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纳米SiO_2对聚丙烯/环氧树脂共混物性能的影响 总被引:1,自引:1,他引:0
采用熔融共混法制备了聚丙烯(PP)/环氧树脂(EP)共混物,研究了纳米SiO2对共混物性能的影响。结果表明:与纯PP相比,PP/EP共混物的冲击强度、断裂伸长率及黏度降低,弯曲模量增大;在PP/EP共混物中加入纳米SiO2后,共混物弯曲模量和冲击强度明显提高;将硅烷偶联剂KH550改性的纳米SiO2(SiO2-KH550)添加到共混物中,在EP为17%、SiO2-KH550为7%时,共混物的弯曲模量比纯PP提高了64%;EP降低了PP的结晶温度。 相似文献
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环氧树脂/氰酸酯树脂体系的改性研究 总被引:1,自引:0,他引:1
为增加环氧树脂/氰酸酯树脂体系(EP/CE)的韧性,向EP/CE树脂体系中引入第三组分——双酚A(BPA)。采用傅里叶转换红外光谱、差式扫描量热仪研究了BPA对EP/CE固化温度与固化机理的影响,测定了固化物的力学性能和耐湿热性。结果表明,BPA的加入改变了EP/CE树脂体系固化历程,引起EP/CE树脂体系固化温度明显下降。BPA在EP/CE树脂体系内可形成大量的—C—O—C—键,与EP/CE树脂体系形成互穿网络,提高了EP/CE的韧性。随着体系中BPA含量的增加,其力学性能提高,吸水率有所下降。当CE∶EP∶BPA质量比为7∶3∶0.75时,其拉伸强度提高27.3%,冲击强度提高34.7%,吸湿率降为1.2%。 相似文献
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环氧树脂对PVC/ABS共混物性能的影响 总被引:2,自引:0,他引:2
研究了固体环氧树脂(EP)对聚氯乙烯(PVC)/丙烯腈-丁二烯-苯乙烯共聚物(ABS)/EP共混物力学性能和热稳定性的影响,重点考察了EP环氧值和固化剂DDM对共混物性能的影响。结果表明:PVC/ABS/EP共混物表现为脆性断裂;加入DDM后,共混物的拉伸强度明显提高,但冲击性能影响不大;对于PVC/ABS/EP/DDM共混物,随着EP含量的增加,共混物的拉伸强度上升,且环氧值高的EP704对共混物拉伸强度的提高更大;加入2%的低环氧值EP903后,共混物的冲击强度达到最大值,而EP704的加入则对共混物的冲击性能影响不大;环氧树脂的加入在一定程度上削弱了PVC/ABS共混物的热稳定性。 相似文献
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《合成纤维》2016,(2):13-18
利用环氧树脂(EP)与聚对苯二甲酸丁二醇酯(PBT)的相容性,考察了EP对共混物PBT/ABS-gGMA性能的影响。采用动态力学分析仪(DMA)、旋转流变仪、Haake流变仪和扫描电镜(SEM)研究共混物的性能。DMA、DSC和旋转流变仪的测试结果表明PBT与EP是相容的;流变性能测试结果表明EP对PBT/ABS-g-GMA共混体系起到增容作用;SEM观察结果发现少量的EP加入对共混物的相形态没有明显影响,分散相在PBT基体中均匀、稳定分散,而过量的EP使共混物中出现一些较大的相区,分散相发生团聚;力学性能测试结果表明适量的EP就能明显提高共混物的冲击性能,而过量的EP又会使共混物的冲击强度下降。 相似文献
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《Ceramics International》2020,46(9):13695-13703
Manganese–copper ferrite (MCFO) and dysprosium (Dy)-doped manganese–copper ferrite nanocomposites (Mn0.5Cu0.5DyxFe2−xO4) (x = 0, 0.05, 0.10, and 0.15) were synthesized by sonochemical method. Crystal structure and the structural parameters of the MCFO were analyzed based on the doping concentration of Dy ion. It was observed that the average crystalline size of the synthesized nanocomposite decreases when the concentration of Dy increases. The existing spherical surface morphology of the MCFO and Dy-doped MCFO nanocomposites were obtained through scanning electron microscopy. In the UV spectrum, the pristine MCFO sample showed an absorbance peak at 743 nm whereas the absorbance values of Dy-doped ferrite nanocomposite considerably shifted (blue) toward a lower wavelength (231–222 nm). The dielectric parameters of all ferrite nanocomposites were studied in the frequency range of 100 Hz to 5 MHz. The dielectric spectrum revealed that dielectric constant and loss tangent decreased with increased doping concentration of Dy ion. The saturation magnetization also changed with Dy doping in MCFO. The impact of Dy on manganese–copper ferrite changed the optical, dielectric and magnetic properties of the prepared binary ferrite nanocomposite, which can be used for microwave-absorbing material applications. 相似文献
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E. S. Zainudin S. M. Sapuan K. Abdan M. T. M. Mohamad 《Polymer-Plastics Technology and Engineering》2013,52(1):97-101
Mechanical strengths of a banana pseudo-stem (BPS) fiber and unplasticized polyvinyl chloride (UPVC) composite were evaluated to assess the possibility of using it as a new material in engineering applications. Samples were fabricated by the compression molding process with reference to the effect of filler loading. The samples were submitted to mechanical tests to measure tensile, flexural, and impact properties of the composites. The nature of adhesion between the matrix and the reinforcement and information relating the structure of mechanical properties can be obtained by scanning electron microscopy (SEM) assessment of the composite fracture surface. The mechanical properties show that the composites did not have good adhesion between filler and matrix; on the other hand, the filler insertion improved the flexural modulus and the material rigidity. 相似文献
