Water Absorption and Degraded Stress Relaxation Behavior in Water-Borne Anticorrosive Urethane/Epoxy Coatings

The kinetics of water absorption in water-borne anticorrosive urethane/epoxy coatings, which were actually introduced in the industrial field, are studied. It is found that the high water affinity of a water-borne coating supports a higher saturated water content, Mχ, and helps to facilitate absorption D. The three parameters of stretched exponential function called the William-Watt equation, Eo, τ, and β, are determined to fit the degraded stress relaxation behavior in the water absorption process because this function quantitatively describes the relaxing ability and has been successfully used by a number of researchers. An increasing in the water content is shown to correlate strongly with a decrease in Eo and fl early in the absorption process between Mt/M（χ） = 0 and Mt/Mχ≈ 0.5. The adhesive characteristics of the coatings are correlated with water content, and shown to exhibit higher cohesive failure in coating epoxies under saturated conditions. This suggests that water interferes with the intermolecular bonding between polymer chains which degrades the bulk materials ability to diffuse stress concentrations and reduces its overall strength.

Performace of a Kind of Organic Emulsion Coated Phosphogypsum Particles

The phosphogypsum particles coated with organic emulsion were prepared by coating three kinds of organic emulsion of silicone-acrylic,styrene-acrylic and acrylic.The structure and mineralogical characteristics,acid and alkali resistance,water resistance and dissociation degree of coated phosphogypsum were studied by means of SEM-EDAX,optical microscope,gravimetric analysis and chemical detection.The results showed that the initial emulsion can be used directly for coating and granulation of phosphogypsum.The spray re-coating was carried out by using diluted emulsion with the water-to-emulsion mass ratio of 1∶1.The organic emulsion coated phosphogypsum crystal can be clearly observed,and the mixing zone at internal boundary between the organic emulsion and phosphogypsum crystal was distinguishable under the optical microscope.SEM photos showed that the surface of coated phosphogypsum particles was smooth.And the basic elements of C,O,S and Ca can be detected by EDAX.Organic emulsion can be solidified into film-network between the phosphogypsum crystals inside of the coated particles,and it can play a protective role in improving the acid resistance,alkali resistance and water resistance of phosphogypsum,and reduce the degree of dissociation of phosphogypsum in water.

Application and Properties of Organic Emulsion Coated Phosphogypsum in Aluminous Rock Based Mineral Polymer Composite

A polarizing microscope,X-ray diffraction(XRD),fourier transform infrared spectrometer(FTIR),scanning electron microscope and energy dispersive spectrometer(SEM-EDS),X-ray photoelectron spectroscopy(XPS),and micro computed tomography(Micro CT)were used to investigate the relation between the structure and properties of the composite.Meanwhile,the physical properties,mechanical properties and strength mechanism were researched.The experimental results show that the structure and morphology of coated phosphogypsum remain intact in the composite,which shows good compatibility and forms a clear interface layer of transition zone between the coated phosphogypsum and the matrix,conforming to the structure of particle reinforced inorganic composites.The emulsion coated phosphogypsum has a certain strengthening effect on the aluminous rock mineral polymer composite.The compressive strength of the composite can reach 16.5 MPa when the amount of coated phosphogypsum is 40%,and the apparent density is 1.75 g·cm^(-3),which is significantly lower than that of common concrete;the thermal stability of the composite is also improved to a certain extent.Some certain chemical reactions occur in the process of forming the matrix of aluminous rock mineral polymer materials,with a structure of three-dimensional network.The research will provide a new way for the comprehensive utilization of phosphogypsum and low-grade aluminous rock.

Cellulose Nanocrystals-Coated Polylactide(PLA) Microspheres Obtained via a Pickering Emulsion Approach

In order to prepare cellulose nanocrystals( CNCs)-coated polylactide( PLA) microspheres for the use of drug delivery and tissue engineering,a Pickering emulsion route was applied. The stable Pickering emulsions were prepared using CNCs as efficient stabilizers without any additional surfactant. The microspheres were successfully fabricated after volatilization of the solvent. What's more,the size of microspheres could be controlled by fabrication parameters.

