共查询到19条相似文献,搜索用时 156 毫秒
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纤维增强酚醛树脂基复合材料具有易成型、加工周期短和隔热性能好等优点,可用作烧蚀型热防护材料。本文对热熔胶膜法制备的高硅氧/硅硼改性酚醛预浸料及其复合材料进行了研究。硅硼改性酚醛树脂具有优异的热稳定性,氮气气氛下,800℃残碳率高达75.3%。高硅氧/硅硼改性酚醛预浸料的百分流动度、挥发份和树脂含量分别为21.3%、5.7%和40.2%。对比溶液法制备预浸料成型的层压板,采用热熔胶膜法制备的高硅氧/硅硼改性酚醛复合材料层压板的弯曲强度和层间剪切强度分别提高了56.2%和22.1%。氧乙炔线烧蚀率和质量烧蚀率分别为0.0498mm/s和0.0506g/s。高硅氧/硅硼改性酚醛复合材料优异的耐烧蚀性能有助于降低热防护材料的厚度,减轻火箭、导弹等的总体质量,对提高武器装备的性能具有重要的意义。 相似文献
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以氰酸酯为基胶,聚硼硅氮烷前驱体为固化剂,复配相应的填料,制备了氰酸酯基耐高温胶粘剂。研究了聚硼硅氮烷用量对氰酸酯固化特性、固化产物的结构变化及固化物热稳定性的影响。研究结果表明:与传统的氰酸酯胶粘剂相比,聚硼硅氮烷催化氰酸酯的固化温度降低了50~100℃;聚硼硅氮烷可以催化氰酸酯在150℃低温固化,20份聚硼硅氮烷催化氰酸酯固化物T5%最高达到476.3℃。以此为基础制备的耐高温胶粘剂的室温粘接强度最高为16 MPa,400℃老化3 h后粘接强度仍达到12 MPa,表明该胶粘剂具有较好的粘接性能和耐老化性能。本研究制备的胶粘剂凭借较低的固化温度、良好的粘接性能和耐温性,有望用于航空、航天和电子等行业。 相似文献
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以聚磷酸铵、季戊四醇、尿素为阻燃体系,聚酯树脂为基料,加入不同掺量的硅灰,制备硅灰改性膨胀型阻燃剂.通过锥形量热仪、扫描电子显微镜及热重分析仪,对硅灰改性膨胀型阻燃剂的阻燃性能、微观形貌及阻燃机理进行分析,确定最佳硅灰掺量.结果表明:硅灰掺量为2 wt%时样品的阻燃效果最佳,其可使热释放速率峰值和平均热释放速率值最小,火焰强度最低,耗氧量最少,二氧化碳释放量最少;分析样品燃烧后的微观形貌可知硅灰有助于形成更加致密平滑的炭层,其中硅灰掺量为2 wt%时炭层结构最致密完整;热重结果表明硅灰改性膨胀型阻燃剂具有耐高温性,即硅灰的加入能有效降低失重温度,减少试样质量损失,提高其阻燃性能. 相似文献
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采用正硅酸乙酯(ETOS)与硼酸(H3BO3)反应,合成了聚硅硼氧烷(SiOB),再将制备好的聚硅硼氧烷与环氧树脂(EP)进行缩合反应,制备出聚硅硼氧烷改性的环氧树脂,选用低分子聚酰胺650为固化剂进行固化,实验表明工艺可行。通过红外光谱对EP、SiOB及改性后的环氧树脂(SiBP)进行分析和表征,用DSC对改性后的产物进行热力学性能考察,并利用SEM对改性前后的环氧树脂固化物的断截面进行微观检测。研究结果显示,当SiOB加入量为EP的24%~32%(质量分数)时,所制备的环氧树脂涂料具有优异的机械性能、耐热性能及疏水性。 相似文献
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采用固-液吸附及熔融挤出相结合的方法制备一种新型的栽银煤/LLDPE抗菌复合材料(ACCPE).利用现代分析测试手段如IR、XRD、SEM对制备的复合材料进行表征.探讨复合材料的机械性能、流变性能、Ag~+释放特性及抗菌性能.结果表明:复合材料具有良好的机械性能、加工性能和抗菌性能,并且在大肠杆菌的抗菌实验中,Ag~+与煤显示出良好的加合作用. 相似文献
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以聚硼硅氮烷(PSNB)、N-乙烯基吡咯烷酮(NVP)为原料,由过氧化二异丙苯(DCP)引发自由基共聚合反应,制备了聚硼硅氮烷(PSNB/NVP)杂化树脂。采用差示扫描量热仪、热失重仪、红外光谱仪、平板流变仪等对杂化树脂的热性能、固化过程、流变行为等进行测试。结果表明,随着PSNB与NVP的质量比的提高,杂化树脂的热稳定性升高,PSNB与NVP质量比为20/80的杂化树脂在热质量损失率达到为5%时的温度较聚N-乙烯基吡咯烷酮提高近200℃;由杂化树脂高温裂解可得到硅硼碳氮多孔陶瓷,其孔尺寸及分布极不均匀。 相似文献
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水基脱模剂因其优异的性能而得到了广泛的应用,以白油、废机油和二甲基硅油为基础原料,选取Span80和OP-10的组合作为复合乳化剂,配制了一种铝合金压铸用水基脱模剂,该脱模剂具有良好的稳定性和高温成膜性,对铝合金无腐蚀,且将废机油加以利用,变废为宝,具有环境友好型的特点。 相似文献
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《Ceramics International》2022,48(6):8012-8024
When applying an additional coating method to fabricate micro-nano hierarchical structure required for superhydrophobic function on glass surface, the hierarchical structure does generally not have good abrasion resistance, due to the weak adhesion between coating and glass surface. However, glass itself is a material with good abrasion resistance. A micro-nano hierarchical structure with honeycomb-shaped micro-armor protection on glass surface by a two-step hydrothermal corrosion method has been constructed: the first step of hydrothermal corrosion in water to construct micro-armor structure, and the second step of hydrothermal corrosion in sodium citrate aqueous solution to fabricate micro-nano hierarchical structure. The advantages of this new method are: the treatment process is simple, and there is no need to apply additional coatings. The micro-nano hierarchical structure constructed on glass surface by this method has a great abrasion resistance. After 1,000 cycles of abrasion under harsh conditions, the nano-structure on glass surface can still be remained intact. It provides a new method for fabricating abrasion-resistant micro-nano hierarchical structure on glass surface, as well as a new approach to the preparation of abrasion-resistant superhydrophobic glass. 相似文献
