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采用原位聚合法,以脲醛树脂和密胺树脂预聚体为壳材、双环戊二烯(DCPD)为芯材,制备了两种DCPD微胶囊。通过扫描电子显微镜、傅里叶变换红外光谱((FTIR)对微胶囊进行了表征,并将其添加到环氧树脂(EP)中测试复合材料的力学性能。结果表明,脲醛树脂包覆DCPD微胶囊呈球形,粒径为40~80μm,壁厚为1~2μm;密胺树脂包覆DCPD微胶囊颗粒分布不规则,粒径为15~20μm,壁厚为2~5μm。两种微胶囊的FTIR谱图除了具有壳材料脲醛树脂和密胺树脂的特征峰外,在1 251,3 051 cm-1处均有芯材DCPD的特征峰,证明DCPD芯材已被两种壳材料成功包覆。随着微胶囊用量的增加,EP/微胶囊复合材料的拉伸强度和冲击强度均呈先增大后减小的趋势,拉伸强度和冲击强度分别在微胶囊质量分数分别为15%和10%时达到最大值,在相同条件下,加入密胺树脂包覆DCPD的复合材料的力学性能明显好于加入脲醛树脂包覆DCPD微胶囊的复合材料。 相似文献
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共轭亚油酸粉末化微胶囊的制备 总被引:1,自引:0,他引:1
研究了喷雾干燥法制备共轭亚油酸微胶囊的工艺参数及配比条件。结果表明,最佳的工艺参数及配比条件为:乳液80℃热处理60 m in,乳化剂蔗糖酯加入量为水液的1%~1.5%,大豆分离蛋白与麦芽糊精质量比为1∶4,壁材中玉米糖浆含量38.5%,固形物含量16.7%,共轭亚油酸理论含量16%左右,进风温度130~150℃,进料流量(2.5~3.5)×150 mL/h,进料温度35℃,进风流量1.1 m3/m in左右,喷嘴压力180 kPa。制备出的共轭亚油酸微胶囊有较好的产品质量。 相似文献
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《精细化工》2017,(9)
以季铵化壳聚糖(QCTS)为壁材、腐殖酸(HA)为芯材,制备了季铵化壳聚糖包覆腐殖酸(QCTS/HA)微胶囊。采用傅里叶变换红外光谱(FTIR)、偏光显微镜(POM)、扫描电子显微镜(SEM)对微胶囊的性能进行了表征。以芯壁比[m(HA)∶m(QCTS)]、固化剂硫酸钠的用量和搅拌速度作为单因素,探讨了微胶囊的最佳制备条件。并且对最佳制备条件下的微胶囊进行了形貌观测以及吸水性和保水性测试。结果表明,QCTS/HA微胶囊的最佳制备条件为:m(HA)∶m(QCTS)=3∶1,硫酸钠用量为QCTS/HA总质量的1.0%,搅拌速度为500 r/min;与相同制备条件得到的未改性微胶囊CTS/HA相比,改性后的QCTS/HA微胶囊包覆层表面孔隙结构比较完善,分布均匀,孔洞较多,具有更加优异的吸水性和保水性,其12 h的吸水率和保水率分别高达348%和208%。 相似文献
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以季铵化壳聚糖(QCTS)为壁材、腐殖酸(HA)为芯材,制备季铵化壳聚糖包覆腐殖酸(QCTS/HA)微胶囊。采用傅里叶红外光谱(FTIR)、偏光显微镜(POM)、扫描电子显微镜(SEM)对微胶囊的性能进行表征。以芯壁比〔m(HA):m(QCTS)〕、固化剂用量和搅拌速度作为单因素,探讨了微胶囊的最佳制备条件。并且对最佳制备条件下的微胶囊进行了形貌观测以及吸水和保水性能测试。结果表明,QCTS/HA微胶囊的最佳工艺参数为:m(HA):m(QCTS)=3:1,固化剂用量为总质量的1%,搅拌速度为500r/min;与相同条件下未改性的微胶囊CTS/HA相比,改性后的QCTS/HA微胶囊包覆层表面孔隙结构比较完善,分布均匀,孔洞较多,具有更加优异的吸水和保水性能,其12h的吸水率和保水率分别高达348%和208%。
关键词:季铵化壳聚糖;腐殖酸;核壳结构;微胶囊;吸水性能,保水性能 相似文献
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Double‐shell microcapsules containing butyl stearate were prepared through interfacial polymerization. The outer shell is polyurea formed through polymerization of toluene‐2,4‐diisocyanate (TDI) and diethylene triamine, and the inner shell is polyurethane (PU) formed through polymerization of TDI and polypropylene glycol 2000 (PPG2000). Styrene maleic anhydride copolymer was used as emulsifier. The effects of core to monomer ratio and dosage of PPG2000 on core content and encapsulation efficiency of microcapsules were investigated. The core content has a maximum at core to monomer ratio of 3–4, and the encapsulation efficiency has a maximum value of 95% at core to monomer ratio of 2. The prepared microcapsules were smooth and compact and have an obvious latent heat of 85 J/g. The shell structure of microcapsules was polyurea and PU. The average diameter of the microcapsules was 1–5 μm. The stabilities of the double‐shell microcapsule, such as anti‐ethanol wash and antiheat properties are obviously improved than those of single‐shell microcapsule. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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The microcapsules with cores of ethylenediamine tetraacetic acid tetrasodium salt (Na4-EDTA) and walls of polyurea were synthesized via an interfacial polycondensation reaction with 2,4-tolylene diisocyanate as an oil-soluble monomer and diethyl triamine as a water-soluble monomer. Various manufacturing parameters, including the amount of emulsifier, agitation speed, stirring time and ratios of the wall materials to core materials, were altered to optimize process variables during the synthesis of microcap-sules, and the effects of these parameters on the characteristics of the microcapsules were examined. The structure, morphology, mean particle size and size distribution