Microencapsulation of UV-Curable Self-healing Agent for Smart Anticorrosive Coating

UV-curable polyurethane prepolymer and photoinitiator 1173 were facilely encapsulated in a poly（urea-formaldehyde） shell, which was in situ formed by the polymerization of formalde-hyde and urea in an oil-in-water emulsion. The diameters of the microcapsules ranged from 118 μm to 663 μm depending on agitation speed, and were obtained via optical mi-croscopy and scanning electron microscopy analyses. The encapsulation percent and the yield of microcapsules prepared at the agitation speed of 600 r/min can reach 97.52wt% and 65.23wt%, respectively. When the water-borne polyurethane （WPU） coating embedded with the prepared microcapsules were scratched, the healing agent could be released from rup-tured microcapsules and lled the scribed region. The excellent anticorrosion properties of the WPU coating embedded with the prepared microcapsules were con rmed by the results obtained from both electrochemical impedance spectroscopy and Tafel curves.

Preparation of Styrene-acrylate Latex Used in Ultralow VOC Building Internal Wall Coating

Styrene-acrylate latex with high glass transition temperature （T）, low minimum film forming temperature（MFT） and good stability was prepared via core-shell emulsion polymerization. With semicontinuous process, high conversion rate of monomer and low gel rate were achieved. The weight ratio of core monomer to shell monomer was approximately 1.35. It is found that many factors such as emulsifiers, initiators, reaction temperature, pH value and polymerization technology have influences on the permormance of styrene-acrylate latex. The prepared latex was characterized by TEM and FTIR. The obtained latex with T of 20.57 ℃, MFT or5.0 ℃, and good stability, had good stability of film forming.

Water-soluble UV curable urethane methyl acrylate coating：preparation and properties

Two kinds of water-soluble and ultraviolet (UV) curable oligomers were synthesized and characterized. The oligomers were evaluated as resins for water-based UV curable coating. The rheology of the two oligomers' aqueous so-lutions was investigated in terms of solid fraction, pH dependence, and temperature dependence. The solutions were found to be Newtonian fluid showing rather low viscosity even at high solid fraction of 0.55. The drying process of the coatings and the properties of the cured coatings were studied by comparing them with water-dispersed UV-curable polyurethane methyl acrylate. It was evident that the water-soluble coating dried more slowly; and that the overall properties were inferior to those of the water-dispersed coating.

Structure, properties and application to water-soluble coatings of complex antimicrobial agent Ag-carboxymethyl chitosan-thiabendazole

The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. The silver ions were preferably coordinated with the free-NH2 groups and the -OH groups of secondary alcohol and carboxyl in CMCTS. TBZ preferably bonded to carboxyl group in CMCTS by electrostatic force and hydrogen bonding. Increase in silver ions content in the complex agent improved to some limited extent the antibacterial activity, but enhanced coloring and cost of the complex agent. Increase in TBZ content resulted in increase of antifungal activity, but decrease of water solubility of the complex agent. The antimicrobial MICs of the complex agent to Esherichia coil, Staphylococcus aureus, Candida albicans, Aspergillus niger, Mucor sp. were 20 -80, 15 -60, 20 - 55, 40 - 250, and 400 - 1700 mg/kg, respectively. Addition of 0.1% of this complex agent to acrylic emulsion paint made the paint without substantial change in color, luster, viscosity, odor or pH value, but with an excellent and chronically persisting broad-spectra antimicrobial activity.

