粉煤灰在功能建筑涂料中的研究进展

粉煤灰在我国产量巨大但消纳有限,粉煤灰的主要成分为硅铝化合物,性质稳定,对其进行改性可以增强活性,然后与功能助剂结合制备涂料,利用粉煤灰制备建筑功能涂料不仅可以实现粉煤灰的资源化利用,还可以降低绿色建筑材料的成本。本文结合粉煤灰的结构和性质,简述了其在功能建筑涂料方面的应用,主要从防火涂料、防水涂料、隔热保温涂料、相变涂料、防腐涂料以及其他功能涂料等几种涂料的作用机理及粉煤灰在其中的作用进行了研究,表明了粉煤灰在建筑功能涂料方面具有良好的应用前景。最后,对粉煤灰在功能建筑涂料方面存在的问题及发展方向进行了总结和展望。     

甲醛捕捉剂改性粉煤灰内墙涂料的制备和性能研究

对粉煤灰进行湿法改性后在其表面负载甲醛捕捉剂,可以得到改性的粉煤灰粉末,以其为填料制备内墙涂料,依据GB/T 15516—1995检测其粉体及该内墙涂料对室内空气中甲醛的消除效果。结果表明:甲醛捕捉剂能很好地负载在改性后的粉煤灰颗粒表面;负载粉煤灰及其涂料对室内甲醛具有很好的消除效果,尤其当粉煤灰涂料的颜料体积浓度(PVC)与临界颜料体积浓度(CPVC)相近时,涂层具有最优的甲醛捕捉效果;同时常规性能满足GB/T 9756—2009的要求,可以被应用到内墙涂料中。     

粉煤灰在防腐涂料中的研究进展

生活中的腐蚀现象带来了许多安全隐患与经济损失，涂料防腐因其操作简单且效果显著而得到了广泛的应用。近年来，粉煤灰由于自身的结构以及优异的理化性质，作为一种防腐涂料中的填料物质引起了广泛的关注。粉煤灰的加入替代或部分替代了防腐涂料中的材料物质，大大降低了原材料的经济成本，提高了固废资源的利用率。本文结合粉煤灰的基本性质，从涂层的物理屏蔽效应、力学性能、电化学保护三个方面论述了其耐腐蚀性的原理，并阐明了粉煤灰在其中起到的作用。从制备涂层过程中使用的基料入手，将现阶段的粉煤灰防腐涂层分为三种主要类型：粉煤灰环氧树脂防腐涂层、粉煤灰硅酸盐防腐涂层、其他类型的粉煤灰防腐涂料。并对每种类型的涂料现有的研究进展和使用的粉煤灰的性质进行了总结和概括。粉煤灰用于防腐涂料的研究现阶段仍然停留在实验室规模，因为成本和工艺原因，难以实现大规模的工业化应用且存在性能单一、耐久性差的问题。因此开发低成本且具有自修复、自清洁和抗污染特性的粉煤灰防腐涂层是亟须解决的难题。     

粉煤灰填充涂料的研究进展

为进一步挖掘粉煤灰的资源化利用潜力,扩宽其应用范围,减轻其对环境的污染压力,本文介绍了粉煤灰的形成、组成、利用现状与存在问题,讨论了粉煤灰填充涂料的种类、工艺、组成与性能,包括粉煤灰填充隔热涂料、粉煤灰填充铸造涂料、粉煤灰填充防水涂料、粉煤灰填充防火涂料、粉煤灰填充其他功能涂料,并指出将粉煤灰作为填料用于涂料,开发各种功能性涂料,是粉煤灰资源化利用的研究重点之一。     

丙烯酸涂料的改性与功能化研究进展

介绍了丙烯酸涂料的改性与功能化研究进展,并展望了其未来的发展方向.丙烯酸涂料改性方面的研究主要有用环氧树脂、有机硅树脂、有机氟树脂和聚氨酯树脂等对其接枝或混拼;用无机纳米填料或功能化助剂对其杂化改性,赋予其特殊的功能.     

