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本文是单组份湿固化聚醚型聚酯密封胶的合成与研究。该胶由二官能度和三官能度聚醚与TDI反应制成预聚体后再加入多种填料和催化剂制成。讨论了TDI用量,反应温度,聚醚的组成及填料对该胶的影响。 相似文献
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为提升建筑外墙保温板的使用寿命,制备装配式建筑外墙保温板接缝用改性聚醚密封胶,并通过试验分析该密封胶性能。以封端硅烷偶联剂和异腈酸酯基硅烷作为改性剂,聚醚元醇作为基料制备改性聚醚密封胶,应用在装配式建筑外墙保温板接缝中。依据标准测试该密封胶的表观性能,研究养护时间、紫外光照对该密封胶的粘接强度影响,分析催化剂和填料用量对于该密封胶表观性能与拉伸性能影响。试验结果表明,该密封胶表观性能符合标准,养护7 d后粘接性能基本稳定,催化剂用量20%,填料用料30%时表观性与拉伸性能最好。 相似文献
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使用聚醚二元醇等材料实现封端,制备硅烷封端聚醚预聚体,将该预聚体作为基础制备高弹性改性聚醚密封胶。通过试验确定吸附剂用量,分析温度对密封胶弹性影响以及密封胶的固化性能。研究不同湿度下密封胶的吸水率变化,并测试密封胶的粘结性能。试验结果显示,多孔二氧化硅吸附剂能够提升硅烷封端聚醚预聚体性能;密封胶所处环境温度越高,弹性模量呈现下降趋势,弹性恢复率没有出现明显变化;周围环境湿度的增加能够提升密封胶吸水性,使得密封胶不易开裂,养护28 d的密封胶在粘结金属材料和陶瓷材料时密封效果更好,密封性能更高。 相似文献
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氧化钙脱水法合成对羟基苯甲酸酯 总被引:15,自引:0,他引:15
在催化剂作用下,用氧化钙作脱水剂,采用索氏提取器将对羟基苯甲酸与脂肪醇进行回流脱水直接酯化。酯化反应时间仅需3h,产率达94%~96%,同时对影响产率的因素进行考察,确定了最佳反应条件。 相似文献
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In this study, we synthesized poly(hydroxy)urethanes by the polyaddition reaction of bis(cyclic carbonate) and diamine. Bis(cyclic carbonate) was prepared from diglycidyl ether based on bisphenol S and carbon dioxide. Thermal properties and solubilities of the poly(hydroxy)urethanes of five different diamines were compared. The thermal properties of the poly(hydroxy)urethanes depended on the structure of the diamine as well as the structure of the monomer. These poly(hydroxy)urethanes were soluble only in aprotic solvents because of the hydrophilic character of the hydroxy group. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2735–2743, 2001 相似文献
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本文探讨了2-乙酰基-7-甲胺基卓酮与3,4,5-三甲氧基苯甲醛(TMB)等取代芳香醛的羟醛缩合反应。2-乙酰基-7-甲胺基卓酮与TMB、丁香醛、二溴醛等取代芳香醛进行反应分别生成了2-(3,4,5-三甲氧基)肉桂酰基-7-甲胺基卓酮;2-(4-羟基-3,5-二甲氧基)肉桂酰基-7-甲胺基卓酮;2-(4-羟基-3,5-二溴)肉桂酰基-7-甲胺基卓酮等三种尚未见文献报道的新化合物。它们的结构经红外光谱、核磁共振谱及元素分析得以证实。 相似文献
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Silsesquioxane, siloxane, and silmethylene polymers with phenolic hydroxy groups were prepared in order to obtain alkali-soluble organosilicon polymers. These polymers have structures in which the phenol moieties are separated by one carbon from the silicon. The hydroxy groups were protected as methoxy groups in polymerization processes, then were changed into hydroxy groups by a reaction with trimethylsilyl iodide followed by alcoholysis. In the course of discussion on the characteristics of these polymers, silsesquioxane with phenolic hydroxy groups is found to possess excellent properties for matrix resins of alkalidevelopable organosilicon resists, such as O2RIE resistance and heat resistance. 相似文献
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Summary The polyallylation reaction of c-cresol novolac 1 was achieved in polar aprotic solvents with high phenolic hydroxy conversion(>99%) leading to a unique o-allylation product(>99%). When the reaction was carried out in protic solvent, the c-allylation reaction occurred at about 20–30% along with the o-allylation reaction. Additionally, the phenolic hydroxy conversion was less than 85%. These results showed that the regioselectivity of this reaction was mainly governed by the solvents used. The mechanism of this transformation is briefly discussed in terms of the ambident nature of and solvation effects on the counter ions pair of the phenoxide. 相似文献