共查询到20条相似文献,搜索用时 109 毫秒
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采用预乳化饥饿型滴加方法结合碱溶胀处理制备了聚(甲基丙烯酸-甲基丙烯酸甲酯-丙烯酸正丁酯)/聚(甲基丙烯酸甲酯-苯乙烯-甲基丙烯酸)中空聚合物微球。试验集中讨论了种子阶段粒子大小,种子阶段引发剂用量、扩径时不同核壳比及不同碱进行碱处理时对形成中空聚合物微球的影响。同时采用TEM观察聚合物微球结构。试验所得的聚合物微球外径约为400 nm,内径约为220 nm。 相似文献
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采用乳液聚合协同碱渗透溶胀法,制备了亚微米中空微球聚合物。通过SEM、TEM、DLS分别对中空微球的形貌和粒径进行表征,并考察了中空微球聚合物的遮盖性能。研究了引发剂用量对核粒径的影响,中间层和壳层聚合物配比对微球形貌结构及其遮盖性能的影响。结果表明,在核制备过程中,核的粒径随引发剂用量的增加而减小;对于平均粒径为148 nm的核,当中间层甲基丙烯酸丁酯(BMA)用量为10 wt%、甲基丙烯酸(MAA)用量为3 wt%,甲基丙烯酸甲酯(MMA)用量为87 wt%,壳层苯乙烯(St)用量为97 wt%,交联剂用量为3 wt%时,可制备平均粒径414 nm,中空率为40.6 %的聚合物微球,且微球表面较为光滑,此时中空微球聚合物具有优异遮盖性能,遮盖度达到66 %。 相似文献
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BACKGROUND: Phenolic hollow microspheres with a closed structure have a set of outstanding thermal characteristics. In the work reported here, a facile method is introduced to fabricate phenolic closed hollow microspheres by in situ polymerization in oil‐in‐water emulsion. Although in situ polymerization has been widely used to prepare hollow microspheres, it has not been utilized for the preparation of phenolic hollow microspheres. RESULTS: The average particle size of the produced microspheres was about 500 µm. Fourier transform infrared spectroscopy indicated that the phenolic microspheres were partially cured during preparation and a significant number of hydroxymethyl groups remained in the microspheres. Thermogravimetric analysis showed that the thermal decomposition temperature of the phenolic hollow microspheres was 420 °C, and residual weight at 800 °C was 62%. Differential thermal analysis showed that the glass transition temperature of the phenolic hollow microspheres was 200 °C. CONCLUSION: Using in situ polymerization, high thermal performance phenolic hollow microspheres are produced. The resultant product possesses a satisfactory closed hollow structure with controlled morphology. Copyright © 2009 Society of Chemical Industry 相似文献
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采用苯乙烯–马来酸酐共聚物中空微球对尼龙6的轻量化改性进行了研究。采用傅立叶变换红外光谱仪对苯乙烯–马来酸酐共聚物中空微球进行了表征,采用差示扫描量热仪和热失重分析仪对苯乙烯–马来酸酐共聚物中空微球进行了热分析。将苯乙烯–马来酸酐共聚物中空微球以不同比例与尼龙6熔融共混制备轻量化共混料,测定其成型样品的减重效果和拉伸性能并采用扫描电子纤维镜表征共混物中中空微球的结构与形态。结果表明,中空微球具有良好的刚性和耐热性,与尼龙6相容性良好。当中空微球添加量为5%时,尼龙6/苯乙烯–马来酸酐共聚物中空微球共混物的实际质量减轻10%,拉伸强度为40 MPa。 相似文献
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以油页岩灰渣为实验原料,利用火焰喷枪熔射法制备了空心陶瓷微球.采用TG-DSC对油页岩灰渣进行热分析,采用SEM和XRD分别对油页岩灰渣和空心陶瓷微球的微观形貌和物相组成进行分析.研究结果表明,利用火焰喷枪熔射法制备的微球绝大多数为球状,极少部分为不规则形状,微球破碎后可发现其为空心结构;空心微球的形成机理为:油页岩灰渣粉末受热熔化、发气物质形成气泡、气泡合并、降温凝固、最终形成空心微球;油页岩灰渣自身疏松的结构、所含充足的发气物质和适宜的熔射温度是形成微球空心结构的重要因素. 相似文献
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沈晓钦 《玻璃钢/复合材料》2018,(4):102-105,50
以混合后的石英纤维、酚醛纤维和酚醛空心微球作为增强体,加入酚醛树脂制备出复合材料。研究了酚醛空心微球不同配比对复合材料各项力学性能、隔热性能、微观形貌的影响。结果表明,酚醛空心微球能降低复合材料的密度,提升隔热性能,降低力学性能。当酚醛空心微球含量为6%时,酚醛空心微球分散均匀,复合材料的隔热性能有明显提升,材料的比拉伸强度和比压缩强度值最大,获得的效益最高。 相似文献
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Porous hollow CeO2 microspheres were fabricated using negative-charged PS microspheres as templates by a facile method. The hollow CeO2 microspheres were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and N2 adsorption?Cdesorption. The results showed that the as-synthesized hollow CeO2 microspheres are well monodisperse and uniform in size. The porous shells of hollow microspheres are relatively rough and composed of tiny nanoparticles. The external diameter, internal diameter, and shell thickness of hollow CeO2 microspheres are about 190, 160, and 15?nm, respectively. A possible mechanism for the formation of hollow CeO2 spheres was also discussed. 相似文献