改性粉煤灰内墙调湿涂料的制备及其性能

采用改性粉煤灰制备内墙调湿性涂料是对固废粉煤灰在功能涂料中应用的新尝试。通过测试不同颜料体积浓度的粉煤灰内墙涂料的吸放湿性能,发现其在涂层中颜料体积浓度(PVC)与临界颜料体积浓度(CPVC)接近时调湿性最优,同时涂层的接触角出现了一个拐点。粉煤灰涂料经过多次水洗后,外观变化较小,当粉煤灰涂料的PVC≤CPVC时,涂层(4#与5#)各方面性能可以达到GB/T 9756—2009《合成树脂乳液内墙涂料》中的要求,可以被应用于内墙涂料中。     

废弃红砖制备保温隔热水性涂料及优化

为提高建筑废弃物资源化利用效率,本研究以废弃红砖作为典型建筑废物,选择阻隔型和反射型作为研究方向,探究涂层厚度和颜料体积浓度对砖粉水性涂料保温隔热性能的影响,并加入空心玻璃微珠、粉煤灰漂珠、膨胀珍珠岩、木质纤维、海泡石和硅酸铝作为功能填料,提高砖粉水性涂料的保温隔热性能。实验结果表明:(1)当涂料层大于7 mm时砖粉水性涂料涂层发挥阻隔隔热效果,且厚度增加对隔热效果影响显著。在实验范围内,反射隔热效果受涂层厚度影响不明显。(2)砖粉填料中添加功能填料能提高阻隔隔热效果,降低隔热所需涂层厚度,其中空心玻璃微珠和粉煤灰漂珠效果最好,膨胀珍珠岩和海泡石效果次之,而木质纤维和硅酸铝的效果较差。     

反射隔热多彩涂料的制备及性能探讨

以现有纯色反射隔热涂层的制备工艺为基础,对水性多彩涂料进行改进,包括特殊颜、填料的使用及层结构的设计,讨论了基材处理、底涂、色点、颜料等诸多因素对涂层性能的影响,并讨论了改进罩面体系对多彩涂层的重要性;经改进后的多彩仿石涂层体系被赋予了反射隔热性能,其太阳光反射比、近红外反射比、沾污后太阳光反射比下降率均可符合标准JGJ/T 359—2015建筑反射隔热涂料应用技术规程的相关要求,进一步为水性多彩涂料的功能化和拓展使用提供了空间。     

粉煤灰空心微珠强化厚型钢结构防火涂料的制备及性能

将小粒径粉煤灰空心微珠(FAC)作为隔热填料掺入厚型钢结构防火涂料中,研究了FAC掺量对涂料理化性能及耐火性能的影响.结果显示:FAC掺量为8％时得到的防火涂料整体性能最优,灼烧3 h的背温低于市售防火涂层.利用数据模型对防火涂料耐火试验过程参数进行计算,求得固定和平均这2种形式的等效热阻,再以其模拟钢构件受火过程的温升情况,结果与实测基本一致.探讨了涂层表现出耐火性的原因.     

功能填料对反射隔热涂料隔热性能影响的研究

根据隔热机理的不同,配制了添加不同功能填料的反射隔热涂料;利用自制装置测试了室内和室外环境下涂覆不同反射隔热涂料试件的内部温度;研究了二氧化硅气凝胶、相变胶囊、六钛酸钾、钛白粉、陶瓷微珠、红外辐射粉等功能填料对实际应用环境中涂层隔热性能的影响。结果表明:尽管碘钨灯光与日光在不同波段能量分布差异较大,但2种光源照射下试件的温度变化结果一致,说明利用碘钨灯模拟太阳光测试涂料的太阳光照射下的隔热性能是可行的。添加反射型和辐射型填料的涂料最佳干膜厚度约300μm,而添加阻隔型和相变型填料的涂料的隔热降温效果随干膜厚度增加而增加。在太阳辐射作用下,反射型填料隔热降温效果最好。夜间室外环境中,填料的热辐射性能对涂层的降温效果影响不大。     

Studies on the effect of titanate coupling agent (2.0%) on the mechanical properties of flyash‐filled polybutadiene rubber

Flyash, a waste product of thermal power stations, generated in huge quantities, has been posing problems of disposal. Attempts have been made for its utilization as a filler in elastomers and plastics; however, it has been established that untreated flyash does not at all contribute in enhancing mechanical properties of composites. The purpose of this work was to make meaningful utilization of flyash as a filler, by treating it with a titanate coupling agent and to use it as a filler in PBR. The properties under consideration were tensile strength, modulus at 100 and 400%, Young's modulus, hardness, etc. Composites were made with varying proportion of untreated and treated flyash. A two‐roll mill was used for dispersing the filler in the rubber, and a compression‐molding technique was used to cure the compound in sheet form. Tensile properties were measured on a computerized UTM using an ASTM procedure. Comparison of properties of composites filled with treated and untreated flyash established that treatment of flyash imparts better reinforcing properties. Tensile strength was improved by 50%, while modulus at 400% was improved by 400%. Similarly, Young's modulus also was improved by 209%. The Titanate‐coupling agent used here has promoted adhesion between flyash and the PBR. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1293–1298, 2004     

