and adhesive strength of WBPU/clay nanocomposite. The optimum clay concentrations for WBPU/clay nanocomposite samples containing 3.75, 5.41 and 6.17 wt% DMPA were about 0.5, 1.0 and 2.0 wt%, respectively.     

Self-healing waterborne polyurethane coating by pH-dependent triggered-release mechanism

In this study, effect of high-loaded silica capsules with corrosion inhibitor on thermal degradation and self-healing properties of waterborne polyurethane (WPU) was investigated. Silica capsules were synthesized using an oil in water (O/W) microemulsion and WPU was prepared via the prepolymer method. Assembled capsules demonstrated pH dependent release of their core. Incorporating silica capsule as an inorganic component resulted to improve thermal and barrier properties of WPU coatings. WPU coating with 1% silica capsules demonstrated better barrier quality in corrosive media and adding more than that resulted a rapid deterioration in barrier properties. Furthermore, such coatings possess an excellent adhesive strength with steel substrate. Electrochemical impedance spectroscopy was used in corrosion monitoring and healing procedure. Moreover, capsule morphology and thermal degradation of the WPU coating has been investigated separately by scanning electron microscopy and thermal gravimetric analysis. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47082.     

Characterization of waterborne polyurethane for ecofriendly functional floor plate

Three types of nonmetallic mineral particles (CaCO₃, TiO₂ and loess) were incorporated into waterborne polyurethane acrylate (PUA) to improve the surface properties of ecofriendly floor tiles. Several properties of PUA containing nonmetallic mineral materials were measured by Fourier transform infrared spectroscopy (FT-IR), a dynamic mechanical thermal analyzer (DMTA), swelling tests, and contact angle measurement. Upon decreasing the molecular weight between crosslinks (variation of molecular weight of the polyol), the modulus and glass transition temperature (T_g) of the PUA film increased because of the increase in crosslinking density. Resistance properties such as swelling and contact angle against water were enhanced with the addition of nonmetallic mineral particles because of the increase in the hydrophobic nature of the polymer matrix.     

Stability and properties of waterborne polyurethane/clay nanocomposite dispersions

Factors that can affect the stability of waterborne polyurethane (WBPU)/clay nanocomposite dispersions are reported. It is suggested that the dispersion stability depends on the carboxyl acid salt content, clay content, sonication (mechanical forces), and clay surface structure. It was observed that the dispersion stability increased with increasing carboxyl acid salt content after applying sonication (mechanical forces) in clay with OH groups (Cloisite 30B) up to 23.58 mol% DMPA. Encapsulated (WBPU20-30B4-M and WBPU23-30B5-M) clay in PU particles was formed using the above combination. The dispersion with clay encapsulated in PU particles had the longest storage time of all of the dispersions. The zeta potential, particle size, particle size distribution, and viscosity of the dispersions also depend on carboxyl acid salt content, clay content, sonication (mechanical forces), and clay surface structure.     

Structure and surface properties of a novel bulk-matte waterborne polyurethane coating composite

This paper reports on a novel self-matte or bulk-matte waterborne polyurethane coating composite with inherently extremely low gloss. The coating composite was comprised of a siloxane-containing waterborne polyurethane (SPU) resin and a crosslinked waterborne polyurethane (CPU) resin. The CPU resin was mainly responsible for fabricating the micro-rough surface of the film, which was achieved by a crosslinking reaction between the waterborne polyurethane and bisphenol A-type epoxy E-44 resin. The SPU resin was used to improve the comprehensive properties of the film, which was ascribed to the addition of silane coupling agent KH792. Compared with traditional matte coatings, this coating composite made it possible to avoid high loadings of matting agent and to arrive at highly flexible low-gloss finishes. Gloss levels of as low as a few tenths of a percent, even at high incidence angles, have been achieved with zero loading of extraneous dulling agent. The chemical structures of the SPU and CPU resins were characterized by FTIR-ATR and NMR spectra. The micro-rough topographies and surface rough degrees of the SPU, CPU and their 50%/50% composite films were measured by SEM and MSP, respectively. The particle sizes and particle morphologies of the SPU and CPU resins were imaged by TEM. Finally, the comprehensive properties of the SPU, CPU and their 50%/50% composite resins were evaluated, including the water contact angle, film transparency, tensile strength and storage stability.     

