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以聚乙烯醇(PVA)作为分散剂,聚脲甲醛(PUF)为囊壁,乙烯基硅油为囊芯,成功制备出具有自修复功能且粒径均匀的新型PUF包覆乙烯基硅油微胶囊.实验研究了PVA浓度和搅拌速度对微胶囊的表面形貌及浓度和粒径分布的影响.分别采用傅里叶变换红外光谱、偏光显微镜对微胶囊的结构和形貌进行表征,采用激光粒度仪及同步热分析仪测定微胶囊的粒径大小及分布、热稳定性.结果表明:当PVA浓度为2%,搅拌速率为1 600r/min时,微胶囊粒径均匀,产率可高达90%;在240℃下,微胶囊的热稳定性良好. 相似文献
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研究中采用了正十八烷石蜡相变材料(PCM)芯材,密胺树脂作为囊壁材料,用原位聚合法制备成微胶囊材料。通过改变芯材和囊壁材料的质量比,探讨了微胶囊制备过程中O/W乳化液的相稳定性,并采用SEM,FT-IR,粒度分析仪和DSC对微胶囊的形态及性能进行表征。结果表明芯材增大O/W乳化液的相稳定性下降,微胶囊数量平均粒径和体积平均粒径均减小,当芯材和囊壁材料的质量比(Core/Shell)为1.5∶1时,微胶囊表面光滑致密,平均粒径为3.6μm,相变焓为98.6 MJ/mg。 相似文献
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以聚砜为壁材,桐油为芯材,采用溶剂挥发法制备了聚砜(PSF)包覆桐油自修复微胶囊。考查了不同种类的分散剂、搅拌速度、芯壁比(芯材与壁材的质量比)等工艺参数对微胶囊性能的影响,通过扫描电子显微镜、光学显微镜和热重分析仪等对微胶囊的表观形貌、粒径、壁厚、包覆率和热稳定性能等进行表征。采用所合成的微胶囊制备了环氧树脂基防腐蚀涂层,并对其防腐蚀性能进行了评价。结果表明,30 ℃时,以明胶/聚乙烯醇复配体系作为分散剂,芯材与壁材质量比为1.3:1,搅拌速度为700 r/min时制备出的微胶囊表面光滑致密,粒径在130 μm左右,热稳定温度为350 ℃;盐雾实验结果表明,所制备的微胶囊自修复涂层具有良好的防腐蚀性能。 相似文献
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采用三聚氰胺-脲醛树脂(MUF)为壁材、合成的花椒籽油醇酸树脂为芯材,原位聚合法制备自修复微胶囊,探讨了微胶囊的制备工艺。并采用扫描电子显微镜(SEM)、红外光谱仪(FTIR)、热重分析仪(TGA)和粒径分析仪对微胶囊的表面形貌、化学结构、热稳定性及其粒径分布进行了测试表征。将醇酸树脂微胶囊分散到环氧基体中,研究了环氧涂层的力学性能和自修复性能。实验结果表明,当乳化剂浓度为2.0g/L、芯壁比为2∶1、终点pH为3.5时,微胶囊呈球形结构,无明显的缺陷和损伤,平均粒径为97.44μm,热稳定性良好。当添加质量分数5%的微胶囊时,与未添加微胶囊的自修复涂层相比,其弯曲强度、拉伸强度、黏结强度及其冲击强度分别提高了50.4%、50.0%、40.0%及25.2%,且涂层的自修复性能良好。 相似文献
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采用溶剂蒸发法制备了聚砜包覆双酚A型环氧树脂微胶囊,通过光学显微镜、激光粒度分布仪和微机差热天平对微胶囊的形貌、粒径分布及热性能进行了表征,讨论了分散剂种类及用量、搅拌速度、反应温度以及壁材与芯材投料质量比对微胶囊制备的影响。结果表明,反应温度过高时不能形成微胶囊;选择1.0 %(质量分数,下同)的聚乙烯醇分散剂、搅拌速度为750 r/min、反应温度为30 ℃、壁材与芯材投料质量比为2∶1时制得的微胶囊呈规则球形,产率较高,微胶囊分散较好,平均粒径在100 μm之内。 相似文献
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Preparation and characterization of poly(urea-formaldehyde) microcapsules filled with epoxy resins 总被引:5,自引:0,他引:5
The preparation of microcapsules applied to the fabrication of self-healing composites has been paid more attentions. A new series of microcapsules were prepared by in situ polymerization technology with poly(urea-formaldehyde) (PUF) as a shell material and a mixture of epoxy resins (diglycidyl ether of bisphenol A: DGEBPA) and 1-butyl glycidyl ether (BGE) as core materials. The microencapsulating process of core material was monitored using optical microscopy (OM). The chemical structure of microcapsule was characterized using Fourier-transform infrared spectroscopy (FTIR). Morphology and shell wall thickness of microcapsule were observed using metalloscope (MS), scanning electron microscopy (SEM) and OM, respectively. The effects of different pre-polymers, weight ratios of urea to formaldehyde (U-F) and the agitation rates on the physical properties of microcapsules were investigated. The storage stability of microcapsules at different times and temperatures was analyzed. The thermal properties of microcapsules were investigated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results indicate that PUF microcapsules containing epoxy resins can be synthesized successfully, and during the microencapsulation, the epoxide rings in epoxy resins are hardly affected by the surrounding media. The rough outer surface of microcapsule is composed of agglomerated PUF nanoparticles. The size and surface morphology of microcapsule can be controlled by selecting different processing parameters. The microcapsules basically exhibit good storage stability at room temperature, and they are chemically stable before the heating temperature is up to approximately 238 °C. 相似文献
