纳米二氧化钛水溶胶对隔热涂料反射可持续性影响的应用探讨

分别制备了不同明度、色相、质感的平涂、水包水、水包砂型反射隔热复合涂层,并使用硅改性丙烯酸树脂和纳米二氧化钛水溶胶对这些复合涂层进行耐污防护,在此基础上考察自然老化时间对这些涂层的反射效果的影响作用。结果表明,对于平涂体系,涂装纳米二氧化钛水溶胶的涂层,与未涂装耐沾污涂层及涂装硅丙罩面涂层相比,其初始光泽和色相不受影响,且耐沾污能力得到了改善,反射能力的可持续性得以提高,中、高明度样品尤为显著,适用于既有反射隔热建筑外涂层的保护涂装或产品改善;质感涂层的耐沾污和反射能力可持续性也是涂覆纳米二氧化钛水溶胶的样品最佳,但是由于其表面平整度过差,导致自洁能力不足以与沾污作用抗衡,故反射性能的维持仍以考虑调整涂层质感和整体明度为主。     

3种黄色颜料对太阳热反射隔热涂层性能的影响

分别以冷颜料(钛铬黄和镍钛黄)和传统颜料(铁黄)制备了太阳热反射隔热涂层,探究了颜料晶体结构和光学性能对涂层性能的影响。采用X射线衍射仪、紫外/可见/近红外分光光度计、红外辐射率测量仪和精密色差仪表征了颜料和涂层的晶体结构、反射比、半球发射率和明度,采用红外灯模拟太阳热源测试了涂层的隔热性能。结果表明:与传统铁黄相比,黄色冷颜料由于晶体缺陷较少而具有更优异的反射性能。镍钛黄颜料所制涂层的隔热性能最佳。铁黄颜料晶体缺陷最多,导致其近红外反射比最低,所制涂层的隔热性能最差。3种涂层的半球发射率均在0.90以上,差别很小,具有较好的辐射散热性能。     

硅粉对钛镍黄有机硅涂层热反射性能的影响

为探索制备低明度热反射颜料的方法,选取不同粒径的硅粉与钛镍黄(Ti Ni Y)混合,再将混合颜料按一定的比例与有机硅树脂混合,制得建筑节能涂料。考察了硅粉粒径及其与钛镍黄的配比对涂层颜色及热反射性能的影响,利用X射线衍射仪、扫描电镜、色差仪和紫外/可见光/近红外分光光度计表征了原料的相组成及形貌,以及涂层的Lab色空间值和太阳光反射率。随着硅粉粒径减小,纯硅粉涂层的明度和太阳光反射率均逐渐升高,而混合颜料涂层的明度和太阳光反射率反而降低;随着硅粉含量增加,涂层的明度持续降低,但太阳光反射率下降到一定程度后不再降低。由某市售白色隔热底层(厚1.00 mm)与Ti Ni Y–Si混合颜料涂层(厚0.05 mm)组成的双层结构涂层的近红外反射率由Ti Ni Y–Si混合颜料单层涂层(厚1.00 mm)的42.41%升高到47.93%。可见硅粉能在降低钛镍黄涂层明度的同时,使反射率保持在一个较高的水平,而采用双层热反射涂层结构既可获得低明度,又能维持一定的热反射能力。     

棕色反射隔热外墙涂层的制备及性能

根据三原色理论,将复合钛红、钴蓝和钛铬黄混合后与苯丙乳液制备了棕色反射隔热外墙涂料,并与单独用铁棕和铁锌铬棕为颜料制备的涂料对比。采用紫外/可见/近红外分光光度计、红外辐射率测量仪和精密色差仪对涂层性能进行表征,用自制装置测试涂层的隔热性能。3种棕色涂层的外观相近,均为低明度涂层,它们的反射比、半球发射率、人工气候老化后反射比变化率等主要性能均符合JG/T 235–2014《建筑反射隔热涂料》的规定。附着力、铅笔硬度、冲击强度和柔韧性差别不大,耐水浸泡72 h无异常。其中混合颜料所制涂层的太阳光反射比和隔热性能最佳,其平衡温度相对空白板降低了12.3℃,但所用原料最贵,铁棕所制涂层的综合性能最差,但成本最低。     

