自烧结泥浆和涂料的研究

对高纯用Al2O3质泥桨采用SHS法和反应烧结法,使这种高耐火度并耐浸蚀的泥浆能在1300℃烧结并具有良好的结合性能。对同类型涂料进行的试验也取得了相同的结果     

自烧结泥浆和涂料的研究

对高纯Ａｌ２Ｏ３质泥浆采用ＳＨＳ法和反应烧结法,使这种高耐火度并耐浸蚀的泥浆能在１３００℃烧结并具有良好的结合性能。对同类型涂料进行的试验也取得了相同的结果。     

自分层涂料的机理和研究现状

介绍了自分层涂料的基本概念和形成自分层涂料的预测理论，讨论了形成自分层涂料的推动力和形成机理，简述了自分层涂料的发展现状和应用领域。     

自清洁涂料

0306204自清洁烤箱用催化涂料:DEIO 150 825[德国专利·德]/德国:Bsh Bosch Und Siemens HausgeraeteGmbh(Joerdens,Frank等)一20034.17一6页一10 150825(2001.10.15):IPC C09D7/06 自清洁食品烤箱用催化涂料含无机多孔粒子,在孔中不含固体或液体第二相。自清洁涂料     

自烧结炭材料的制备和性能研究

考察了球磨时间对生焦粉的粒度、粒度分布、挥发分含量的影响．以及生焦粉的上述物性参数对自烧结炭材料性能的影响，并初步分析了其影响机制。     

自清洁涂料

一种荷叶效应自清洁氟碳涂料;一种抗污自洁氟碳艺术毛面幕墙板及其制备方法;一种自清洁氟碳树脂涂料及其制备方法;一种自清洁氟碳树脂涂料及其制备方法。     

自清洁涂料

级单或多元酸,(D)为含)1个狱基(在其。位的碳上带有夕1个H)的a,p一烯属不饱和单体〔双丙酮(甲基)丙烯酸胺]0 .01一5份,并将80%~98%的上述单体加入含占单体总量的2%~20%的预乳化聚合产物的反应性介质中,聚合得最终的聚合物分散体。例如,将含丙烯酸2.50份、丙烯酸丁醋61.40份、苯     

自清洁涂料

0402216自清洁表面用修补树脂以及制备程序:DE10 205 784[德国专利]/德国:Degussa AG(Nun,Edwin等)一2003.8.21一10页一10 205 784(2002.2.13);IPC C09D5/00 用于修补自清洁表面的自清洁涂料组合物含有含结构粒子(如在表面上纳米范围不规则细结构的无机材料)的可固化聚合物。一     

自修复涂料的研制

本文研制的自修复涂料系统含有许多特点,硅氧烷单体自修复剂HOPDMA-PDES按相分离分散在介质中,而同时催化剂在微胶束中,HOPDMA与PDES不会发生反应,只有当催化剂从微胶束中破壳而出与自修复剂完全混合并固化后,自修复剂才完成任务。     

Preparation of TaB2-SiC oxidation protective coating for carbon materials by liquid phase sintering

To control the microstructure and amounts of TaB₂ phase in the TaB₂-SiC coating, a novel liquid phase sintering method was developed on the basis of in-situ reaction method to prepare the TaB₂-SiC coating, which includes synthesis of TaB₂ powders and further preparation of TaB₂-SiC coating. With Ta₂O₅, B₂O₃ and C employed as raw materials, hexagonal TaB₂ powders were prepared by carbothermal reduction method at 1500?°C, whose mean particle size is 491?nm. The TaB₂, SiC, C powders, and the low melting point phases Si and silica sol were used to prepare the TaB₂-SiC coating by liquid phase sintering at 2373?K. The thickness of the coating is about 350?µm. Compared with the SiC coating, the weight loss of the samples modified by TaB₂ decreased from 17.7% to 11.8%, and the average weight loss rate of the fastest weightloss zone reduced from ?6?×?10^?3 mg?cm^?2 s^?1 to ?5?×?10^?3 mg?cm^?2 s^?1. During oxidation, the Ta-oxides would gradually dissolve in the silicate glass to form Ta-Si-O glass ceramics with dendritic structure, which significantly improved the toughness and stability of the glass layer. The Ta-Si-O glass ceramics possesses the ability of sealing and arresting the microcracks, which can enhance the oxidation protective ability of the coating.     

Flexural behavior of bamboo-fiber-reinforced mortar laminates

This paper reports the flexural behavior of bamboo-fiber-reinforced mortar laminates. The laminate considered in this study is a sandwich plate combined with reformed bamboo plate and extruded fiber-reinforced mortar sheet. Due to its high strength to weight ratio, the reformed bamboo can remarkably strengthen the mortar and reduce the total weight of the laminate. Test results show that, for the laminates with reformed bamboo plate on the bottom as tensile layer and fiber-reinforced mortar sheet on the top as compressive layer, the flexural strength values can be improved to greater than 90 MPa.     

Long-term forecast of Ca leaching from mortar and associated degeneration

The purpose of this study is the long-term forecast of Ca leaching from mortar and degeneration with Ca leaching. First, a technique for long-term forecasting of Ca leaching from mortar was constructed. Here, Ca is made to dissolve out by combining the electrochemical acceleration test with the diffusion test; it was converted on the basis of Ca leaching rate in real time and was carried out to a long-term forecast of Ca leaching. Next, the long-term forecast technique of mortar degeneration with Ca leaching was constructed. Here, Ca is made to dissolve out by the electrochemical acceleration test, and the mortar was evaluated experimentally. The result of the accelerated degeneration test was checked with the real time conversion result obtained by the long-term forecast of Ca leaching. Finally, predicted results of the degradation with Ca leaching were compared with the survey result of existing structures used for 30 years.     