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核壳纳米粒子作为复合纳米粒子一个重要的分支,由于其光、磁和催化等方面的优异性能,近年来引起了人们广泛的关注.本文主要介绍了核壳纳米粒子的制备方法及诸多性能,并对核壳纳米粒子的发展进行了展望. 相似文献
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王丽 《合成材料老化与应用》2014,(4):15-17
分别以聚四氢呋喃醚二醇(PTMEG)、聚氧化丙烯二醇(PPG-1000)为软段,以二苯基甲烷二异氰酸酯(MDI-50、MDI-100LL),以及扩链剂1,4-丁二醇(BDO)、三羟甲基丙烷(TMP)为硬段,采用预聚体法制备了聚氨酯弹性体。并系统研究了聚氨酯体系中各组分的种类对材料机械性能和阻尼性能的影响。 相似文献
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《Ceramics International》2020,46(2):1974-1981
Nowadays, complicated preparation processes and harsh sintering conditions wave transparent ceramics limit its further development. To solve this problem, we explore a promising precursor by adopting a polymerization-pyrolysis method to prepare porous Si–Al–O–B ceramics at a mild sintering condition (1000 °C). The porous Si–Al–O–B ceramics exhibits enhanced wave transparency at 10–16 GHz with a low dielectric constant (<3), a low loss angle tangent value (<0.01), and simultaneously, a relative high flexible strength of 82 MPa. According to the results of the XRD and FTIR analysis, porous Al4B2O9 crystallization dispersed in the amorphous SiO2 matrix constructs the main phases of the products. The changes of Al and B elements are confirmed to have an effect on the phase compositions and micro structure of the composite ceramics, which obviously affect the mechanical and dielectric properties of the derived ceramics. The as-prepared porous Si–Al–O–B ceramics could be a potential candidate for next generation electronic window materials due to its low dielectric constant and loss angle tangent value, as well as high flexible strength. 相似文献
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Effects of support and additive on oxidation state and activity of Pt catalyst in propane combustion 总被引:1,自引:0,他引:1
The effects of support and additive on the oxidation state and catalytic activity of Pt catalyst in the low temperature propane combustion were systematically investigated on Pt/MgO, Pt/Al2O3 and Pt/SiO2–Al2O3. The catalytic activity varied much with both support materials and additives. The catalyst on the more acidic support showed higher activity, and the catalytic activity on every support materials increased as the electronegativity of additives increased, while some additives decreased the activity. The oxidation state of platinum, estimated by white line intensity of Pt LIII-edge XANES spectrum, also varied with the support and additives, and additives with higher electronegativity greatly prevented the platinum from its oxidation under oxidising atmosphere. Among almost all the catalysts with various supports and various additives, a clear relationship was observed between the oxidation state of platinum and the catalytic activity; the more metallic platinum showed higher activity. Thus, it was concluded that the total electrophilic/electrophobic property derived from those of the support and additive controls the oxidation state of platinum, which intensively affects the catalytic activity; i.e. higher electrophilic property provides less oxidised platinum, resulting in high catalytic activity. The mechanism of this effect was also discussed on the basis of thermochemical data, and it was proposed that the electrophobic materials promote the noble metal oxidation since the noble metal oxo-anion such as PtOδ− is more stabilised with electrophobic cation. 相似文献