隔热、防腐蚀、装饰涂层体系在车载式安全检查设备上的应用研究

通过太阳光照射试验和碘钨灯模拟太阳光照射试验,获得了“环氧底漆＋环氧中间漆＋太阳热反射辐射双组分丙烯酸涂料”和“环氧底漆＋环氧中间漆＋阻隔型水性隔热涂料”所形成的复合隔热涂层试验数据;设备外表面的隔热涂层通过了耐盐雾、耐酸碱、耐湿热、光泽等性能检测,可以实现产品对涂层体系隔热、防腐蚀、装饰的技术要求。探索出实施复合隔热涂层的工艺过程和操作方法,为车载式安检设备的生产积累了经验。     

不同颜色色浆对氟树脂/铝低红外发射率涂层的影响

研究了大红、深黄、水紫、黑色4种颜色色浆对氟树脂/铝低红外发射率涂层光泽、附着力、硬度、粗糙度、耐冲击性、色差、红外发射率、耐腐蚀性等性能的影响。研究结果显示:深黄色色浆涂层的发射率最低,约为0.1;不同色浆对氟树脂涂层色差明度影响不同,相对于其他色浆,水紫能够使涂层偏暗;大红、深黄、水紫色浆的涂层硬度均为6H;加深黄色浆的涂层附着力最好,其次是大红色浆和水紫色浆;深黄色浆对涂层的耐冲击性影响最大,其次是大红色浆和水紫色浆;相对于大红、深黄、黑色色浆,水紫色浆涂层具有最低的粗糙度,表面比较光滑;水紫色浆和深黄色浆的红外波峰比较持平,有利于减小表面发射率;水紫色浆氟树脂涂层的耐腐蚀性能最好。耐盐水腐蚀测试后4种涂层均没有明显失光,水紫涂层没有发生明显变色,深黄和黑色涂层起泡密度较低。水紫色浆因其粒径均匀细小,在氟树脂涂料中易分散,与氟树脂相容性好,因此具有相对较优的综合性能。     

从熔盐电解废渣中回收钪和氟

为无害化处理熔盐电解法制备铝钪中间合金过程产生的熔盐电解废渣并回收其中的有价元素，针对熔盐电解废渣氟盐高、稀土元素钪含量低的特点，提出了一种氢氧化钠?硫酸两步浸取的全湿法处理熔盐电解废渣，回收氟、钪的新工艺。利用X射线衍射仪(XRD)、X射线荧光光谱仪(XRF)、离子色谱仪(IC)、电感耦合等离子体原子发射光谱仪(ICP-OES)、扫描电镜(SEM)对碱浸?酸浸过程中氟、钪元素的走向分布进行了系统考察。结果表明，碱浸过程中熔盐电解废渣中的氟转化成溶解度较低的氟化钠，通过水洗使氟几乎全部进入溶液，而钪留在碱浸水洗渣中，实现了氟、钪分离。利用碱浸水洗渣中的铝以难溶于酸的?-Al2O3形式存在的特性，通过酸浸将碱浸水洗渣中的钪溶解，实现了钪和铝的分离与回收。通过研究碱浸、酸浸过程中浸出剂浓度、液固比、浸出温度和时间等工艺参数对浸出率的影响，得到最佳工艺参数：碱浸过程氢氧化钠浓度100 g/L，液固质量比12:1，温度90℃，浸出时间1.5 h；酸浸过程硫酸浓度1.5 mol/L，液固质量比6:1，温度90℃，浸出时间50 min。碱浸后熔盐电解废渣中可溶性铝和氟的浸出率分别达97.12%和98.71%，氟化钠产品纯度达到98.70%，酸浸过程钪的浸出率达到92.01%。     