were characterized by optical microscope and scanning electron microscopy (SEM), showing that the mean diameter of optimal microspheres was approximately 6 μm, and microcapsules were spherical. In vitro release of Na4-EDTA from these microcapsules was performed in distilled water. Under the optimal preparation conditions, the Na4-EDTA re-lease profiles were biphasic with a burst release followed by a gradual release phase. After an initial burst, a continuous Na4-EDTA release was up to 5-7 days. The optimal synthesis conditions for the microcapsules with stable, good morphology and good con-trolled-release properties were as follows: emulsifier Span-80 10% (by mass), agitation speed 900 r&;#8226;min-1, stirring time 30 min, and the ratio of the wall materials to core materials 0.15. 相似文献
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We synthesized core-shell microcapsule absorbents with cPAA (cross-linked poly(acrylic acid)) as the core and PSMA (poly(styrene-alt-maleic anhydride)) as the shell by precipitation polymerization, where the shell served to delay the absorption of excess water in cement mortars. To control shell thickness, the cPAA-PSMA capsules were synthesized with core monomer mass to shell monomer mass ratios of 1/0.5, 1/1, and 1/1.5. We observed the hydrolysis of the PSMA polymer in a cement-saturated aqueous solution by Fourier transform infrared (FT-IR) spectroscopy. Furthermore, core-shell structures were observed for 1/1 (cPAA-PSMA #3) and 1/1.5 (cPAA-PSMA #4) core/shell monomer mass ratios, whereas no core-shell structures were observed for the 1/0.5 (cPAA-PSMA #2) microcapsules by transmission electron microscopy (TEM). 相似文献
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Effects of shell crosslinking on polyurea microcapsules containing a free‐radical initiator
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Microencapsulation of a material is often used when a controlled release of a substance is desired. This study examines the effects of crosslinking in polyurea microcapsule shells on stability of microcapsules containing the free‐radical initiator cumene hydroperoxide (CHP). Crosslinking of polyurea shells was varied by using amine monomers containing different amine functionalities, and/or changing the isocyanate/primary amine ratio. Thermogravimetric analysis was performed to determine thermal properties of these microcapsules, and the pot lives of monomer systems containing these microcapsules were measured. Thermal stability is greater with a moderate degree of crosslinking from a trifunctional amine, and decreases when crosslinking is increased through use of higher amine functionality. Stability in monomer media generally increases with increased crosslinking through higher amine functionality, but is less predictable due to crosslinks formed between capsules. Generally, increasing crosslinking through altering the isocyanate to primary amine ratio decreases capsule stability in both dry and monomer storage. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42408. 相似文献
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主要考察负载雷帕霉素(Rapaymcin,RAPA)的壳聚糖(Chitosan,CS)微球在加入左旋聚乳酸(L—polylactic acid,PLLA)时的载药量,包封率及在不同溶剂中的缓释性能。采用三聚磷酸钠(Sodium tripolyphosphate,TPP)作为离子交联剂,应用离子凝聚法制备CS/PLLA/TPP纳米微胶囊,用透射电镜和粒径分析仪进行了表征。结果表明:离子凝胶法可以得到粒径约300—400nm均匀分散的壳聚糖纳米微胶囊;微胶囊包封率可达84.25%,微胶囊载药量可达30.22%,雷帕霉素在不同溶剂中的缓释性能有很大不同。 相似文献
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《塑料、橡胶和复合材料》2013,42(9):279-283
