共查询到18条相似文献,搜索用时 111 毫秒
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以二缩水甘油乙醇胺(DGEEA)作为端-NCO型PU(聚氨酯)预聚体的封端剂,合成了具有高反应活性的GAPU(端缩水甘油胺型聚氨酯)。采用红外光谱(FT-IR)法对其结构进行表征,应用滴定分析法确定了中间产物和目标产物的羟值、环氧值和-NCO值,考查了不同柔性链段对产品力学性能的影响。结果表明:间苯二甲胺(m-XDA)作为EP/GAPU体系的固化剂,具有相对最好的固化效果;当多元醇为聚四氢呋喃醚二醇(PTMG-1000)时,PTMG-1000-GAPU/m-XDA体系的综合力学性能较好,其剪切强度为8.28 MPa,剥离强度为1.52 kN/m。 相似文献
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以甲苯二异氰酸酯、聚丙二醇为主要原料,制得异氰酸酯基(—NCO)封端的聚氨酯预聚体(NCOPUR),然后利用缩水甘油进行再封端,制得缩水甘油封端聚氨酯(GAPUR)。采用FTIR对GAPUR的结构进行表征,用DSC分析GAPUR的微相分离,并研究了以间苯二甲胺作为固化剂固化GAPUR/环氧树脂(EP)复合体系的力学性能,利用在线FTIR监测复合体系的固化过程,用SEM观察固化体系拉伸断面的表面微观形貌。结果表明,间苯二甲胺在60℃固化2 h,体系可完全固化;GAPUR的加入显著提高了EP的韧性。 相似文献
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3-氯-1,2-丙二醇及缩水甘油的合成研究 总被引:2,自引:0,他引:2
以甘油为原料,在无水乙酸的作用下与HCl反应合成出3-氯-1,2-丙二醇,优化了3-氯-1,2-丙二醇的合成工艺,得到适宜的反应条件为:反应温度90℃,反应时间4 h,催化剂用量5%(w/w),HCl气体流速20 L/h。然后利用制备的3-氯-1,2-丙二醇在二氯甲烷溶剂中与强碱性阴离子交换树脂作用合成了缩水甘油,最佳反应时间为1 h。产物分别通过GC和IR进行了鉴定,3-氯-1,2-丙二醇和缩水甘油的产率分别可达到84.6%和89.6%。 相似文献
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Novel polyurethane insulating coatings were prepared from the reaction of glycerin‐terminated polyurethane prepolymers (GPUPs) and a blocked isocyanate curing agent (BIC). The GPUPs were prepared from the reaction of one equivalent of polycaprolactone polyol (CAPA 210) with an excess amount of 4,4′‐methylene bis(phenyl isocyanate) (MDI) and subsequent reaction of the NCO‐terminated polyurethane with glycerin. The BIC was prepared from the reaction of trimethylol propane (TMP), toluene diisocyanate (TDI) and N‐methylaniline (NMA). The polyols and curing agent were characterized by conventional methods while the curing condition was optimized via gel content measurements. The curing kinetics of the polyurethane coating were investigated and the kinetic parameters derived. The crosslink densities of the samples were determined via the equilibrium swelling method, using the Flory–Rehner equation. The relationships between the crosslink density and the electrical, physical, mechanical and dynamic mechanical properties of the coatings were also studied. Copyright © 2005 Society of Chemical Industry 相似文献
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Sriram Venkataramani Tharanikkarasu Kannan Ganga Radhakrishnan 《Polymer International》2006,55(11):1209-1214
1‐Vinylimidazole‐terminated telechelic polyurethanes were prepared from 1‐vinylimidazole and bromine‐terminated polyurethane. This vinyl‐terminated telechelic polyurethane (VTPU) and methyl methacrylate were polymerized in the presence of benzoyl peroxide to prepare novel AB crosslinked polymer networks (ABCPs). These were characterized by spectral, thermal and mechanical studies. The absence of the characteristic peak of vinyl group in infrared spectra of ABCP films confirms the occurrence of crosslinking. Static mechanical testing showed that the tensile strength of ABCP increases with increasing poly(methyl methacrylate) content. Dynamic mechanical studies revealed that ABCPs, at equal compositions of VTPU and methyl methacrylate, show good damping properties. Copyright © 2006 Society of Chemical Industry 相似文献
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Katsuji Matsunaga Kazuko Nakagawa Satoshi Sawai Osamu Sonoda Masahiro Tajima Yasuhiko Yoshida 《应用聚合物科学杂志》2005,98(5):2144-2148
Un‐ionized polyurethane was obtained by the reaction of an isocyanate‐terminated urethane prepolymer, which was synthesized from 4,4′‐diphenylmethane diisocyanate and poly(oxytetramethylene)‐α,ω‐glycol, with 2,2‐bis(hydroxymethyl)propionic acid. A carboxylate‐based polyurethane anionomer was then derived from the polyurethane by the use of the sodium, potassium, or magnesium salt of acetic acid as a neutralizer. The ionomerization resulted in the following changes in the characteristics of the polyurethane: (1) an increase in the tensile strength, (2) a decrease in the glass‐transition temperature, (3) an increase in the wettability and hygroscopicity with respect to water, and (4) susceptibility to thermal decomposition. A sulfonate‐based polyurethane was also synthesized for comparison with the carboxylate‐based polyurethane. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2144–2148, 2005 相似文献
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分别合成了以苯基异氰酸酯封端和以脂环族异氰酸酯封端的聚氨酯预聚物,考察了分散温度和溶剂对两种不同类型的聚氨酯预聚物的乳液和涂膜性能的影响。分散温度和溶剂改变了分散过程的流变性能,从而对最终乳液性能产生影响。而不同类型的聚氨酯预聚物由于封端异氰酸酯的活性不同,它们的最佳分散温度也不同。实验优化了两种聚氨酯预聚物的溶剂用量和分散温度,得到粒径小于50nm的稳定乳液,涂膜性能优良。 相似文献