Preparation and Recipe Optimization of Water-based Architectural Heat Insulation Coatings

Water-based architectural heat insulation coatings were studied to overcome the drawbacks of conventional inorganic silicate heat insulation coatings. The heat insulation coatings were prepared with the method of mechanical agitation when the mixed organic polymer emulsions were used as binder of the coatings and the mixed heat insulating aggregates were applied as powder, and some assistants were also added. Water temperature difference in the plastic container, which was coated with heat insulation coatings, represented the heat-insulating property of the coatings. The influences of components of mixed polymer emulsion, mass ratio of polymer emulsion to powder, particle size of heat insulating aggregates, added amount of air entraining admixture and the match of thickeners on the properties of the coatings were studied. The experimental results show that the heat insulation coatings with good finishing, heat-insulation property and artificial weathering can be prepared when the binder is composed of 66.92% styrene-acrylic emulsion, 16.59% elastic emulsion and 16.49% silicone-acrylic emulsion, the mass ratio of polymer emulsion to powder is 0.45, the particle size of heat insulating aggregates is in the rang of 200 and 250 mesh size, the added amount of sericite is 15%, and the added amount of air entraining admixture is in the range of 1.0% and 1.5% and the thickeners are the mixtures of ASE-60 and RM-5000.

Removal of organic solvent from cathodic electrophoretic emulsion paint by vacuum steam stripping

The production of environmental friendly emulsion paint is of great significance. Vacuum steam stripping of methyl isobutyl ketone （MIBK） and methyl ethyl ketone （MEK） from cathodic electrophoretic emulsion was studied. The effects of mass ratio of vapor to feed （V/F）, vacuum degree and feed temperature on removal rate of MIBK and MEK, emulsion size and solid volume fraction of the emulsion were investigated, and the removal of MIBK and MEK from cathodic electrophoretic emulsion by vacuum desorption was also studied. The results show that removal rates of both MIBK and MEK increase with the increase of V/F, vacuum degree and feed temperature. Removal rates of MIBK and MEK are 98.3% and 93.6%, respectively, at the operating condition V/F of 0.7, feed temperature of 27℃ and vacuum degree of 90 kPa. The emulsion size of cathodic electrophoretic emulsion increases slightly with feed temperature when temperature is below 42 ℃, and increases rapidly with feed temperature when temperature is above 42℃. Solid volume fraction increases by 10% as vacuum degree increases from 0 to 90 kPa at V/F of 0.7 and feed temperature of 27 ℃. Compared with vacuum desorption, vacuum steam stripping can get a higher removal rate of MIBK and MEK under the same feed flow, vacuum degree and feed temperature.

Influence of Bitumen Emulsion Spray on Pavement Performance

Bitumen emulsion sprays have an important part to play in the achievement of durable,efficient road pavement construction.Clearly,spraying of bond coats or tack coats at the interface of the bound layers should improve the likelihood of full bond and of resistance to the entry of water through the layers,both of which are needed to meet the design objectives and for the pavement to continue to function properly.BS 594987 recommends bond coats,which are typically polymer modified bitumen emulsion,as best practice and their use is prevalent for the whole range of paved areas in the UK.Recent work examines the effect of different rates of spread of bitumen emulsion sprays on interlayer adhesion and permeability,and attempts to ascertain whether there are optimum quantities to obtain the desired effects.

Influence of Bitumen Emulsion Spray on Pavement Performance

Bitumen emulsion sprays have an important part to play in the achievement of durable,efficient road pavement construction.Clearly,spraying of bond coats or tack coats at the interface of the bound layers should improve the likelihood of full bond and of resistance to the entry of water through the layers,both of which are needed to meet the design objectives and for the pavement to continue to function properly.BS 594987 recommends bond coats,which are typically polymer modified bitumen emulsion,as best practice and their use is prevalent for the whole range of paved areas in the UK.Recent work examines the effect of different rates of spread of bitumen emulsion sprays on interlayer adhesion and permeability,and attempts to ascertain whether there are optimum quantities to obtain the desired effects.

Study of Polyaniline/Vermiculie/Tert-fluoro Emulsion Composites Anticorrosion Coatings

1 Results Polyaniline (PANI) is one of the most promising materials for commercial applications.It can be applied to electronic devices and products such as light-emitting diodes,organic FETs,EMI shielding,secondary batteries,etc.Composites of polyaniline with other polymers or inorganic materials can provide new synergistic properties that cannot be attained from individual materials.Vermiculite (VMT) is a chain-layer magnesium-aluminum silicate mineral.We prepared composite anticorrosion coatings of p...

