共查询到20条相似文献,搜索用时 792 毫秒
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大分子植酸-聚有机硅倍半氧烷的合成及性能 总被引:1,自引:0,他引:1
采用溶胶-凝胶方法, 无需小分子酸催化剂, 利用硅烷化植酸的反应活性和酸催化活性, 与硅烷单体共水解缩聚, 在聚有机硅倍半氧烷分子链上原位接枝植酸, 合成了分子量大于50000的大分子植酸-聚有机硅倍半氧烷. 用GPC, 13C NMR, 29Si NMR, XPS, Raman光谱, SEM及电化学测试等分析手段进行表征, 对比不同酸催化植酸-聚有机硅倍半氧烷(PAP), 单宁酸-聚有机硅半氧烷(TAP), 盐酸-聚有机硅半氧烷(HCP)的结构和性能, 发现植酸-聚有机硅倍半氧烷上的螯合基团与金属表面的活性基团反应而键合, 在金属表面形成致密的保护膜, PAP与TAP和HCP比较具有优异的防腐性能. 相似文献
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本文研究了含羧基聚有机硅氧烷——PEO复合物与LiCF_3SO_3复合膜的离子传导性能。实验结果表明,利用PEO与含羧基聚有机硅氧烷复合的方法能进一步提高含羧基聚有机硅氧烷—Li~+固体电解质膜的离子传导性。此复合膜在室温下的离子导电率可达10~(-5)S cm~(-1)。本文还研究了复合膜中所用PEO的分子量、PEO用量,LiCF_3SO_3含量、交联剂用量及温度对复合膜离子传导性的影响。 相似文献
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以不同分量的α,ω-双(γ-氨丙基)聚二甲基硅氧烷预聚物为软段,分别以聚芳 酯、聚酰亚胺为硬段合成了嵌段长短不同及含量不同的聚有机硅氧烷-聚芳酯嵌段共聚物和聚有机硅氧烷-聚酰亚胺嵌段共聚物。 相似文献
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有机硅氧烷预聚体的合成及其在化学固沙中的应用 总被引:1,自引:0,他引:1
以甲基三乙氧基硅烷为反应物,在盐酸催化下水解缩合,合成无色透明粘稠的液体有机硅氧烷预聚体,IR和1H NMR表征证实其为目的产物;当有机硅氧烷预聚体与工业乙醇的体积比为1∶1,以质量分数0.60%的NaOH-CH3OH溶液为固化剂,加入该溶液0.05 mL,在30 ℃,预聚体交联固化时间为9 min;在50 ℃,预聚体交联固化时间为4 min;首次将有机硅氧烷预聚体,或它与聚乙烯醇(PVA20-88)的混合物用作化学固沙剂,形成的固结层具有较好的耐水性和较高的抗剪强度;当PVA20-88与有机硅氧烷预聚体的质量比为1∶4时,粘聚力达到483.7 kPa,内摩擦角为68.39°,在160 h的紫外光照射下,具有很好的耐老化性。 相似文献
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在UV照射下,用含巯基的有机硅化合物与聚甲基乙烯基硅氧烷加成硫化虽有专利报道,但该反应体系是以二苯甲酮类化合物作为光敏剂。当我们进行这方面研究时,发现二苯甲酮与有机硅氧烷预聚物相容性差,从而影响光加成反应的速度。为了改善光敏剂与有机硅预聚物的相容性,本文合成了具二苯甲酮基团的环状有机硅氧烷及其高聚物作为光敏剂。 相似文献
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Zbigniew Jedliaski Danuta Sek 《Journal of polymer science. Part A, Polymer chemistry》1969,7(9):2587-2604
A series of aromatic polyesters has been prepared by low-temperature solution polycondensation of derivatives of dihydroxydinaphthyl or dihydroxydinaphthylmethane with terephthaloyl chloride. The chemical, physical, and thermal properties of some polyesters have been investigated. Some of the polyesters obtained have high melting temperatures (340–420°C) and very good thermal resistance. In spite of their high melting temperatures some polymers give solutions in organic solvents which make it possible to produce films and coatings with good dielectric and mechanical properties and with a relatively high thermal resistance. 相似文献
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St. S. Solntsev 《Russian Journal of General Chemistry》2011,81(5):992-1000
High-temperature composite materials and coatings developed in the RIAM, specifically construction composite materials with
glass, glass-ceramic, and ceramic matrices, for use at 700–1500°C, ceramic composites on the basis of poly-carbosilanes, erosion
resistant coatings with the effect of thermal control for heat shield systems of perspective aerospace technics, are reviewed.
