共查询到20条相似文献,搜索用时 125 毫秒
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为改善单组分室温硫化(RTV)硅酮密封胶强度较低的缺点,采用γ-氨丙基三乙氧基硅烷(KH-550)对硫酸钙晶须进行表面湿法改性。将改性CaSO4晶须加入RTV硅酮密封胶中,制备了高性能的RTV硅酮密封胶。阐述了KH-550改性CaSO4晶须的机理,考查了KH-550用量、改性温度以及改性时间对改性效果的影响。探讨了改性CaSO4晶须对RTV硅酮密封胶工艺性、硬度以及力学性能的影响。结果表明,当m(KH-550)=3%、改性温度90℃、改性时间30min时改性效果最佳。改性CaSO4晶须的活化指数可达到80%以上。CaSO4晶须的添加量越多,RTV硅酮密封胶的挤出性越差;当改性CaSO4晶须质量分数8%时,对密封胶硬度的改性效果最佳。当改性CaSO4晶须质量分数为4%~5%时,制备的胶粘剂拉伸强度、剪切强度和断裂伸长率最优。 相似文献
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硫酸钙晶须对环氧胶粘剂性能的影响 总被引:15,自引:1,他引:14
本文初步研究了硫酸钙晶须对环氧树脂胶粘剂性能的影响,简要分析了硫酸钙晶须对环氧树脂胶粘剂增强和增韧的机理,得出了硫酸钙晶须增强环氧树脂胶粘剂体系基本组分的适宜配量,为环氧树脂增强和增韧提供了一种物理方法。 相似文献
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采用TiO2粒子和二氧化钛-甲苯二异氰酸酯(TiO2-TDI)粒子对聚氨酯胶粘剂进行了改性处理,研究了不同添加量的改性粒子对聚氨酯胶粘剂硬度、羟基指数、拉伸剪切强度和表面形貌的影响。结果表明,改性聚氨酯胶粘剂的邵氏硬度随着二氧化钛粒子添加量的增加而逐渐增大,而老化1 000 h后,改性聚氨酯胶粘剂的邵氏硬度会随着TiO2粒子添加量的增加而逐渐减小。随着老化时间从0增加至1 000 h,聚氨酯胶粘剂和改性聚氨酯胶粘剂的羟基指数(CI)都会随着老化时间的延长而逐渐增大,且相同老化时间下,PU+0.4%TiO2-TDI的CI指数更小、拉伸剪切强度最大,其次为0.4%TiO2改性聚氨酯胶粘剂。 相似文献
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以页岩提钒中和渣为原料,采用水热法制备硫酸钙晶须,并进行稳定-改性处理,最终制备用于填充塑料的硫酸钙晶须填料。研究了反应温度、反应时间、料浆浓度及助晶剂用量对硫酸钙晶须长径比的影响以及改性剂用量、初始料浆浓度、改性温度及改性时间对硫酸钙晶须改性效果的影响。结果表明,在反应温度为130℃、反应时间为6 h、料浆质量分数为3%、助晶剂六水氯化镁用量为10%的条件下,制备出的硫酸钙晶须长径比达90,但晶须在空气中易水化变粗,长径比降至20以下。在硬脂酸用量为4%、初始料浆质量分数为8%、改性温度为90℃、改性时间为20 min的条件下,制备的硫酸钙晶须填料活性指数达0.72,吸油值为0.278 8 g/g,制得的硫酸钙晶须填料呈棒状或纤维状,表面光滑,结晶度较好,长径比稳定在40~50。结合XRD、SEM、FT-IR分析可知,硬脂酸能有效抑制晶须水化过程,保持晶须晶型及形貌稳定,硬脂酸通过与晶须表面发生化学键链接封闭其亲水活性点而抑制晶须水化。 相似文献
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以硫酸钙晶须、硫酸镁晶须为增强改性剂,高胶粉为增韧改性剂,ABS为主体材料,通过采用熔融混合挤出制得改性ABS复合材料。对该复合材料的力学性能、热性能进行测试,观察了硫酸钙晶须和硫酸镁晶须用量对ABS复合材料的力学性能、热性能的影响,并讨论了相关的增韧增强机理。观察了硫酸钙晶须、硫酸镁晶须/ABS复合材料的微观结构。实验结果表明,在改性ABS材料时,硫酸镁晶须与硫酸钙晶须相比,具有更好的综合力学性能。 相似文献
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硫酸钙晶须/PP/EPDM复合材料的流变行为 总被引:4,自引:0,他引:4
利用Instron 3211型毛细管流变仪研究了硫酸钙晶须/PP/EPDM复合材料的流变行为,讨论了剪切速率、温度、晶须含量对PP/EPDM共混物表观粘度的影响。结果表明,该共混体系属于假塑性流体,硫酸钙晶须在低添加量时对PP有降粘作用;加入30%硫酸钙晶须的PP/EPDM体系,粘流活化能略高于未加晶须的体系,两个体系均为温敏性材料。 相似文献
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Jessica Donate-Robles José Miguel Martín-Martínez 《International Journal of Adhesion and Adhesives》2011,31(8):795-804
Precipitated calcium carbonate filler (PCC) was added to a thermoplastic polyurethane adhesive (TPU). The addition of PCC produced a moderate increase in the rheological and viscoelastic properties of TPU due to the poor dispersion of filler (i.e. found to be clusters) and the weak interactions between the PCC nanoparticles and the polymer chains. The interactions were noticed by ATR-IR spectroscopy by displacement of the bands at 3326, 1729 and 1061 cm−1 to higher wave number of the polyurethane. Furthermore, the first glass transition temperature of the polyurethane was found to decrease by adding PCC filler. The crystallinity of the soft segments in the TPU was decreased by adding PCC because of the disruption of the degree of phase separation in the polymer. The initial adhesive strength in PVC/TPU adhesive/PVC joints increased noticeably by adding PCC filler, the greater the amount of filler in the TPU, the greater the initial adhesive strength found. Finally, the highest final adhesive strength (72 h after joint formation) was obtained in the joint produced with the TPU containing 10 wt% PCC. 相似文献
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CaSO4晶须与EPDM/PP共混型热塑性弹性体复合材料的研究 总被引:11,自引:1,他引:10
研究了CaSO4晶须与三元乙丙橡胶/聚丙烯共混型热塑性弹性体复合材料的物理机械性能、耐热性能、热老化性能、材料的和各向异性、流变性能,考察了复合材料物理机械性能与晶须用量、界面特性、弹性模量等之间的依赖关系。应用SEM观察和DSC热分析以及TG热重分析研究复合材料结构-性能间关系中存在的一些制约机理。 相似文献
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硫酸钙晶须/PP/EPDM复合材料力学性能研究 总被引:13,自引:0,他引:13
采用对硫酸钙晶须进行表面处理和提高PP/EPDM基体树脂极性的方法制得具有良好界面层的硫酸钙晶须/PP/EPDM复合材料。力学性能测试结果表明,硫酸钙晶须可提高PP/EPDM基体的拉伸强度和弯曲强度,通过控制各组分配比可制得韧性和刚度均衡的复合材料。 相似文献