Experimental study of gas and liquid permeability of a mortar

Eight samples cored from the same mortar were used to investigate their respective gas, ethanol and water permeability. Two gas and liquid permeability cells, using special devices for measuring the injected flow under steady conditions, were designed and presented in this paper. The obtained results showed that water permeability was systematically lower (in an order of magnitude from 1 to 2) than gas permeability whereas ethanol permeability was intermediate between these two values. Nevertheless, ethanol and gas permeabilities were found of the same order and, when gas permeability is corrected from the Klinkenberg (or slippage) effect, the results given by these two fluids are virtually identical and can be considered to be the intrinsic permeability value. Thus, the differences observed between water and gas permeability values have to be explained by other phenomena such as rehydration, dissolution and migration of fine elements or water adsorption in the thinnest pores.     

Study on the performance of a new type of water-repellent admixture for cement mortar

A special water repellent for mortar is made from the combination of polyacrylamide as a principal raw material and FDN-2 as an additive. Every item of comparison test and research for the technical features of the compound water-repelling admixture (CWRA) has been carried out in building antiseepage mortar. The result shows that the main properties of the mortar have satisfied China's national standard. The permeability of mortar added with the agent has been greatly improved. The mortar has high effective penetration resistance and good workability. This paper discusses the waterproofing mechanism of the agent.     

Reinforcing steel passivation in mortar and pore solution

Under field conditions, steel is embedded in concrete for a long period of time before chlorides penetrate. In studying the corrosion behaviour of steel in concrete, mortar or in simulated pore solution, it is essential to allow enough time for the steel to create a passive layer which is the subject of this study. This time is given to steel in chloride free concrete, naturally; while it should be provided to steel in synthetic pore solution, before adding chloride to the solution. For determining this time, samples were made with steel with different surface conditions: as-received with mill scales and sand-blasted. One set of steel bars (as-received and sand-blasted) were embedded in mortar and one set were immersed in synthetic pore solution. Corrosion of each steel bar was monitored every hour by LPR technique for total time of 300 h. Also, half-cell potential of steel bars was measured during that time. Results show that steel needs to be kept at least three days in synthetic pore solution and seven days in mortar to be passivated.     

X-ray absorption study of drying cement paste and mortar

X-ray absorption was used to observe water evaporation with hydration time in paste and mortar specimens, with the aim of studying the influence of water/cement (w/c) ratio, presence of aggregates, curing conditions on drying during early hydration. For the samples subjected to surface drying immediately after mixing, there exists a moisture gradient within the internal part of the specimen. However, obvious top-down drying only occurs within a small zone near the surface for early age cement pastes and mortars. The evaporation rate of water is very high in the first day after casting and is drastically reduced afterwards due to the formation of a microstructure that greatly improves specimens resistance to moisture loss. Mortars reveal a slightly lower evaporation rate since the aggregate increases the length of the transport route because of a larger tortuosity. However, the effect of sealed curing is much more important than the tortuosity effect of the aggregates.     

Packing effect and pozzolanic reaction of fly ash in mortar

This research is to study the effect of particle size of fly ash on packing effect and pozzolanic reaction of mortar when 20% of fly ash is used to replace Portland cement type I. Both effects can be determined by using fly ash and insoluble material which have almost the same particle size to replace Portland cement type I. Normally, the compressive strength of fly ash mortar is contributed from hydration reaction, packing effect, and pozzolanic reaction. For mortar mixed with insoluble material, the compressive strength is due to hydration reaction and packing effect. Thus, compressive strength due to pozzolanic reaction can be determined from the difference in compressive strength between fly ash mortar and insoluble material mortar. The results show that the strength activity index of fly ash mortar depends on the median particle size of fly ash and curing ages of mortar samples. At early ages, the strength activity index of fly ash mortar due to packing effect is higher than that due to pozzolanic reaction. At the ages of 3 to 90 days, the difference in strength activity index due to packing effect of fly ashes with median particle size of 2.7 and 160 μm is almost constant about 22% of the strength of standard mortar (STD). The differences in strength activity index due to pozzolanic reaction of fly ashes with median particle size of 2.7 and 160 μm are 3%, 20%, and 27%, respectively, at the ages of 3, 28, and 90 days.     

The effect of mullite coating and microwave sintering on high temperature oxidation resistance of MWCNTs

Multi-walled carbon nanotubes (MWCNTs) are considered as a promising material for nanocomposites fabrication due to their magnificent characteristics. However, challenges including low oxidation resistance (oxidized above 530 °C in the air) and weak interfacial adhesion, etc, restrict their use at high temperatures. Coating the surface of MWCNTs seems a promising way to control its oxidation and to increase interfacial adhesion. To the best of our knowledge, the coating of MWCNTs by mullite has not been reported yet, so that in this paper, mullite-coated MWCNTs (20 wt %) was fabricated by sol-gel method to improved oxidation resistance of MWCNTs. The uniform mullite shell was sintered through two methods of microwave and conventional heating. The effect of sintering temperature and type of heating on mullitization, crystallization and oxidation resistance of MWCNTs were investigated. Microstructural investigations revealed that the surface of MWCNTs is uniformly covered by mullite and TGA results showed the increase in oxidation temperature (≈300 °C). In addition, the obtained results confirm that the microwave method could be a better technique for obtaining a dense, smooth and crystallized coating layer than the conventional one for improving oxidation resistance of MWCNTs.