水性聚氨酯包覆黑索今的性能及影响因素研究

以水性聚氨酯(WPU)乳液作为黑索今(RDX)的包覆材料,以撞击感度和热感度作为衡量指标,采用单因素分析法优选出WPU包覆RDX的最佳工艺条件。结果表明:采用单凝聚法包覆RDX,当RDX的粒度为120~300目(铁筛网)、w(WPU)=2.0%(相对于RDX质量而言)和w(阳离子型表面活性剂)=1%(相对于物质总质量而言)时,RDX的包覆效果较好,此时包覆后RDX的撞击感度和热感度降幅较大。     

Preparation of waterborne polyurethane nanocomposite reinforced with halloysite nanotubes for coating applications

To construct waterborne polyurethane with excellent water resistance and mechanical properties, an organic‐inorganic hybrid nanocomposite based on modified halloysite nanotubes (mHNTs) and polyurethane was prepared. The HNTs were modified with an amino‐silane coupling agent (KH550) and then reacted with polypropylene glycol, 2,2‐Dimethylol propionic acid, and Toluene diisocyanate to form mHNTs/PU aqueous dispersions. The structure of the siloxane functionalized mHNTs was confirmed by a Fourier transform infrared study. The PU/mHNTs composites were characterized by using differential scanning calorimetry, scanning electronic microscopy, thermal gravimetric analysis, a tensile test, particle size analysis, and a water swelling experiment. The tensile strength, Young's modulus, and elongation at the break of the composite polymer with 0.5 wt % mHNTs was shown to be significantly improved, by approximately 200%, 200%, and 30%, respectively. An excess amount of mHNTs could weaken the reinforcing effect and stability of the composite emulsion. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43949.     

UV-curable waterborne polyurethane acrylate modified with octavinyl POSS for weatherable coating applications

UV-curable waterborne polyurethane acrylate (WPUA) modified with octavinyl polyhedral oligomeric silsesquioxane (OVPOSS) was prepared via photopolymerization between OVPOSS and WPUA. Structural and morphological features of WPUA/OVPOSS coatings were assessed using Fourier transform infrared spectroscopy, transmission electron microscopy and X-ray diffraction. Thermal properties of the WPUA/OVPOSS hybride coatings have been improved over the pure waterborne polyurethane acrylate analyzed by thermal gravimetric analysis. Performance of the coatings was also evaluated using water absorption, hardness, contact angle, X-ray photoelectron spectroscopy (XPS). The data showed that the WPUA/OVPOSS coatings possessed better water resistance and thermal oxidative stability in comparison with pure WPUA.     

环氧树脂改性水性聚氨酯阻燃涂料的研究

以E-44环氧树脂改性水性聚氨酯为基料,三聚氰胺、季戊四醇为阻燃剂,制备了一种阻燃涂料.测试了该涂料的附着力、耐水性、吸水率、阻燃性及热失重.结果表明,改性后涂料的涂膜附着力达到1级,耐水时间为240 h,吸水率16.5%,阻燃时间可达10 min以上,耐高温及阻燃性能明显提高.     

光固化纳米二氧化硅/环氧丙烯酸酯杂化涂料的制备与表征

通过在纳米SiO2粒子表面锚固热引发剂,然后在活性稀释单体中对纳米SiO2进行原位接枝聚合改性.将改性纳米SiO2和活性稀释单体的混合物直接与其他原料共混,制备了光固化纳米SiO2/环氧丙烯酸酯(EA)杂化涂料.采用傅立叶变换红外光谱(FTIR)、扫描电镜(SEM)、热重分析(TG)和涂膜性能试验等对杂化涂料的结构与性能进行了研究.结果表明,聚合物链段通过化学键接枝到了纳米SiO2粒子表面;改性后的纳米SiO2在杂化膜中分散良好;在引入改性纳米SiO2后,涂膜的耐热性、抗冲击性、硬度、附着力等性能得到显著改善.     

Highly branched polyurethane acrylates and their waterborne UV curing coating

A series of UV curable highly branched waterborne polyurethane acrylates (BWPUAs) were synthesized using an “oligomeric A₂ + B₃” approach. The thiol-endcapped difunctional oligomeric A₂ was synthesized first by the addition reaction of isophorone diisocyanate, α,α-dimethylol propionic acid and 2-hydroxyethyl acrylate, then further underwent thiol-Michael reaction with 1,6-hexamethylene bis(thioglycolic acetate). Trimethylolpropane triacrylate was used as a B₃ monomer. The molecular structures were characterized with FT-IR and ¹H NMR spectroscopy. 1,6-Hexanediol diacrylate (HDDA) was incorporated into the polymeric chain for preparing the HDDA-modified BWPUAs (BWPUA-Hs). For the comparison, the linear waterborne polyurethane acrylate (LWPUA) was synthesized. The UV curing kinetics study results by using the photo-DSC approach showed that the BWPUAs possessed higher photopolymerization rate and final unsaturation conversion in the UV cured films compared with the LWPUA, which increased with the increase of unsaturation concentration in BWPUA. Moreover, the photopolymerization performance, and water and solvent resistance properties were greatly enhanced by the incorporation of HDDA segment into the BWPUA chain. The dynamic mechanical thermal analysis results showed that the elastic modulus in the rubbery plateau, and the glass transition temperature of UV cured film increased with increasing unsaturation concentration in BWPUA, whereas decreased with the introduction of HDDA flexible segment. The thermogravimetric analysis confirmed the high thermal stability of UV cured BWPUA films. All UV cured BWPUA and BWPUA-H films showed better flexibility and middle refractive indices due to the thioether linkage in the polymer network.     

