UV固化的环氧丙烯酸树脂耐磨加硬涂层的制备及性能

本文通过环氧树脂和丙烯酸为原料反应合成了环氧丙烯酸树脂(EA),然后用硅烷偶联剂3-甲基丙烯酰氧丙基三甲氧基硅烷(MPS)对其进行改性,得到可紫外光固化的有机硅耐磨透明涂层,并对涂层的各种性能进行了测试,如硬度测试、附着力测试和耐磨性能测试等.结果表明,相比未涂覆的有机玻璃基材,涂覆后的有机玻璃基材的表面硬度和透光率均有所增加,且随硅烷偶联剂含量的增加而有所提高.对耐磨涂层的热稳定性也进行了研究,结果发现,改性后的环氧丙烯酸树脂的热稳定性要明显好于未改性的.     

新型含氟涂层在镀锡板上的抗腐蚀性能及机理

硅烷改性含氟乳液用于金属表面处理时环保,且工艺简单、成本低廉,但目前研究较少。以含氟乳液和γ-(2,3-环氧丙氧基)丙基三甲氧基硅烷(KH560)为主成膜物质,同时添加无机钛、锆金属盐,制备新型含氟钝化液,并对镀锡板进行钝化处理。通过纳米粒度仪和红外光谱仪对含氟乳液进行表征,采用电化学、附着力、抗硫性、中性盐雾试验和原子力显微镜等测试方法对镀锡板表面涂层的性能进行测试,并探讨了其钝化机理。结果表明:含氟乳液的平均粒径为59.68 nm,稳定性良好,氟单体参加了反应;含氟镀锡钝化板的耐蚀性相对于空白板的明显提高,其耐蚀效果与成品有铬镀锡板相当,附着力达到标准1级,抗硫性优于成品有铬镀锡板,涂层表面趋于致密平整。     

UV固化的环氧丙烯酸树脂耐磨加硬涂层的制备及性能（英文）

本文通过环氧树脂和丙烯酸为原料反应合成了环氧丙烯酸树脂(EA),然后用硅烷偶联剂3-甲基丙烯酰氧丙基三甲氧基硅烷(MPS)对其进行改性,得到可紫外光固化的有机硅耐磨透明涂层,并对涂层的各种性能进行了测试,如硬度测试、附着力测试和耐磨性能测试等。结果表明,相比未涂覆的有机玻璃基材,涂覆后的有机玻璃基材的表面硬度和透光率均有所增加,且随硅烷偶联剂含量的增加而有所提高。对耐磨涂层的热稳定性也进行了研究,结果发现,改性后的环氧丙烯酸树脂的热稳定性要明显好于未改性的。     

环氧改性不饱和聚酯

通过粘度、超声速率及折射率研究氯仿中的环氧／不饱和聚酯混合物的可混性；应用于防水材料的不饱和聚酯树脂的组成；反复使用的聚乙烯基对苯二酯中得到的乙烯基酯存在下的不饱和聚酯压缩特性及固化性能；环氧聚合物改性光敏性不饱和聚酯的制备；耐热双马来酰亚胺改性不饱和聚酯树脂；用于生产储存稳定的不饱和聚酯树脂的含引发剂的微胶囊.     

高固体分环氧海洋防腐蚀涂料的研究进展

海洋环境中,钢结构的腐蚀不可避免,有机涂层是一种延缓金属腐蚀的最有效、最经济的材料之一。其中高固体分环氧涂料由于绿色环保、涂层致密性好、可厚涂等特点在海洋重防腐中得到广泛的应用。对目前高固体分环氧厚膜、超厚膜涂料的研究进展,存在的问题及解决方法进行了详细的介绍。其中,环氧树脂、胺类固化剂作为环氧涂料中的主要的成膜物质,对涂层的性能起着关键的作用。总结了几种在高固体分环氧涂料中切实可行的环氧树脂增韧改性方法,同时指出开发耐冲击性能优异,耐高温,低温固化、水下固化的环氧固化剂也是环氧固化剂的发展趋势。通过曼尼希碱改性合成的环氧固化剂,恰好能满足各种性能的要求,阐述了该类环氧固化剂的合成研究进展状况。     

