正硅酸乙酯的水解缩聚反应及其应用

简要阐述了正硅酸乙酯水解缩合的反应机理,同时结合笔者的相关实验结果,介绍了在正硅酸乙酯预聚物基础上的各类改型树脂,以及这些树脂在特殊涂料上的应用。     

中孔炭材料的制备及吸附性能的研究

以正硅酸乙酯为模板硅源，酚醛树脂为炭前驱体，运用模板法制备了中孔炭材料。并用红外光谱（FT—IR）、扫描电镜（SEM）、低温N2自动吸附、甲醛和VB12饱和吸附等对样品形貌、孔结构和吸附性能进行了研究。结果表明：制备的炭材料孔径集中分布在2-7nm左右，且中孔孔隙率达到74．6％，比表面积达到1012m^2／g；材料对VB12大分子有较好的吸附性能。表明通过控制正硅酸乙酯的水解条件能制备孔径集中的中孔炭材料。     

正硅酸乙酯水解过程的研究进展

本文综述了近几年来正硅酸乙酯水解、缩合反应历程的研究进展，并讨论了影响反应速率和反应历程的因素。     

MQ硅树脂的合成工艺研究

以正硅酸乙酯（TEOS）、六甲基二硅氧烷（MM）为主要原料,在浓盐酸的催化作用下,合成MQ硅树脂。讨论合成过程中影响MQ硅树脂性能的主要因素,如反应物配比、反应时间、反应温度等。最终确定MQ硅树脂的最佳合成工艺条件：反应时间为3h,反应温度为60-70℃,正硅酸乙酯、六甲基二硅氧烷、水、乙醇和盐酸（35％重量浓度）的质量比为40／12／8．8／5／2．4。     

正硅酸乙酯与异丙醇反应产物的气质联用色谱分析

对正硅酸乙酯与异丙醇反应产物进行了气质联用色谱分析，结果检测出17个组分，为含不同异丙氧基取代数的正硅酸酯[（i—PrO）n（EtO）4-nSi]，也包括取代产物的二聚物和三聚物。由此证实了缓释粘贴剂在制备过程中不是简单的物理混合，而是发生了乙氧基和异丙基交换反应；同时，计算出该混合物中正硅酸乙酯与异丙醇的量之比约为0．5：1。     

毛细管气相色谱法测定正硅酸乙酯

以HP-5毛细管柱为色谱柱,醋酸戊酯为内标物,采用氢火焰离子化检测器(FID),定量测定正硅酸乙酯含量。峰面积与浓度呈良好的线性关系,r=0.9999,精密度良好,回收率99.1%～101.2%。     

反应条件对合成单分散二氧化硅微球的影响

采用正硅酸乙酯、氨水、异丙醇和水为原料,合成了微米和亚微米级二氧化硅微球,着重研究了实验温度、氨水浓度、正硅酸乙酯的用量、加水量以及反应时间对该反应的影响。结合对所合成产物的扫描电镜表征,确定了制备不同粒径、均匀的单分散二氧化硅微球的实验条件。     

正硅酸乙酯酸度测定方法的研究

正硅酸乙酯(TEOS)是一种无色液体,主要用作防热涂料、耐化学作用的涂料、有机合成中间体。其酸度对其质量有直接的影响。本文通过试验探索了正硅酸乙酯酸度的测定方法,借鉴有机试剂含量测定不应加入水的经验,结合酸碱测定,使用中性无水乙醇做为溶剂。本实验中的氢氧化钠滴定液分为水溶液和乙醇-氢氧化钠溶液,并对2种溶液的滴定结果进行比较与讨论,最终建立正硅酸乙酯酸度的测定方法,为正硅酸乙酯的质量的鉴定提供一种可靠依据。     

石刻保护有机硅涂料的研究

以正硅酸乙酯和甲基三乙氧基硅烷为主要原料，在酸催化下，在醇溶液中经水解缩聚制备出石刻保护有机硅涂料。讨论了单体配比、用水量、溶剂、催化剂、反应温度和时间对涂料性能的影响，得出最佳的反应条件，并对产品的性能进行了测试。     

无机富锌底漆固化剂影响因素的研究

溶剂型无机富锌底漆以正硅酸乙酯的水解液为固化剂。研究了正硅酸乙酯水解的各种因素,如水解度、催化剂、水解介质、水解温度、催化剂滴加速度等对水解液性能的影响。     

The chemistry of ethyl silicate binders in refractory technology

The chemistry of the processes involved when an alkyl silicate such as ethyl silicate acts as a binder in refractory technology is described. The gel forming process involving catalysed hydrolysis and condensation of ethyl silicate and tetra-alkyl silicates has been studied using amine catalysts. Thermal studies of gels obtained from technical ethyl silicate and of gels obtained from technical ethyl silicate incorporated in refractory materials, together with infrared spectroscopy studies of gels obtained from technical ethyl silicate, suggest the nature of the degradation products, and the weight-loss patterns observed support the proposed mechanisms.     