灰色弹性隔热阻燃外墙涂料的研制

以纯丙弹性乳液与改性硅溶胶复配为基料,以特种功能型热反射粉、改性聚磷酸铵为功能填料,以钛白粉和自配黑为颜料,在矿物填料和助剂的配合下,制备的灰色弹性外墙涂料,经检测其涂膜具有优异的热反射隔热性、耐火阻燃性、耐候耐水性、耐沾污性等特点。     

Ablation behavior of inorganic particle-filled polybenzoxazine composite coating irradiated by high-intensity continuous laser

Further utilization of aircraft structural materials is threatened by the fact that high-intensity continuous lasers are widely used in the field of military defense. To protect the aircraft structure from laser damage, ammonium polyphosphate filled polybenzoxazine composite coatings were prepared on the substrate. The anti-laser ablation characteristics of the coatings were investigated. Results showed that the addition of the inorganic filler improved the anti-laser ablation performance of polybenzoxazine. The back-surface temperature of substrates covered with the composite coatings was more 50% lower than that in the case of a pure polybenzoxazine coating after laser ablation. Further, the residue of the composite coating could be vertically divided into three distinct regions, with the dense surface char layer and the porous pyrolysis layer acting as shielding layers for the laser beam and preventing any heat-related transformations from occurring. The addition of the inorganic particles improved the surface reflectivity of the coatings resulting in much more laser energy dissipation. The decreased pyrolysis rate ensured that the pneumatic cooling effect of pyrolysis gas was more lasting and stable, owing to which the composite coatings could act as effective thermal protection layer for longer. These results confirmed that the inorganic filler modified polybenzoxazine coating exhibits excellent anti-laser properties and are suitable for protecting structural materials from laser-related damage.     

A novel composite protective coating with UV and corrosion resistance: Load floating and self-cleaning performance

The research in functional materials has been the focus in studying industrial applications, particularly in the field of superhydrophobic functional bionic material. Although many studies of superhydrophobic surfaces have been published at this stage, the performance remain unsatisfactory, especially in a variety of harsh environments in practical applications, such as extremely cold weather, acidic or alkaline environment, prolonged exposure to light, high temperature, or oily wastewater, etc. The mechanical strength and corrosion resistance of coatings in such environments are all mighty challenges. In this study, we propose a fluoro silane-modified zinc oxide (FAS-ZnO) as a nano-filler. A superhydrophobic and oleophobic composite coating was successfully prepared through a single step by spraying suspensions containing attapulgite (ATP), FAS-ZnO, and carboxylated polyphenylene sulfide (PPS–COOH) onto desired substrates. In addition, stearic acid was added as a binder and used to enhance the bonding strength between the filler and the substrate. The composite coatings were characterized by FE-SEM, XRD and FT-IR on substrates, and the corrosion resistance of the coatings was evaluated by electrochemical impedance spectroscopy (EIS) and salt spray chamber experiments. The composite coatings showed excellent corrosion resistance due to the synergistic effect of FAS-ZnO and ATP. It was found that the composite coating had good hydrophobic and oleophobic contact angles of 161 ± 1.5° and 159 ± 1°, respectively, which were mainly attributed to the construction of nano-scale structures. It is worth noting that the composite coating performed excellently in chemical stability, self-cleaning performance, UV resistance, anti-fouling function, mechanical strength, and load-bearing floating ability. The coating maintained its highly hydrophobic surface after being stretched through a universal testing machine. Based on the multiple key properties in the composite coating, it can be expected to be applied to large equipment and instrument surfaces in extreme outdoor environments.     

Utilization of Flyash as Filler Material in Hybrid Polyester Composites for Improved Thermo-Mechanical and Erosion Wear Behavior

The present work was carried out for the utilization of major quantities of flyash as filler material in the short fiber reinforced polyester resin composites in various engineering and structural applications. The incorporation of flyash modifies the hardness, tensile, flexural, impact and damping behavior of the composites. It is observed that hardness, flexural modulus and impact strength of flyash filled composites increases with increase in the flyash filler contents. Whereas, with the addition of flyash contents it is observed that there is decrease in tensile strength and flexural strength. But beyond the 10 wt.-% flyash filler addition in the composite the flexural strength increases. At the end, the erosion wear behavior of all the composites has been studied by Taguchi experimental design. It is found that unfilled glass polyester composite suffers greater erosion loss as compare to particulate filled glass polyester composites. The eroded surface morphology is examined by SEM and the related erosion wear mechanism is discussed in detail.     