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分析了高氯离子、高电导率水源作为循环冷却水系统补水的特点及对循环水系统的影响。缓蚀和阻垢实验结果表明,ECH绿色环保整体解决方案中无磷水处理剂完全可以有效控制系统的腐蚀、结垢和微生物滋生。经过一年的不断优化和工业运行,在高浓缩倍数的情况下,系统运行状况良好。 相似文献
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以羟基亚乙基二膦酸(HEDP)、铵盐、卤化剂为原料合成具有缓蚀、阻垢、杀菌多功能的水处理剂N-氯代氨乙基二膦酸,采用傅里叶红外光谱、~(13)C-核磁共振谱、电化学极化、旋转挂片腐蚀试验、静态阻垢试验、平皿计数法异养菌杀灭性能评价等方法进行了样品分析与性能测试.结果表明.合成的产品单剂在20~40 mg/L下缓蚀阻垢性能优于HEDP,并具有较好的杀菌性能. 相似文献
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The effect of small P2 O5 additions on the acid corrosion behavior of lead silicate glass was studied at 22°C. Crystals of penta-lead phosphosilicate, a phase heretofore synthesized only by high-temperature melt techniques, formed on the surface of the phosphate-doped glass during the corrosion process. No crystals were observed to form on the pure lead silicate glass. Crystallization appears to result from the controlled release of phosphorus and lead at the glass surface and/or from the reactive catalytic properties of a silica gel surface film. Apparent lead diffusion rates into the acid solution for the phosphate-doped lead silicate glass are much less (by a factor of 11,3) than for the pure lead silicate glass. Application of these findings is suggested in two areas: formulation of low cation-release glass and glaze compositions and the synthesis of high-temperature phases in aqueous solution at ambient temperatures. 相似文献
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PASP阻垢缓蚀剂缓蚀机理研究 总被引:4,自引:2,他引:2
绿色化是21世纪水处理药剂的发展方向,以聚天冬氨酸(PASP)代表的绿色水处理剂从而成了研究的热门.目前对有机阻垢缓蚀剂缓蚀的机理研究还处于初步的假说阶段.文章采用尿素和马来酸酐为原料合成PASP,其平均分子量可达10000以上.通过测量PASP在不同pH、温度、时间,以及与无机缓蚀剂进行组合后的年腐蚀率和根据实验中的一些现象,对PASP的缓蚀机理进行了一些讨论. 相似文献
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Waterborne acrylic emulsions modified with organic siloxanes and aziridine crosslinker were synthesized and applied as coating of controlled release fertilizer. The free films were characterized and th... 相似文献
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Stress Corrosion and Static Fatigue of Glass 总被引:6,自引:0,他引:6
Stress corrosion cracking of six glasses was studied using fracture mechanics techniques. Crack velocities in water were measured as a function of applied stress intensity factor and temperature, and apparent activation energies for crack motion were obtained. Data were consistent with the universal fatigue curve for static fatigue of glass, which depended on glass composition. Of the glasses tested, silica glass was most resistant to static fatigue, followed by the low-alkali aluminosilicate and borosilicate glasses. Sodium was detrimental to stress corrosion resistance. The crack velocity data could be explained by the Charles and Hillig theory of stress corrosion. It is probable that stress corrosion of glass is normally caused and controlled by a chemical reaction between the glass and water. 相似文献