聚酯树脂基粉末涂料的制备及性能

粉末涂料在工业生产中日益得到广泛应用,但目前国内研制的性能优异的粉末涂料及相应的涂装技术相对较少。通过研究聚酯树脂、固化剂、颜料、填料、助剂等原辅材料种类及配比对涂膜性能的影响规律,确定出以P9335聚酯树脂为基材,以异氰脲酸三缩水甘油酯(TGIC)为固化剂,以金红石型R996钛白粉为颜料,辅加流平剂及其他助剂,按照一定配比混合制备成聚酯树脂基粉末涂料。涂膜试验结果表明:涂层外观光滑平整,与基材结合力强,抗冲击、抗划伤及耐候性能均较为优异。     

氧化石墨烯/聚酯树脂涂层的制备及耐腐蚀性能

石墨烯具有阻隔性好、机械强度高、比表面积大等优异的性能,被广泛应用于防腐涂料领域.本研究在聚酯树脂粉末中加入分散性较好的氧化石墨烯(GO),利用静电喷涂技术在经硅烷偶联剂预处理的6063铝合金基体上制备了不同氧化石墨烯含量的聚酯体系涂层.通过EDS能谱分析硅烷膜的成分,并通过电化学试验评价硅烷膜的腐蚀行为;采用纳米压痕仪表征涂层与基体的结合力;通过全浸泡试验和中性盐雾试验研究氧化石墨烯添加量对聚酯体系涂层耐腐蚀性能的影响.结果表明,硅烷膜的自腐蚀电压为-0.831 V,自腐蚀电流密度为5.361×10-8 A/cm2,钛锆膜的自腐蚀电压为-0.967 V,自腐蚀电流密度为8.350×10-8 A/cm2,即与钛锆膜相比,硅烷膜的自腐蚀电位高、自腐蚀电流密度小,耐腐蚀性能更优;经硅烷偶联剂预处理涂层的临界载荷值LC1为2035.71 mN,LC2为3066.66 mN,均大于经钛锆膜预处理的涂层的临界载荷值(1667.40 mN),即经硅烷偶联剂预处理的涂层与基体的结合力更强;与未添加氧化石墨烯的聚酯涂层相比,氧化石墨烯添加量为0.5％(质量分数)的聚酯涂层的失重量及失重率最小,1000 h盐雾腐蚀后涂层表面的孔隙和腐蚀坑也均减少,其耐腐蚀性能明显增强.即在聚酯树脂涂料中添加0.5％(质量分数)氧化石墨烯时,涂层的耐腐蚀性能显著提高.     

分散法合成树枝状超支化聚酯及其表征

以三羟甲基丙烷、邻苯二甲酸酐和环氧丙醇为原料,探索了发散法合成末端含大量羧基和羟基的第一代、第二代树枝状超支化聚酯,并且通过测定分析研究了合成条件及性能.这种树枝状超支化聚酯具有可控的精确结构,大量分子末端基团易于改性,粘度低,热稳定性好,是一种性能优良的高分子材料,在光固化涂层和粘合剂等领域具有广阔的应用前景.     

改性纳米氧化锆与水性聚氨酯复合涂层的防腐蚀性能

为了改进纳米氧化锆(ZrO_2)在涂料中的分散性,以丙酮为介质,用3-氨基丙基三甲氧基硅烷(APS)对纳米ZrO_2进行了改性,并在镀锡板表面制备了改性纳米ZrO_2/水性聚氨酯(WPU)复合涂层。通过扫描电镜、原子力显微镜、红外光谱、电化学测试、盐雾腐蚀、附着力测试等技术,研究了WPU与不同含量改性纳米ZrO_2复合涂层的防腐蚀性能。结果表明:改性纳米ZrO_2的含量为0.2%(质量分数)时,在WPU中的团聚现象消失,分散性良好,该复合涂层具有优良的耐蚀性和较大的附着力。     

硅烷偶联剂在金属表面预处理中的应用研究进展

近年来发展的硅烷偶联化预处理技术因其对环境友好、可操作性强,有望成为金属表面铬钝化处理的替代工艺。硅烷膜作为金属表面预处理层,不但改善了基材表面的状态,增强了涂料与基材间的黏附性能,也可作为单独的防护涂层,对腐蚀介质的渗透起着物理屏障作用。主要从3个方面介绍了硅烷偶联剂在金属表面预处理中的研究进展:(1)金属表面硅烷偶联化机理;(2)金属基材表面状态、硅烷水解体系、硅烷成膜方式及膜固化方式等工艺对膜性能的影响;(3)硅烷预处理技术研究的新进展,包括传统浸渍成膜、电沉积辅助法制备硅烷膜及无机稀土金属盐、纳米颗粒、缓释剂掺杂制备的硅烷杂化膜的研究现状。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...