高强度系列密封胶投产

高强度系列密封胶投产国内第一条高强度系列密封胶生产线最近在山东建成投产，其中的聚氨酯型、有机硅型两种密封胶填补了国内空白。这条生产线引进了瑞士的密封胶先进生产技术和意大利、德国的现代化先进设备，现已投产了聚氨酯型、有机硅型、ＰＶＣ型、丁基橡胶等五大类...     

硅烷封端聚氨酯密封胶的制备及其应用

密封胶是用来填充空隙的材料,最早使用的密封胶有沥青类、油性嵌缝胶等。而用于须经受震动或热胀冷缩等伸缩性间隙,则必须采用弹性密封胶。弹性密封胶是将粘接和密封两种功能集于一体的产品。其中高性能密封胶有三类：聚硫密封胶、硅酮密封胶和聚氨酯密封胶。聚硫密封胶是应用最早的一类弹性密封胶,它一般以铅类氧化物作固化剂,低温固化速度慢,固化物压缩性大,老化后易变硬且有开裂现象发生,胶料呈臭味,因此近年来消费量逐渐下降。硅酮密封胶是二十世纪六十年代问世的一种有机硅弹性体,它以羟基封端的聚有机硅氧烷与交联剂相配合作为基础胶料,依靠空气中的水分硫化。随交联剂的品种不同,可分为醋酸型、醇型、酮肟型、酰胺型、丙酮型等。     

水基预涂型锁固密封胶概况

国外从20世纪70年代就开展预涂型锁固密封胶的研究及应用工作,因其可部分代替液态型厌氧胶,提高汽车等机械行业生产自动化水平,国内也从上世纪80年代开展预涂型锁固密封胶的研究,并在东风汽车公司成功应用;预涂型锁固密封胶分溶剂型及水基型两大类,水基型具有安全环保等优势,本文概述了水基预涂型密封胶的国内外技术发展概况,主要对水基型预涂微胶囊厌氧锁固密封胶和单组分水基型预涂密封胶的研究、性能及应用情况作了简要的介绍和展望。     

有机硅密封胶在建筑上的应用

概述了建筑业常用的脱醋酸型、脱醇型、脱肟型、脱酰胺型有机硅密封胶的特点,有机硅密封胶在玻璃幕墙装配、门窗装配、石材幕墙装配、中空玻璃密封、路面及机场跑道和停机坪嵌缝中的应用情况,我国有机硅建筑密封胶的生产及市场情况,以及未来的发展机遇及存在问题.     

耐油性单组分酮肟型有机硅密封胶的研制

研究了脱酮肟型有机硅密封胶耐油性的影响因素,比较了不同交联剂、填料对密封胶耐油性的影响。     

有机硅密封胶粘接聚烯烃材料的研究

研究了不同类型的有机硅密封胶对PE、PP材料的粘接性能,结果表明交联剂和界面因素是影响有机硅密封胶粘接性能的主要因素。根据研究结果设计合成自催化交联型有机硅密封胶和有机硅复合密封胶,并研究它们的性能。     

蓖麻油型聚氨酯密封胶

阐述了蓖麻油型聚氨酯密封胶的性能与发展现状 ,分析了各种组分对密封胶性能的影响 ,并预测了此种密封胶的发展方向     

时间对缩合型RTV有机硅密封胶硬度的影响

跟踪检测了缩合型室温硫化(RTV)有机硅密封胶硫化后在标准条件、室内和室外暴露三种环境下24个月的硬度.结果发现,缩合型RTV有机硅密封胶的硬度在硫化12个月之内随时间的延长有增长趋势,室外暴露下增长最大,室内放置时增长次之,标准条件下放置时增长最小;有机硅密封胶的硬度值在硫化6～15个月内有明显变化,随着时间的推移,变化越来越小,一年以后基本趋于稳定;脱醇型双组分有机硅结构密封胶和酸性大板玻璃用有机硅密封胶的硬度增长最小,脱醇型单组分有机硅结构密封胶的硬度增长次之,酮肟型有机硅密封胶的硬度增长最大.     

某型飞机油箱隔舱的密封胶铆

本文叙述了某型飞机油箱隔舱的密封胶铆工艺过程,较详细地介绍了密封胶铆的表面处理,XM-28Ⅱ型密封胶的配制、胶铆工艺及其质量控制方法等。     

国内简讯

国内简讯高强度系列密封胶生产线建成并投产据“化工市场快讯，１９９４，（３６）：１７”报道，最近在山东化工厂建成了国产第一条高强度系列密封胶生产线并投产，其中，聚氨酯型、有机硅型２种密封胶填补了国内空白。这条密封胶生产线的先进技术和设备，分别从瑞士和意...     