浅色厚浆型导静电环氧涂料的研制

研制成一种浅色厚浆型导静电环氧涂料。介绍了该涂料的配方和制备工艺。讨论了导电填料和颜填料用量,以及助剂对涂层电阻率的影响。实验结果表明：该涂料与同类产品性能相当,但它的应用范围更广,可在苛刻环境条件下使用,经济优势明显。     

Preparation of polyvinylpyrrolidone/graphene oxide/epoxy resin composite coatings and the study on their anticorrosion performance

Waterborne epoxy resin (EP) is often used as anticorrosive coating in the industrial field. However, small holes and gaps can be formed during the curing process. The corrosive medium easily penetrates the anticorrosive coating and corrodes the metal matrix. Herein, polyvinylpyrrolidone (PVP) and graphene oxide (GO) were doped into EP to improve the shielding and resistance to corrosive media. The composite coatings were prepared successfully by solution blending method. In the PVP/GO composite materials, original spatial structure of GO was changed and the composite was mainly combined by covalent bonding. The surface morphology of hybrid filler was flat and uniform, and the structural defects of GO was reduced. Compared with single-layer anticorrosive coating, the corrosion potential of PVP/GO/EP coating moved forward and the corrosion current density decreased. The ideal corrosion resistance of PVP/GO/EP composite coatings was mainly because agglomeration of GO sheet was obviously avoided after it was modified by PVP. Furthermore, the hybrid filler can be uniformly dispersed in the aqueous EP. It blocked the gaps and holes inside the coatings, which could contribute to form anticorrosive coatings.     

Properties of powder coatings in load carrying construction

The present study describes the mechanical behavior of powder coatings used under very high compressive loads in clamping force joints. Carboxyl functional polyester powder coatings cured with hydroxyl functional β-hydroxyalkylamides with variations in coating thickness and amount and type of filler, have been studied. The coatings were subjected to conventional tests for coatings and polymers and also to specially designed tests developed to study the behavior of powder coatings in clamping force joints. The specially designed tests were used to study the coatings under compressive loads, and the relation between the results from these test methods and from conventional tests is discussed. The results show the importance of coating thickness in order to achieve the desired mechanical properties of a coating when used under high compressive loads. These loads put high demands on the stability of the coating, and the defects must be kept to a minimum. Increased thickness will give rise to more defects in the coating, especially voids and blisters due to the evaporation of water formed during the curing of the polyester powder coating. The surface roughness of the coating is also affected by the coating thickness, but the main influence originates from the type and amount of filler used. A rough surface will give rise to stress concentrations and increased plastic deformations in the coating, impairing the properties of the clamping force joint.     

Tribological properties of polyimide coatings filled with PTFE and surface‐modified nano‐Si3N4

Polyimide (PI) coatings filled with PTFE and nano‐Si₃N₄ were prepared by a spraying technique and successive curing. Nano‐Si₃N₄ particles were modified by grafting 3‐aminopropyltriethoxysilane to improve their dispersion in the as‐prepared coatings. Friction and wear performances and wear mechanisms of the coatings were evaluated. The results show that the incorporations of PTFE and modified nano‐Si₃N₄ particles greatly improve the friction reduction and wear resistance of PI coating. The friction and wear performance of the composite coating is significantly affected by the filler mass fraction and sliding conditions. PI coating incorporated with 20 wt % PTFE and 5 wt % modified nano‐Si₃N₄ displays the best tribological properties. Its wear rate is more than one order of magnitude lower and its friction coefficient is over two times smaller than that of the unfilled PI coating. Differences in the friction and wear behaviors of the hybrid coatings as a function of filler or sliding condition are attributed to the filler dispersion, the characteristic of transfer film formed on the counterpart ball and the wear mechanism of the coating under different sliding conditions. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40410.     

Oligosilazane cured by moisture as fluorine-free hydrophobic coating for waterproof polymer-matrix composite materials

Preceramic oligosilazane was applied as a waterproof hydrophobic surface coating for electromagnetic wave-transmitting material (silica cloth-reinforced bismaleimide laminated composite). Oligosilazane spread readily on the surface of the material, due to its good wetting ability, enabling formation of silazane coatings using various processing methods such as spraying, dipping, wiping, etc. When using oligosilazane containing micrometer-sized silica particles as filler, a hydrophobic surface was realized after moisture curing under ambient condition. The hydrophobic surface with oligosilazane coating inhibited water absorption shows promise for application as a waterproof surface coating of electromagnetic wave-transmitting materials.