京沪高铁桥面喷涂聚脲常见质量缺陷与应对措施

结合京沪高铁喷涂聚脲防水层的施工实践,从施工角度分析总结了喷涂聚脲施工常见的鼓泡、针孔、分层等质量缺陷产生的原因及其应对措施,指出做好基面处理是减少缺陷发生的关键,探讨了修补砂浆、基面针孔刮涂腻子、底涂三种基面处理材料的选用.同时对聚脲的快速固化等特性进行了客观分析,并介绍了低温施工的应对措施.     

高固含量聚脲多元醇对聚氨酯泡沫性能的影响

以自制高固含量低粘度聚脲多元醇为主要原料制备了高回弹聚氨酯软泡,研究了对泡沫的密度、回弹率、压陷硬度、水平燃烧速率和氧指数等性能的影响。结果表明,高固含量聚脲多元醇可以提高泡沫的热稳定性,使高回弹聚氨酯软泡有更好的耐燃性,甚至可离火自熄;对软泡的密度影响不大,对泡沫的回弹率和压陷硬度都有不同程度的影响。     

聚氨酯和聚脲的傅里叶变换红外透射光谱的研究

用傅里叶变换红外透射光谱研究了溶液聚合的四种模型嵌段共聚物——聚氨酯-氨酯、聚脲-氨酯、聚氨酯-脲、聚脲-脲——在硬段微区和相界面区氢键的情况,并与衰减全射谱在分析这些模型嵌段共聚物时的情况进行了对比。     

A model for microencapsulation in polyurea shell by means of interfacial polycondensation

A quasi-steady state model, based on two parallel modes of diffusion and a polycondensation reaction at the inside surface of a microcapsule, is formulated to compute the time of this microencapsulation process. The predicted times of encapsulation are in agreement with observed values reported in patents. It is also shown that, for small shell thickness, the process is reaction-controlled.     

聚脲喷涂弹性体的研制

对非端氨基聚醚的聚脲喷涂弹性体配方进行了研究,考察了聚丙二醇（PPG）软段、硬段含量以及扩链剂对弹性体性能的影响,制备出适用于混凝土桥梁和水处理池的防水防渗层材料,也可用于机械设备内衬。     

喷涂聚脲弹性体耐水性能的研究

以不同种类多元醇与二苯基甲烷二异氰酸酯（MDI）和液化MDI合成预聚物作为A组分,端胺基聚醚、胺类扩链剂为R组份,制成喷涂聚脲弹性体。讨论了多元醇种类及其相对分子质量、A组分的NCO含量、扩链剂等对喷涂聚脲弹性体耐水性能的影响。结果表明,由二聚体聚酯二醇制得的喷涂聚脲弹性体耐水性能最好,其次是聚四氢呋喃多元醇,聚氧化丙烯醚二醇的耐水性最差;随着多元醇相对分子质量的增加,聚氧化丙烯醚二醇和聚四氢呋喃醚二醇的耐水性提高,而二聚体聚酯二醇的耐水性能变化不大;A组分的NCO含量增加,耐水性提高;不同扩链剂的耐水性有很大差异,依次为3,3’．二氯4,4’-二苯基甲烷二胺〉二乙基甲苯二胺〉3,5-二甲硫基甲苯二胺〉4,4’-双仲丁胺基二苯基甲烷。     

喷涂聚脲弹性体专用设备--施工车

重点介绍喷涂聚脲弹性体技术在异地、远程施工中所必须配备的专业施工车及其内部配置。     

聚脲防腐涂料概述

阐述了聚脲的定义、组成和发展历程，简介了聚脲涂料在防腐方面的应用和突出优点。     

喷涂聚脲弹性体在混凝土防腐工程中的应用

简要介绍了喷涂聚脲弹性体材料的独特性能及其优点,结合具体防腐工程实际对喷涂聚脲弹性体进行了设计,详细阐述了喷涂聚脲弹性体施工技术及其配套措施(基层处理、安全措施)。     

Synthetic polyurea extreme‐pressure greases

This paper describes the preparation of synthetic polyurea greases and evaluates their performance. The polyurea greases were prepared in situ by reacting diisocyanate with monoamines and ethylene diamine in the presence of a synthetic base oil (polyalphaolefin). Two different extreme‐pressure (EP) additives blended with the prepared polyurea greases were evaluated for their EP activity in four‐ball and Timken tests. The additivated greases gave higher loads, and higher values of weld load in the four‐ball test as compared to the polyurea grease without additive. The blended greases were also found to pass rust, corrosion, oxidative stability, and shear stability tests. The topography of the wear‐scar surfaces was investigated using scanning electron microscopy.