彩色复合型反射隔热涂层的制备及性能

将空心微珠和二氧化钛为填料的涂层做底层,反射型颜料的涂层做表层,制备了阻隔-反射彩色复合型反射隔热涂层。采用紫外/可见/近红外分光光度计、红外发射率仪、精密色差仪和扫描电子显微镜对涂层性能进行表征,自制隔热性能测试装置考察涂层的隔热性能。结果表明,采用复合型涂层结构可显著提高涂层的太阳光反射比和隔热性能,铬绿、群青和铁铬黑颜料掺量分别为20%、20%和10%时,复合涂层的太阳光反射比较高,可达0.646 1、0.602 1和0.539 8,比相同颜料掺量的表层高40.82%、31.03%和58.67%,隔热性能比相同颜料掺量的表层高2.5、1.9和2.8℃,其主要应用性能符合相关标准。     

聚氨酯有机涂层体系的加速光老化降解机理研究

聚氨酯有机涂层在使用过程中,会受到自然界中各种因素的作用而发生老化。其中,太阳光和水是导致涂层老化的最主要的环境因素之一。本文分别采用氙弧灯和荧光紫外灯循环加速光老化来模拟太阳光及水环境,研究涂层的老化规律和降解机理。对比涂层老化前后光泽、色差等外观性能的变化,并用ATR-FTIR(全反射-傅里叶红外光谱)研究涂层表面树脂面漆体系特征官能团的变化情况,结果表明涂层在不同的光老化条件下的老化历程和老化产物不同。     

提高灰色涂层红外反射率的方法研究

以水性纯丙乳液为成膜物质,红外反射颜料为主要颜料,分别以有机颜料、无机颜料、冷颜料相互组合,利用补色调色原理调配相同色相的灰色,重点研究了涂层在近红外区的反射率。结果表明,利用补色原理,使用红外反射颜料和有机颜料或者红外反射颜料和无机颜料,调配的灰色涂层在红外区反射率明显提高。能够达到JG/T 235-2014《建筑反射隔热涂料》中对于中明度涂层(40L*80)在红外光区的太阳光反射率大于L*/100要求。     

Gloss and degradation of hydroxyl polyacrylic resin/hexamethylene‐1,6‐diisocyanate coatings under ultraviolet and natural‐exposure aging

Reactive coatings of hydroxyl polyacrylic resin (HPAR) with hexamethylene‐1,6‐diisocyanate were carried out under accelerated 313‐nm ultraviolet (UV) aging for 2000 h and under natural exposure in Lhasa, Tibet, for 24 months. With UV irradiation and exposure time, the gloss changes in coatings with HPAR containing 3.0% or less hydroxyl groups decreased exponentially, whereas the gloss decay of coatings with HPAR containing over 4.5% hydroxyl groups decreased linearly. During 254‐nm UV aging, the gloss changes in coatings with HPAR containing 1.4% or less hydroxyl groups decreased as a Gaussian function. The weather resistance of a coating was correlated to the HPAR, UV irradiation, temperature, and humidity. Scanning electron microscopy indicated that there were degradation reactions and that some substance was lost in the matrix polymer during accelerated UV aging; then, uneven surfaces appeared and caused decreased gloss. Accelerated UV aging was faster than natural‐exposure aging, and the aging velocity of 254‐nm UV was 3–5 times faster than that of 313‐nm UV. Through the changes in the gloss, the aging tolerance of a coating could be monitored, and its aging resistance could also be predicted. The dynamic mechanical thermal analysis results showed that the coatings had good properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1271–1278, 2007     

A fluorine–silicone acrylic resin modified with UV-absorbing monomers and a free radical scavenger