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为解决日化香精易挥发变质的问题,拓宽其应用领域,采用原位聚合法制备了一系列蜜胺树脂(MF)香精微胶囊。以低甲醚化蜜胺(L-MMF)树脂为例,傅立叶变换红外光谱(FT-IR)的结果证实了微胶囊对香精的良好包覆性,热失重〈TGDTG)分析说明微胶囊大幅提高了香精的耐热性能。进一步采用脲、间苯二酚、聚乙烯醇(PVA)、聚乙二醇(PEG)、氯化钠对蜜胺树脂进行改性并与未改性的树脂及不同甲醚化程度的蜜胺树脂进行对比,研究了改性对微胶囊包覆效果的影响。结果表明,低甲醚化蜜胺树脂和聚乙烯醇改性蜜胺树脂对香精的包覆效果较好,所得香精微胶囊粒径小,分布窄,包覆率高。 相似文献
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以合成硫磺为芯材,聚苯乙烯为壳材,采用原位接枝改性聚合方法制备了聚苯乙烯接枝包覆硫磺微胶囊,研究了不同苯乙烯/硫磺颗粒配比对微胶囊形貌的影响,制备了粒径均一分布的硫磺微胶囊,且分散均匀。结果表明苯乙烯的含量对微胶囊的表面形貌有很大影响,经包覆之后硫磺微胶囊的热稳定性提高。 相似文献
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Microcapsule with poly(ethylene‐co‐vinylacetate) (EVA) core‐polyurethane (PU) shell structure was synthesized by interfacial polymerization in aqueous polyol dispersion with ethylene diamine as the chain extender of toluene diisocyanate in poly(vinyl alcohol) aqueous solution as the stabilizing agent. The effects of polyol constituent on the average particle size and distributions, morphologies, color strength, and friction fastness of core‐shell particles were investigated to design microcapsule. The friction fastness of printed fabrics with EVA core‐PU shell microcapsules became the increase to 4–5 grades. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 893–902, 2007 相似文献
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Based on the deficiency of traditional acidification or acid pressure technology in the development of carbonate oil and gas resources, a microcapsule which wraps hydrochloric acid and can be released through temperature control was prepared by using microcapsule technology. The microcapsules were prepared with polyurethane prepolymer (PUA) and 1,6-hexadiol diacrylate (HDDA) polymer as wall material and hydrochloric acid as core material by two emulsification and photocatalysis methods. Its parcel rate is 61.9%. Fourier transform infrared spectroscopy characterization confirmed the successful photopolymerization of PUA prepolymer and HDDA in a strong acid environment. The microscopic morphology analysis of electron microscope showed that the microcapsule was regular and uniform spherical with smooth and dense surface. The particle size analysis showed that the microcapsules were mainly distributed between 40 and 300 μm, and the average particle size was 114.02 μm.The glass temperature of microcapsule wall material was 97°C by DSC method. The release rate of microcapsules was accelerated with the increase of release temperature. The cumulative release rate of acid solution of microcapsules for 3 h reached 28.4%, and the final release rate of microcapsules for 12 h reached 90.7% under 100°C. In addition, the release of microcapsules is less affected by the formation salinity. At 90°C, the maximum release rate of 7.5 g/L CaCL2 was 49.1%, lower than that of 59.4% in pure water, showing the good salt resistance of the wall materials of microcapsules. 相似文献