AbstractThe addition of self-healing properties to polystyrene block–polyisoprene block–polystyrene by loading the polymeric matrix with microcapsules filled with monomer [dicyclopentadiene (DCPD)] and first generation Grubbs catalyst is described in detail. The confinement of DCPD in polyurea formaldehyde microcapsules has been demonstrated by Raman spectroscopy. The above mentioned components (polymeric matrix, microcapsules filled with monomer and catalyst) have been mixed in solution, and the solvent has been slowly evaporated. The polymerisation of the monomer (DCPD) within the self-healed polymeric system after the fracture of microcapsules has been confirmed by Raman spectroscopy. Slow stress–strain mechanical testing has confirmed the efficiency of the added self-healing capabilities. 相似文献
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Preparation of polymeric microcapsules enclosing microbial cells by radical suspension polymerization via water-in-oil-in-water emulsion 总被引:1,自引:0,他引:1
Takayuki Takei Kaoru Ikeda Hiroyuki Ijima Koei Kawakami Masahiro Yoshida Yasuo Hatate 《Polymer Bulletin》2010,65(3):283-291
Polymeric microcapsules enclosing Saccharomyces cerevisiae were prepared by radical suspension polymerization via water-in-oil-in-water emulsion. Trimethylolpropane trimethacrylate
and 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile) were used as monomer and radical initiator, respectively. A culture medium
with suspended yeast cells, monomer solution with the dissolved radical initiator, and poly(vinyl alcohol) aqueous solution
were used as inner aqueous phase, oil phase, and outer aqueous phase, respectively. The influence of microcapsule preparation
parameters on the viability of encapsulated cells and encapsulation efficiency was investigated. The radical polymerization
process did not cause significant damage to encapsulated yeast cells. Decreased weight ratio of aqueous phase to oil phase
resulted in increased encapsulation efficiency of the cells. The diameter of the microcapsules could be controlled by varying
the agitation rate. 相似文献
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Photosensitive microcapsules, which are thermally quite stable, are formed via interfacial polycondensation in which one of the shell-forming reactants contains an azo function. An azo monomer, containing α,ω-carboxylic diacid dichloride was reacted with a trifunctional aliphatic amine on the oil-water interface resulting in a shell-forming crosslinked polyamide. The size of the resulting photosensitive microcapsules was determined. It could be shown that these microcapsules can be opened by means of UV-light. 相似文献
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Tsutomu Matsui Masahiro Yoshida Yasuo Hatate 《Chemical Engineering Communications》2007,194(2):248-259
Nylon-polystyrene microcapsules with immobilized ferroelectric liquid crystalline segments were prepared, and the permeability control of the encapsulated core material was investigated under an external electric field. A ferroelectric liquid crystal monomer possessing both mesogenicity and chirality effectively responded to an external electrical field. Permeation of the material (oxprenolol) contained in the inner aqueous core of the microcapsules was enhanced under a feeble electric field (2 V). Furthermore, it was found that the permeability of the microcapsules without the ferroelectric liquid crystal group did not depend on the external electrical field. In order to clarify the controlled release mechanism of the core material, the transmittance was quantitatively evaluated under an external electric field using a handmade polarized light transmittance apparatus. 相似文献