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采用硅烷偶联剂(KH-570)对CaCO3晶须进行表面改性,研究了改性CaCO3晶须对紫外光固化顺丁烯二酸酐-端羟基聚丁二烯改性环氧丙烯酸酯和聚氨酯丙烯酸酯材料性能的影响。结果表明,当CaCO3晶须质量分数为15%时,两种材料的拉伸强度均达到最大值,分别比基体树脂固化材料提高了110%和95%。当CaCO3晶须质量分数为10%时,两种材料的冲击性能、耐磨性能最好,冲击强度比基体树脂分别提高40%和25%,磨损量比基体树脂分别降低91.25%、91.70%。另外,探讨了CaCO3晶须改善材料耐磨性的机理。 相似文献
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Chen-Chi M. Ma Hung-Chung Hsia Der-Shyang Chen Ye-Shiu Li Ming-Shiu Li 《Polymer International》1994,35(4):361-370
Polyurethane adhesives containing the polyether backbone exhibit a good joint strength in cryogenic environments. In practice, many of the commercially available polyurethane adhesive systems contain free or chemically blocked isocyanates which have some limitations. This study presents the synthesis and characterization of a modified polyurethane type adhesive. Glycidol was used to convert the isocyanate-terminated polyurethane prepolymer to glycidylterminated polyurethane prepolymer. A series of glycidyl-terminated polyurethanes, based on polyoxypropylene glycol (PPG) soft segments having different molecular weights, were synthesized and their adhesive properties on aluminium were evaluated. The effect of the soft segment length on adhesion was examined. The adhesive properties at room temperature and cryogenic temperature are in line with the phenomenon observed in dynamical mechanical analysis (DMA) and in the phase separation behavior of the polyurethanes. Differential scaning calorimetry (DSC) was used to assess the phase separation content. An improvement in the adhesive strengths at room temperature is achieved by adding epoxy resins to the glycidyl-terminated polyurethane resins. 相似文献
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A. Torr -Palau J. C. Fern ndez-Garcí a A. C. Orgil s-barcel M. M. Pastor-Blas J. M. Martí n-martí nez 《The Journal of Adhesion》1997,61(1):195-211
Fumed silica is a well-known mineral filler of epoxy and polyurethane adhesives. Although effective, the small particle size and the relative high cost of fumed silicas suggest the need for an alternative filler. In this study, the usefulness of adding a natural hydrated magnesium silicate (sepiolite) as a new filler in solvent-based polyurethane (PU) adhesive formulations has been demonstrated. The rheological and adhesion performance of the sepiolite-filled PU adhesive was compared with that in PU adhesives containing fumed silicas. The addition of a filler to PU adhesives provided an increase in viscosity, imparted thixotropy and pseudoplasticity to the adhesive solution, produced an increase in storage and loss moduli, and improved the rheology of the PU. The mechanical properties of adhesive films were increased by adding filler, mainly with fumed silica. On the other hand, the immediate T-peel strength of roughened or (roughened + chlorinated) styrene-butadiene rubber/PU adhesive joints was greatly improved in filled PU adhesives. The effects produced by adding sepiolite or fumed silica to the adhesives were very similar, although in general more noticeable in fumed silica filled PU due to the formation of hydrogen bonds between the filler and the solvent and/or the polyurethane (in sepiolite-filled adhesives, van der Waals forces seemed to be responsible for the interactions between the filler and the solvent and/or polyurethane). 相似文献
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实验研究磷石膏净化处理方法及化工综合利用新路。在对磷石膏样品进行粒度分布、XRD矿物分析、化学成分分析和SEM形貌分析等物性检测的基础上,利用廉价的碳酸氢铵和氨水及工业副产盐酸,对磷石膏进行净化处理,去除杂质提纯得到硫酸钙,副产氯化铵并回收二氧化碳。以磷石膏提纯得到的硫酸钙为原料,采用水热法制备硫酸钙晶须,提升磷石膏的利用价值。实验得到磷石膏净化处理和水热法制备硫酸钙晶须的最优化工艺条件,并通过POM与SEM对所得硫酸钙样品和硫酸钙晶须进行形貌分析。结果表明,工艺路线在技术上是可行的,工艺设备和操作条件简单、母液可循环使用、无三废污染,既减轻了环境污染,又降低了生产成本,具有较好的经济效益和社会效益。 相似文献