原位聚合法制备聚酯聚氨脂SiO2纳米复合涂料及性能测试

论述用原位聚合法制备了聚酯聚氨酯/SiO2纳米复合涂料,并利用动态力学分析仪(DMA)、傅立叶变换红外光谱(FT-IR)、紫外可见光谱(UV-VIS)、透射电子显微镜(TEM)、原子力显微镜(AFM)、电子拉力机(Instron Tester)测试了涂膜的性能.结果表明,纳米SiO2粒子均匀分布在涂膜中,并与聚酯通过化学键结合.纳米SiO2粒子的加入提高了涂膜的摆杆硬度、玻璃化转变温度及附着力,并极大地改变了界面形貌,但本文研究的纳米SiO2对聚酯聚氨酯紫外线吸收性和耐磨性没有明显影响.     

原位聚合法制备聚酯聚氨脂SiO2纳米复合涂料及性能测试

论述用原位聚合法制备了聚酯聚氨酯/SiO_2纳米复合涂料,并利用动态力学分析仪(DMA)、傅立叶变换红外光谱(FT-IR)、紫外可见光谱(UV-VIS)、透射电子显微镜(TEM)、原子力显微镜(AFM)、电子拉力机(Instron Tester)测试了涂膜的性能。结果表明,纳米SiO_2粒子均匀分布在涂膜中,并与聚酯通过化学键结合。纳米SiO_2粒子的加入提高了涂膜的摆杆硬度、玻璃化转变温度及附着力,并极大地改变了界面形貌,但本文研究的纳米SiO_2对聚酯聚氨酯紫外线吸收性和耐磨性没有明显影响。     

水性聚氨酯/纳米二氧化硅杂化材料的研究进展

介绍了制备水性聚氨酯(WPU)/纳米Si O2(二氧化硅)杂化材料的几种方法(如纳米Si O2表面改性法、溶胶-凝胶法和原位聚合法等),特别综述了采用化学接枝改性法制备纳米Si O2和溶胶-凝胶法制备共价键连接的杂化材料的研究进展。最后对WPU/纳米Si O2杂化材料的发展方向提出了建议。     

水性聚氨酯/丙烯酸六氟丁酯复合乳液的合成与表征

用甲基丙烯酸-β-羟丙酯(HPMA)与含羧基的聚氨酯预聚体反应得到双键封端的聚氨酯大单体,然后将离子化聚氨酯大单体与丙烯酸六氟丁酯(F6BA)采用乳液聚合法合成了水性聚氨酯/F6BA 复合乳液(FPUL),研究了FPUL的微观结构、热性能、粒子形态和表面自由能.结果表明,通过聚合F6BA接枝到聚氨酯上,且复合乳液具有核...     

Maleopimaric acid‐modified two‐component waterborne polyurethane for coating applications

Maleopimaric acid (MPA), an important rosin derivative, was used to partially substitute isophthalic acid for the preparation of an anionic polyol (MPP) dispersion. The MPP dispersion was then applied to prepare a novel maleopimaric acid‐modified two‐component waterborne polyurethane (MPP‐2K‐WPU). The influences of NCO:OH molar ratio on the thermal properties, water absorption, surface free energy, and application properties of MPP‐2K‐WPU films were investigated. With increasing NCO:OH molar ratio, the thermal stability, pencil hardness, and ethanol resistance of MPP‐2K‐WPU films were improved, but the water resistance was enhanced firstly and then weakened. The surface free energy of MPP‐2K‐WPU films mainly depended on the dispersion interaction which was related to the structure of macromolecules. In addition, compared with the control sample of PP‐2K‐WPU(1.5:1) film, the MPP‐2K‐WPU(1.5:1) film exhibited improved thermal stability, water resistance, gloss, pencil hardness, and ethanol resistance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43292.