A novel UV-absorbing and free-radical-catching fluorine–silicone acrylic resin with 2-(4-benzoyl-3-hydroxyphenoxy) ethyl acrylate (BHEA), 2,2,6,6-tetramethyl-4-piperidyl methacrylate (TMPM), dodecafluoroheptyl methacrylate (DFMA) and 3-methacryloxypropyltrimethoxysilane (MPS) as functional monomers was successfully synthesized by solution copolymerization. Based on various investigations, our characterization results for the resin and its coating indicated that the resin exhibits high UV-absorbing and free-radical-catching performances, and the hydrophobicity of the varnish coating was promoted by the actions of fluorine and silicone. In addition, the weatherability improved because of the enduring triple protection of the UV absorbent (BHEA), free-radical-catching agent (TMPM), fluorine (DFMA) and silicone (MPS). After a 1000-h aging test, the color difference (?E) and rate of loss of gloss (?G) of varnish coatings were 2.96% and 62%, respectively, and the impact strength and flexibility of color paint coatings were 420 N cm and 2 mm, respectively. Moreover, the chemically bonded free-radical-catching agent (TMPM) showed a more enduring performance for producing nitroxides than the simple blend.     

A macroscopically nondestructive method for characterizing surface mechanical properties of polymeric coatings under accelerated weathering

The surface of coatings and plastics is the first target in any degradation process initiated by ultraviolet (UV) radiation or mechanical stress (via scratch and abrasion). Surface damage can lead to changes in optical, morphological, and mechanical properties and can result in pathways for ingress of moisture and corrosive agents. Current test methods for monitoring performance of protective coatings focus on chemical properties and optical properties, such as color and gloss measurements, or invasive tests such as abrasion and cross-cut adhesion. In this study, a macroscopically nondestructive performance protocol using nanoindentation metrology via a well-controlled scratch test was applied to evaluate the scratch resistance and monitor the surface mechanical property changes in a protective coating under accelerated weathering. Polyurethane (PU) coatings with different polyol compositions were chosen for this study. Coating specimens were exposed to high-intensity UV radiation at 55°C and 75% RH conditions. Exposed specimens were removed at specified UV exposure times for surface modulus/hardness and scratch resistance characterization via nanoindentation and scratch test. The effect of polyol type and UV radiation dose on the scratch damage (scratch morphology) was investigated and correlated with the surface hardness and modulus of the materials.     

超疏水防紫外双功能水性织物涂层的制备及性能研究

利用乳液缩聚法制备芯材为氟硅烷（ FAS13）壁材接枝紫外吸收剂的二氧化硅微胶囊,将其与有机硅树脂乳液共混,涂覆于棉织物表面形成超疏水防紫外织物涂层。通过扫描电镜和透射电镜观察微胶囊的形态和粒径,并对涂层的水接触角和防紫外性能进行了测试,同时测试了涂层的耐老化、耐磨损、耐高温以及耐酸碱性。结果表明：织物涂层中微胶囊最佳含量为 45%（其中内含 6%紫外吸收剂）,由此制备的涂层表面水接触角可达到 150°以上,并且具有较好的耐老化、耐高温、耐酸碱腐蚀、耐磨损等性能;同时该织物涂层具有优异的防紫外性,紫外线防护系数（UPF）可以达到 111.2。     