2024年一季度中国涂料、颜料行业经济运行简析

简析了2024年第一季度我国涂料行业生产、经营和涂料、无机颜料行业进出口简况,并对丙烯酸乳液、环氧树脂等重点成膜物质市场进行了综述和预测。对2024年一季度涂料行业双指数进行了分析,并对二季度市场进行了预测。

丙烯酸-没食子酸基新型改性转锈剂乳液及耐高温涂料的合成研究

转锈剂具有反应条件温和、高效等优点,因此被广泛应用于金属表面的防锈处理。为解决大型钢材建筑除锈难的问题,本研究以丙烯酸、没食子酸为原料,采用种子乳液聚合法制备了一种新型的转锈剂乳液,并以此为成膜物质。以环氧树脂、多异氰酸酯为主要原料,采用溶胶-凝胶法制备了一种耐高温涂料。结果表明,改性丙烯酸转锈乳液粒径相对均匀,涂覆锈转化涂料的样品腐蚀电位为-0.613 V,比裸钢及附着锈钢的腐蚀电位要低得多,对锈转化有一定的抑制作用。通过一系列单因素实验得出耐高温涂料的最佳制备条件为:研磨时间为50 min、分散时间为60 min、颜基比为3.0、漆膜厚度为300μm、固化剂用量为15%。研究制得的转锈剂乳液稳定性较好,耐腐蚀性能优异,可实现金属设备的防腐蚀要求。

硅烷改性环氧苯丙乳液的合成及性能研究

利用硅烷偶联剂KH-560和环氧E-51,通过种子乳液聚合的方法,对传统苯丙乳液进行有机硅与环氧树脂改性,制备了新型的硅烷改性环氧苯丙乳液,并探索了工艺条件对乳液性能和涂膜性能的影响。结果表明:乳化剂用量为6.5%、软硬单体比例为1.6∶1、环氧树脂E-51用量为5%、硅烷偶联剂KH-560用量为10%时,合成出的新型硅烷改性环氧苯丙乳液具有较高的固含量与转化率,分别为43.75%、87.5%,具有较低的凝胶率和吸水率,分别为0.98%、71.43%,乳液外观呈乳白带明显蓝相,乳液稳定性良好。初步研究了硅烷偶联剂KH-560和环氧树脂E-51对苯丙乳液的改性机理。

极端顶点法制备碳酸钙超疏水涂层

目前,超疏水涂层存在着制备成本高、工艺复杂和环境污染等问题,阻碍了其工程化应用进程。文章以CaCO_(3)晶须及其纳米粒子为填料,水性苯丙乳液为粘结剂,以及硬脂酸锌为疏水改性剂制备超疏水涂层。首先采用油酸对CaCO_(3)晶须及其纳米粒子进行表面改性,然后基于极端顶点设计将改性后的CaCO_(3)晶须、改性后的纳米CaCO_(3)、苯丙乳液和硬脂酸锌为混合分量进行混料实验,以涂层接触角为响应变量建立回归模型,分析混合分量对接触角的影响。结果表明:采用不同形貌的CaCO_(3)粉体复合苯丙乳液可制备出超疏水涂层,在纳米CaCO_(3)与硬脂酸锌混合分量较高,CaCO_(3)晶须混合分量较低以及苯丙乳液适中的区域,接触角可达153.5°。通过表面形貌分析,涂层的黏附性与其表面的孔洞有关,而较高的纳米CaCO_(3)混合分量可降低涂层表面粗糙度,促进其超疏水性能。

