共查询到18条相似文献,搜索用时 78 毫秒
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以554/504为固化剂,研究了不同固化时间下,F51用量对PVC/F51共混物的微观形貌、力学性能和维卡软化温度的影响。结果表明:①少量的F51在PVC基体中分散比较均匀,F51用量较多时会出现团聚现象;②少量的F51有利于提高PVC/F51共混物的力学性能和维卡软化温度,用量以2~6份为宜;③随着固化时间的延长,PVC/F51共混物的力学性能和维卡软化温度均提高;④固化剂554可进一步提高PVC/F51共混物的拉伸强度和弯曲强度,但会降低缺口冲击强度和维卡软化温度。 相似文献
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以504及554/504分别作为固化剂,采用锥形双螺杆挤出机实现了PVC与环氧树脂的熔融共混,制备了PVC/环氧树脂E51共混物。固化剂用量为环氧树脂E51用量的80%时,研究了环氧树脂E51用量、固化剂组成及固化时间对PVC/环氧树脂E51共混物力学性能及维卡软化温度的影响。结果表明:以504及554/504为固化剂,少量环氧树脂E51(4份以内)加入PVC后,有助于提高共混物的拉伸强度、弯曲强度;当环氧树脂E51为2份、固化时间为8h时,共混物维卡软化温度达到最大值100.2℃,比纯PVC高出16.5℃。 相似文献
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PVC/环氧树脂E51合金性能的研究 总被引:2,自引:0,他引:2
采用模压法制备了PVC/环氧树脂E51合金,研究了环氧树脂E51用量对合金力学性能及维卡软化温度的影响.结果表明:当环氧树脂E51用量为1~5份时,随着环氧树脂E51用量的增加,试样的缺口冲击强度、拉伸强度、断裂伸长率、维卡软化温度先增加后减小.当环氧树脂E51用量为3份时,试样的缺口冲击强度、拉伸强度、维卡软化温度出现最大值;当环氧树脂E51用量为4份时,试样的断裂伸长率出现最大值;当环氧树脂E51用量为5份时,试样的缺口冲击强度、拉伸强度、维卡软化温度虽有所降低,但仍比原始PVC试样(指未添加环氧树脂E51的试样)高,而试样的断裂伸长率则骤降,比原始PVC试样还低.在试验条件下,环氧树脂E51的最佳用量为3份.试样冲击断面SEM照片的分析结果与缺口冲击强度的测试结果相符. 相似文献
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通过接枝共聚工艺,对纳米水滑石进行表面处理,生成无机核、有机壳的核-壳结构,研究了经表面处理和未经表面处理的水滑石对PVC复合材料力学性能、耐热性能、阻燃性能的影响。结果表明,经表面处理后的水滑石对复合材料力学性能的影响要好于未改性的水滑石;未经处理的水滑石对复合材料维卡软化温度有较大的提高;加入水滑石后,复合材料阻燃性能得到较大提高。 相似文献
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《Ceramics International》2022,48(2):1532-1541
In order to improve the degree of matrix densification of SiCf/SiC composites based on liquid silicon infiltration (LSI) process, the microstructure and mechanical properties of composites according to various pyrolysis temperatures and melt infiltration temperatures were investigated.Comparing the microstructures of SiCf/C carbon preform by a one-step pyrolysis process at 600 °C and two-step pyrolysis process at 600 and 1600 °C, the width of the crack and microcrack formation between the fibers and matrix in the fiber bundle increased during the two-step pyrolysis process. For each pyrolysis process, the density, porosity, and flexural strength of the SiCf/SiC composites manufactured by the LSI process at 1450–1550 °C were measured to evaluate the degree of matrix densification and mechanical properties. As a result, the SiCf/SiC composite that was fabricated by the two-step pyrolysis process and LSI process showed an 18% increase in density, 16%p decrease in porosity, and 150% increase in flexural strength on average compared to the composite fabricated by the one-step pyrolysis process.In addition, among the SiCf/SiC specimens fabricated by the LSI process after the same two-step pyrolysis process, the specimen that underwent the LSI process at 1500 °C showed 30% higher flexural strength on average than those at 1450 or 1550 °C. Furthermore, under the same pyrolysis temperature, the mechanical strength of SiCf/SiC specimens in which the LSI process was performed at 1500 °C was higher than that of the 1550 °C although both porosity and density were almost similar. This is because the mechanical properties of the Tyranno-S grade SiC fibers degraded rapidly with increasing LSI process temperature. 相似文献
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改性空心玻璃微珠/环氧树脂复合材料力学性能研究 总被引:3,自引:2,他引:3
采用偶联剂对玻璃微珠表面进行改性处理,借助超声波振动,使改性空心玻璃微珠在环氧树脂中均匀、稳定分散,增强了玻璃微珠与环氧树脂之间的相容并探讨了改性空心玻璃微珠对环氧树脂力学性能的影响。结果表明,复合材料中改性空心玻璃微珠添加质量分数为3%时,其拉伸强度达到最大值68.54 MPa,与空白样相比提高了20.3%;冲击强度达到最大值24.42 kJ/m2,比纯环氧树脂提高了166%;KIC(断裂韧性)达到最大值2.338 MPa/m2,是空白试样的2.27倍,增韧效果较为明显。 相似文献
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《Ceramics International》2022,48(22):32712-32722
Nano-infiltration and transient eutectic phase (NITE) SiC matrix composites are designed for application in aerospace propulsion systems, particularly in fasteners and thrusters. A variety of carbon fibers with different properties have been selected as reinforcements for SiC matrix composites. Carbon fibers are known to be stable at high temperatures; however, the effects of high applied pressure at high temperatures on the fiber microstructure evolution and mechanical properties are not well-known. As a scoping study for fabricating NITE C/SiC composites, the behaviors of various carbon fibers in SiC composites. Pitch-based fibers, namely, GRANOX XN-05 and YS-90A, and a polyacrylonitrile-based fiber, namely, TORAYCA T-300B, were selected for matrix reinforcement. The 3-point bending test results indicated pseudo-ductile behaviors in the cases of YS-90A and T-300B fiber reinforcements. Fracture resistance evaluation based on the single-notch bending test indicated that the YS-90A fiber reinforced composite afforded the highest fracture resistance among the three C/SiC composites. The microstructure evolution on YS-90A and T-300B fibers was limited to near the fiber surface. Therefore, YS-90A and T-300B carbon fibers are potential candidates for reinforcement in NITE C/SiC composites. 相似文献
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The effect of interfiber distance on the interfacial properties in two dimensional multi‐E‐glass fiber/epoxy resin composites has been investigated using fragmentation test. In addition, the effect of the fiber surface treatment on the interfacial properties has been studied. We found that the interfacial shear strength decreased with the decreasing interfiber distance at the range of <50 μm and the extent of the decreasing was more serious as the increasing of the number of adjacent fiber. This is probably that the interface between the fiber and the resin was damaged by the breaking of adjacent fibers and the damage increased with minimizing the interfiber spacing and the number of adjacent fibers. We can guess that interfacial shear strength in real composites is much smaller than that of multifiber fragmentation sample with touched fiber. When the interfiber distance was >50 μm, the interfacial shear strengths were saturated regardless of fiber surface treatment and were in close agreement with those of the single fiber fragmentation test. Finally, the interfacial shear strength evaluated using two dimensional fragmentation tests are shown as real values in‐site regardless of fiber surface treatment, interfiber distance, and existing matrix cracks. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1541–1551, 2006 相似文献