含氟嵌段丙烯酸酯聚合物/环氧树脂自分层涂料的制备与性能

利用引发剂连续再生催化剂原子转移自由基聚合(ICAR-ATRP)合成了一系列结构可控的含有含氟丙烯酸酯和甲基丙烯酸缩水甘油酯(GMA)的两嵌段丙烯酸酯聚合物,即聚(甲基丙烯酸丁酯-co-甲基丙烯酸缩水甘油酯)-b-聚甲基丙烯酸十二氟庚酯[P(BMA-co-GMA)-b-PDFHMA,BGF]。将嵌段聚合物与环氧树脂混合制备自分层涂料。傅里叶变换红外光谱(FT-IR)和扫描电子显微镜-能谱分析仪(SEM-EDS)测试表明,当两嵌段聚合物中P(BMA)-co-GMA与PDFHMA的相对分子质量分别为5 300和2 300、GMA结构单元相对分子质量占总相对分子质量的20%,且BGF用量为10%时,漆膜固化过程中含氟嵌段聚合物可以部分迁移到漆膜表面,共混漆膜氟元素自迁移效果较好,表层氟含量达到20%以上,且增加含氟树脂中GMA含量时漆膜氟元素迁移效果下降;耐紫外老化性测试结果表明,含氟树脂的加入使得漆膜的光泽保持率更好,耐黄变性变化不大;水接触角和耐盐雾性测试结果表明,相对纯环氧树脂,加入10%含氟嵌段聚合物使漆膜的水接触角均提高到了100°以上,自分层漆膜的耐盐雾性都有一定提高,可以有效防止漆膜的起泡。嵌段聚合物的加入量低于4%时,对漆膜的基本力学性能没有影响,但光泽有一定下降。     

Investigation of factors impacting the in-service degradation of aerospace coatings

The impact of in-service environmental stressors on the durability of exterior decorative aerospace coating systems was investigated using accelerated weathering for a high-gloss polyurethane-based monocoat with and without clearcoat. Color, gloss, surface roughness, hardness, and chemical composition changes were studied by varying UV irradiance, temperature, thermal extremes, particulate matter, and acid environment while using constant moisture condensation conditions. The use of a clearcoat was found to enhance the resistance to gloss loss regardless of the stressors applied; however, the clearcoat system also produced a larger increase in hardness under all experimental conditions and a larger color shift for all stressors except for the particulate matter and particulate matter combined with acid. A correlation between color shift and chemical degradation was established by monitoring changes in amide and carbonyl functional groups as a function of UV irradiance, temperature, and thermal extremes. The particulate matter, with or without acid was found not to affect chemical degradation, but produced large color shifts for both coating systems and some loss of gloss at high radiant exposures for the clearcoat system. For the accelerated tests studied here, only the highest UV irradiance and temperature level, with or without additional stressors, produced changes in the clearcoat relative to the monocoat system without clearcoat that correlate with in-service performance observations.     

复合型水性丙烯酸酯外墙隔热涂料的研制

根据隔热涂料的隔热机理,通过添加空心玻璃微珠、热反射隔热粉、硅藻土、氧化铝等隔热功能材料,分别制备了阻隔型、反射型、热反射型、辐射型4种水性丙烯酸酯外墙隔热涂料,测试上述4种隔热涂料的隔热温差,以此实验结果为基础,通过正交实验设计得到集阻隔、反射、辐射3种隔热机理为一体的复合型水性丙烯酸酯外墙隔热涂料最佳配方,测试结果表明其隔热温差可达8.7℃,涂膜综合性能优良,无毒环保,对社会节能和环保具有重大的现实意义。     

Optical and surface properties of whey protein isolate coatings on plastic films as influenced by substrate,protein concentration,and plasticizer type

Composite film structures of common plastic polymers including polypropylene (PP) or poly(vinyl chloride) (PVC) with whey protein isolate (WPI) coatings may be obtained by a casting method. Optical and surface properties of the resulting WPI‐coated plastic films, as affected by protein concentration and plasticizer type, were investigated to examine the biopolymer coating effects on surface modification with polymeric substrates of opposite polarity. The measured properties involved specular gloss, color, contact angle, and critical surface energy. Regardless of the substrates, WPI‐coated films possessed excellent gloss and no color, as well as good adhesion between the coating and the substrate when an appropriate plasticizer was added to the coating formulations. The protein concentration did not significantly affect gloss of WPI‐coated plastic films. Among five plasticizers applied, sucrose conferred the most highly reflective and homogeneous surfaces to the coated films. The WPI coatings were very transparent and the coated films with various protein concentrations and plasticizers showed no noticeable changes in color. Experimental results suggest that WPI coatings formulated with a proper plasticizer can improve the visual characteristics of the polymeric substrate and enhance water wettability of the coated plastic films. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 335–343, 2004