氧化石墨烯/氟硅丙-苯胺复合乳液的制备及其涂层的防腐蚀性能

[目的]为了提高丙烯酸酯乳液涂层的防腐蚀性能,需在乳液聚合时引入功能单体,并在乳液中添加功能填料,以阻止腐蚀介质的侵入。[方法]以甲基丙烯酸十二氟庚酯(DFMA)、乙烯基三甲氧基硅烷(VTMS)及苯胺(Ani)为功能单体,通过无皂乳液聚合法制备了氟硅丙烯酸酯-苯胺共聚乳液(FSiAc-Ani);再以木质素磺酸钠为改性剂,制备了磺酸改性氧化石墨烯(SO_(3)H-GO)。在Q235钢表面制备了磺酸改性氧化石墨烯/氟硅丙-苯胺共聚乳液(SO_(3)H-GO/FSiAc-Ani)复合防腐蚀涂层。探讨了改性GO的种类、用量及不同的复合方法对复合涂层性能(尤其是防腐蚀性能)的影响。[结果]当SO_(3)H-GO用量为1.25%(相对于FSiAc-Ani乳液的质量)时,SO_(3)H-GO/FSiAc-Ani复合涂层的干、湿附着力均为0级,吸水率为1.78%,水接触角为96.56°,低频阻抗模值最大,腐蚀电位最正,腐蚀电流密度最小。[结论]相比于单纯共混的硅烷改性氧化石墨烯/聚苯胺/氟硅丙乳液(Si-GO/PANI/FSiAc)和磺酸改性氧化石墨烯/聚苯胺/氟硅乳液(SO_(3)H-GO/PANI/FSiAc)复合涂层,SO_(3)H-GO/FSiAc-Ani复合涂层对Q235钢具有更优异的防腐蚀性能。

BaSO_(4)/ZrO_(2)隔热涂层的制备及性能

[目的]BaSO_(4)不仅成本低,来源丰富,而且具有较高的太阳光反射比和半球发射率,但作为隔热填料应用于涂料中时,隔热性能不如金红石型TiO_(2)和SiO_(2),因此需要对BaSO_(4)进行改性以提升其隔热性能。[方法]以BaSO_(4)及ZrO_(2)粉体为原料,通过煅烧法获得BaSO_(4)/ZrO_(2)粉体,并以BaSO_(4)/ZrO_(2)粉体为隔热填料,纯丙乳液为成膜物质,制备BaSO_(4)/ZrO_(2)隔热涂层。利用X射线衍射仪(XRD)、傅里叶变换红外光谱仪(FTIR)、扫描电镜(SEM)和能谱仪(EDS)对粉体的化学结构及形貌进行表征,并探讨ZrO_(2)添加量对涂层性能的影响。[结果]随着ZrO_(2)添加量的增加,涂层的太阳光反射比、近红外反射比和半球发射率均先升高后降低,隔热温差先增大后减小。当ZrO_(2)添加量为5%(质量分数)时,涂层的太阳光反射比为0.809,近红外反射比为0.785,半球发射率为0.92。此时,BaSO_(4)/ZrO_(2)涂层的隔热温差达到11.29℃,与BaSO_(4)涂层相比高3.12℃,与以未煅烧BaSO_(4)/ZrO_(2)制备的涂层相比高4.52℃。[结论]本研究结果可为基于改性BaSO_(4)的隔热涂料技术和产品的开发提供参考。

水性苯丙吸波涂层的制备与性能研究

吸波涂料是一种能够吸收和衰减入射电磁波的功能涂料,而水性吸波涂料更具有环保健康的特点。选择炭黑和羰基铁粉作为复合吸波剂,加入水性苯丙乳液中制备成本较低的复合吸波涂层。首先测试了炭黑和羰基铁粉的电磁参数,并计算得出成分为12%炭黑和70%羰基铁粉,厚度为2mm时吸波性能最佳,反射损耗优于-5dB的有效吸收频宽达到9.9GHz,反射损耗峰值达到-28.6dB。然后制备了含12%炭黑和70%羰基铁粉,厚度为2mm的苯丙吸波涂层,测试分析了苯丙吸波涂层的吸波性能以及涂料相关性能。