Chloride-free biodegradable organic acid hydrolyzed zinc silicate coating

Partially hydrolyzed ethyl silicate has widely been used as a binder to formulate inorganic zinc silicate paint for anticorrosive coating applications. Hydrochloric acid is used most popularly to catalyze the hydrolysis of ethyl silicate. Although different acids have been tried as catalysts for ethyl silicate hydrolysis, no attempt has been made to make stable paints out of those hydrolyzed silicate binders. In this study, environment benign biodegradable organic acids such as oxalic acid, citric acid, lactic acid and acetic acid were used for the hydrolysis of ethyl silicate and compared with the hydrolysis using conventional hydrochloric acid. The hydrolyzed silicate sols were pigmented further with silica powder and evaluated for their stability. Of the various organic acids catalyst used, only oxalic acid catalyzed sol acted as a stable binder system. The pigmented binder was then mixed with metallic zinc to formulate anticorrosive inorganic zinc silicate paint. The resultant coatings were characterized for various physical, surface, mechanical and chemical resistance properties such as drying, hardness, adhesion (cross hatch) and solvent resistance. Corrosion resistance properties were analyzed by means of salt spray, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS). The results revealed that the physical, mechanical, chemical and anticorrosive properties of the coating hydrolyzed with hydrochloric acid and oxalic acid are comparable. Thus, a chloride free biodegradable organic acid hydrolyzed inorganic zinc silicate primer is reported and due to its long term stability same also can be scaled up commercially.     

Some features of the production of thermal-shock-resistant cast corundum materials in ethyl silicate binders

Conclusions The use of ethyl silicate binders of an optimal composition makes it possible to produce cast corundum articles with a mullite-corundum binder with excellent characteristics.The best combination of properties is found in the articles when binders of optimal composition, close to stoichiometric, are used in the hydrolysis reaction of the ethyl silicate.The destruction and sintering processes in the corundum casts in an ethyl silicate binder during heat treatment are produced by the destruction kinetics of the hydrolysis products of the ethyl silicate and by the presence in them of active SiO₂. The sintering of articles of such a composition begins at 1100°C. The excellent thermal-shock resistance of the ceramic made from masses with ethyl silicate binders and the slower destruction of these ceramics result from the rational phase composition and structure of the material.Translated from Ogneupory, No. 2, pp. 35–39, February, 1982.     

醇溶性无机富锌涂料的研制

醇溶性无机富锌涂料是以硅酸乙酯水解液为A组分,聚乙烯醇缩丁醛为B组分基料,配以锌粉以及其他填料、助刺、溶剂等制成。简要阐述了醇溶性富锌涂料成膜机理和对硅酸乙酯水解配方的研究,以及锌粉添加量对防腐性能的影响。     

无机硅酸锌预涂底漆的研制

介绍了无机硅酸锌预涂底漆成膜机理、硅酸乙酯水解、改性及主剂的制备。通过对硅酸乙酯改性,增加了无机硅酸锌预涂底漆漆膜的柔韧性;采用耐盐雾实验选择了防锈颜料磷酸锌、B-004磷铁粉及5%的锌粉添加量;通过对比无机硅酸预涂底漆的施工性、耐盐雾性及储存稳定性,确定了聚乙烯缩丁醛树脂液的加量,选用了HX-8800和BYK-420作为产品防沉剂,调整溶剂体系添加1%CB溶剂控制漆膜干燥速度,并最终确定了产品配方。此产品满足流水线自动喷涂工艺,干燥时间短、防锈性能好、可与多种面漆配套使用,并且不影响焊接和切割。     

A new study on binder performance and formulation modification of anti-corrosive primer based on ethyl silicate resin

Zinc-rich ethyl silicate coatings are quite successful in protecting steel against corrosion under severe exposing conditions. In spite of providing excellent cathodic protection to steel structure after film curing, two-component zinc-rich ethyl silicate coatings have some limitations, one of which is inadequate shelf life as a result of in-can binder gelation.     

适合压载舱涂层配套的船用车间底漆的研制

介绍了车间底漆的制备、性能的测试.讨论了硅酸乙酯在不同当量的酸性和碱性条件下的水解情况,碱性条件下反应剧烈,不易控制,且制得的水解液贮存期短;不同型号的硅酸乙酯经水解后,硅羟基的含量不同,导致交联密度也不同,使车间底漆涂层与钢材间的附着力产生较大的差异;分析了不同锌含量对车间底漆性能及与压载舱主涂层配套性的影响.     

硫化剂对有机硅密封剂耐热性能的影响

分别以含氢硅油、正硅酸乙酯、甲基三丁酮肟基硅烷和ND-42为硫化剂,研究了不同温度条件下硫化剂对双组分缩合型室温硫化有机硅密封剂耐热性能的影响。     

A novel method for the hydrolysis of ethyl and isopropyl silicates

The hydrolysis of ethyl and isopropyl silicates without the use of an acid or base catalyst is described. The silicate and an alcohol which is a mutual solvent for water and the silicate are treated with water, preferably under reflux. For ethyl silicate the reaction temperature can be as low as 40°C. A liquid hydrolysate is obtained when the rate of water addition is carefully controlled. This hydrolysate will form a rigid coherent gel capable of binding refractory materials. Liquid hydrolysates prepared in this way have been used to make refractory shapes, also foundry moulds and cores for precision piece moulding work and an ethyl silicate hydrolysate can be used to prepare an anti-corrosion paint based on zinc. It would be expected that other lower alkyl silicates can be treated similarly to form hydrolysates which give a rigid coherent gel capable of binding refractory materials and which can also be used to prepare anti-corrosion paints based on zinc.     

Preparation and properties of some acyloxysilanes

Acyloxy derivatives of silicon were prepared by the interchange reaction between carboxylic acids (including various grades of palmitic acid) and tetraethoxysilane, and by the interchange reaction between palmitic acid and technical ethyl silicate (silica content 40%) or technical isopropyl silicate (silica content 38%). In most of the reactions, sodium methoxide was used as catalyst. Some physical properties of the reaction products were determined, and the materials made from palmitic acid were evaluated as water-repellent coatings on cotton cloth.