Fluorosiloxane sealants for aviation industry

Properties of sealants based on fluorosiloxane oligomers are considered. It is shown that polysibxanes containing the γ-trifluoropropyl radical can be applied in practice as the base for sealants. It is established that the flexibility of the siloxane chain is responsible for high freeze resistance, while large values of the energy of polar-Si-O-bond allow us to obtain materials with high thermal stability. Mechanical and technological properties of fluorosiloxane sealants are reported, and their advantages relative to materials on the basis of organofluoric rubbers are shown. The domains of the applicability of sealants for surface and interjoint sealing are discussed. It is shown that sealants based on fluorosiloxane oligomers are characterized by adequate stability to prolonged action of different fuels and are widely used in the aircraft construction.     

Study of the adhesive strength of Thiokol-based sealant-metal joints

The effect of test conditions on the work of fracture of Thiokol-based sealants containing different dispersed fillers is studied. Carbon black, titanium dioxide, and hydrophobized natural chalk are used as fillers. The influence of an increase in a single defect is estimated to predict the long-term adhesive strength between the Thiokol-based sealants and different materials. The mechanism and the scale of variations in the fracture strength of sealants in the peel regime are considered. The efficiency of the testing procedure for samples with a central defect is shown. Methods to enhance the fracture strength of Thiokol-based sealants under the conditions of combined stress are discussed.     

聚氨酯密封剂改性方法研究进展

介绍了近年来国内外在提高聚氨酯(PU)密封剂的力学性能、粘接性能、耐候性和施工性等方面的研究进展,主要包括通用PU密封剂的改性、SPU(端硅烷基PU)密封剂的改性和PU密封剂纳米改性等方面的内容,并展望了PU密封剂未来的研究重点和发展前景。     

Effect of filler on the compression set,compression stress–strain behavior,and mechanical properties of polysulfide sealants

In this work, investigations were made on the mechanical properties, stress–strain behavior during compression, swelling and compression set properties of polysulfide sealants at different carbon black and silicon dioxide loadings, and dynamic mechanical thermal analysis was also presented. The results reveal that carbon black filler indeed has significant effects on reinforcing mechanical properties of polysulfide sealants. Increasing carbon black loading improves the tensile strength of sealants promptly, but compression performance increases slowly. The simultaneous use of carbon black and silicon dioxide filler in polysulfide sealants hardly changes the tensile strength of sealants, whereas the ultimate elongation and compression performance of sealants are enhanced remarkably. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Development of an electrochemical impedance spectroscopy sealant test: II. Conductive sealants

Distinguishing between sealants and providing laboratory prognostic tools is essential for qualifying new sealants. Current test methods do not provide adequate discrimination between sealants. A laboratory test based on electrochemical impedance spectroscopy (EIS) supplemented by adhesion strength measurements and examination of sealed, bimetallic surfaces is an approach for discriminating between sealants. This approach gives an early indication of sealant performance so that suitable materials can be chosen for aircraft and other applications. Sealant specimens (three conductive sealants) underwent hot-salt-water exposure followed by EIS inspection, pull strength measurements, and visual inspection. Several specimens exhibited a temporary loss of conductivity during exposure. The maximum low-frequency impedance was correlated to both corrosion inside the sealant ring and pull strength.     

聚氨酯密封胶的研究进展

概述了近年来国内聚氨酯密封胶及端硅烷基聚氨酯密封胶的研究开发进展。     

国内聚氨酯密封胶研究进展

介绍了国内在传统单组分湿固化密封胶、硅烷改性单组分密封胶、蓖麻油基及丁(腈)羟聚氨酯双组分密封胶提高性能方面的最新研究进展。     

木粉填充中空玻璃密封胶条的研制

为降低中空玻璃密封胶条的生产成本,用不同粒径及表面处理的木粉填充再生丁基橡胶来制备密封胶条。力学性能测试结果表明,密封胶条的强度随木粉粒径的增大先增大后减小。红外光谱分析说明,经表面处理后的木粉中含有硬脂酸,木粉表面的羟基可能与硬脂酸发生了酯化反应;密封胶条的剪切强度随处理剂浓度的增大而减小,可塑度先减小后增大;剪切强度和平衡转矩随木粉含量的增加而增大。因此,采用粒径为180μm、3％的硬脂酸乙醇溶液处理的木粉填充制备的密封胶条性能较好,且木粉可以大量填充。     

Development of an electrochemical impedance spectroscopy sealant test: I. Nonconductive sealants

Distinguishing between sealants and providing laboratory prognostic tools is essential for qualifying new sealants. Current test methods do not provide adequate discrimination between sealants. A laboratory test based on electrochemical impedance spectroscopy (EIS) supplemented by adhesion strength measurements and examination of sealed, bimetallic surfaces has been developed to give an early indication of sealant performance. Specimens using one of two different nonconductive sealants underwent hot-salt-water exposure followed by EIS measurements, pull strength measurements, and visual inspection. Defective sealant bonded specimens were readily detected by EIS. Absorption of moisture by the sealants was also detected and quantified.     

聚硫中空玻璃密封胶的性能及生产工艺

概述了中空玻璃密封胶的性能要求，及现有各种中空玻璃密封胶的特性。介绍了聚硫中空玻璃密封胶的配方组成和生产工艺，并就其性能特点与其他密封胶进行了比较。概述了中空玻璃密封胶的发展趋势。