These coatings combine a complex of properties: high radiating capacity, phase stability, thermal shrinkage resistance, resistance
against acoustic, vibration, atmospheric factors, etc. Technological coatings to protect steels and Ti and Ni alloys during
heat treatment and isothermal and hot die forging are developed. New type enamels, pasts, thick-film electric heaters, etc.,
are described. 相似文献
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The coating performance of adipic acid modified and methacrylated bisphenol- A based epoxy oligomers
In the present work adipic acid modified and methacrylated bisphenol A based epoxy resins were prepared. The structures of oligomers were characterized by FT-IR. UV curable clear coatings were applied on aluminum substrates. The physical and mechanical properties of UV-cured coatings such as gel content, solvent resistance, hardness, gloss, flexibility and tensile tests were examined. In addition, the thermal behavior of coatings was also evaluated. It is observed that the tensile properties and thermal stabilities of modified epoxy methacrylate coatings mainly depend on the adipic acid content. The best results were obtained with 5 wt% adipic acid modification. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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To improve the thermal resistance of a coating, a polyurethane binder has been synthesized with the use of hydroxyethylated diphenylolpropane. The influence of the catalyst concentration, solvent nature, and structure and molar ratio of the initial reagents on the properties of the coatings is studied. The composition, corresponding to the polyurethane coating with high physicomechanical properties combined with thermal and chemical resistance, is established. 相似文献
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Yusuf Mülazim Memet Vezir Kahraman Nilhan Kayaman Apohan 《Journal of Sol-Gel Science and Technology》2011,59(3):613-620
10B containing organic–inorganic hybrid coating material based on a UV-curable formulation was prepared via anhydrous sol–gel
technique. UV curable coatings were applied on Plexiglas (PMMA) substrates. The molecular structure of the coating material
was analyzed by ATR-FTIR spectroscopy technique. The characterization of the UV-curable coating was evaluated by various techniques
such as gel content, abrasion resistance, chemical resistance, pencil hardness, pendulum hardness, MEK rubbing test, contact
angle, cross-cut test, gloss, transmittance test, neutron absorption, Limiting Oxygen Index and stress–strain tests. Hybrid
coatings showed a significant enhancement in radiation shielding properties. The thermal behavior of coatings was also evaluated.
It is observed that the thermal stability of coatings mainly depends on their boron and silicate contents. Results of all
analysis conducted on hybrid films, and coatings were discussed. 相似文献
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In this study, novel bio-based hydroxyl-end-capped (co)polyesters from dimethyl-2,5-furandicarboxylate (DMF), 2,3-butanediol, and a variety of comonomers viz. glycerol, pentaerythritol or trimethylolpropane are prepared using a solvent-free, bulk polycondensation technique. Extensive molecular and thermal characterization was performed to elucidate the properties of these materials. The materials showed suitable properties for solvent-borne coating applications in terms of their molecular weight, functionality and thermal characteristics, and coatings were prepared using the isocyanurate of hexamethylene diisocyanate as a cross-linker. The resulting coatings, having thicknesses between 30 and 55 μm, were hard but rather brittle. All the coatings have good solvent resistance, pointing to sufficient network formation. It is clear that the presented DMF-based polyesters show promise as bio-based coating resins. 相似文献
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The choice of charring agent is one of the major issues for solvent‐free fireproof coatings. The effects of processing method and charring agent on the thermal insulation and fire resistance of the coatings were investigated in simulated fire scenarios. Dipentaerythritol (DPER), triazine agent (CFA), and pentaerythritol phosphate (PEPA) were compared as charring agent, and the thermal, combustion, fire resistance, and charring behaviors in different fire scenario were characterized for the fireproof coatings. Compared with high‐speed dispersing equipment, kneading processing equipment is favorable for improving the thermal stability and fire resistance of the coatings, because the stronger shearing force has promoted mixing and dispersion of the ingredients in solvent‐free fireproof coatings. As for charring agents, it is found that the fireproof coatings containing CFA or PEPA show better thermal and flame‐retardant performances. More residue was observed under nitrogen atmosphere in thermogravimetric analysis, less heat and smoke were released in cone calorimetry test. However, during the high temperature fire resistance test, their char layers were prone to delaminate while DPER‐containing coatings produced intact and stronger char layer with better heat insulation. For practical applications, the coating formulations need to be optimized to achieve both fire resistance and flame retardancy. 相似文献
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采用水热电泳沉积法和固相渗透法在C/C复合材料表面制备了MoSi2/SiC复合抗氧化涂层。分别采用X射线衍射、扫描电子显微镜和等温静态氧化实验对复合涂层的晶相组成、显微结构和抗氧化性能进行了表征。主要研究了水热电泳沉积温度对MoSi2外涂层显微结构及高温抗氧化性能的影响,重点分析了涂层试样在1500℃和1630℃下的静态氧化行为及失效机理。结果表明:外涂层主要由MoSi2和少量MoO3晶相组成。外涂层的致密程度、厚度及抗氧化性能随着水热温度的升高而提高。MoSi2/SiC复合涂层具有较好的抗氧化和抗热震能力,在1 500℃下有效保护基体320 h同时经历17次1 500℃与室温之间的热循环后,氧化失重率仅为1.07%;在1630℃下氧化88 h后失重率为2.17%。复合涂层在1 630℃下的氧化失效主要是由于经过长时间氧化后SiO2玻璃膜层不能及时有效填补涂层中的缺陷,涂层试样在热循环过程中产生了贯穿性的孔洞导致的。 相似文献
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Novel high temperature-resistant coatings with high mechanical strength and thermal-insulating performance were prepared with poly(ether nitrile ketone)(PPENK) resin as matrix and hollow glass microspheres(HGMs) as thermal-insulating filler. The corresponding mechanical and thermal-insulating study indicated that the mechanical properties of the coatings decreased with the increase of HGM content,and were improved after surface modification of HGM by KH570 resulting in enhancement of interaction between HGM and PPENK resin. The thermal conductivity of HGM/PPENK thermal-insulating coating decreased with the increase of HGM content and coating thickness, along with the decrease of the true density. It also showed slight increase trend due to HGMs surface modification. The HGM/PPENK coating filled with modified HGMs showed better thermal resistance than that of unmodified HGM/PPENK coating. The thermal decomposition temperature at 5%weight loss of the coating containing modified HGMs was 10 °C lower than that of pure PPENK, and 40 °C higher than that of neat HGM/PPENK coating. The coating exhibited commendable appearance after 400 °C for 30 min. The merits of HGM/PPENK-based thermal coatings obviously demonstrated promising prospect in thermal protection fields. 相似文献