共查询到19条相似文献,搜索用时 169 毫秒
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大孔高交联苯乙烯—双烯—A共聚物的合成及孔结构的研究 总被引:2,自引:0,他引:2
利用新型闻联剂-双甲基丙烯酰氧苯基丙烷(双烯-A)与苯乙烯悬浮共聚合,以甲苯、异戊醇作致孔剂,合成了一系列大孔高交联共聚物,考察了双烯-A用量、甲苯/异戊醇配比、 引发剂用量及分散剂用量对共聚物孔结构的影响。通过红外光谱、表观密度、全自动物理吸附仪及扫描电镜对干燥的共聚物小球进行了表征。结果表明,随交联剂双烯-A含量的增加,苯乙烯-双烯-A共聚物的表面孔结构明显增大,共聚物的比表面积、孔容及孔径均 相似文献
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N—苯基马来酰亚胺与苯乙烯共聚合的研究 总被引:4,自引:0,他引:4
对N-苯基马来酰亚胺与苯乙烯悬浮聚合体系作了系统的研究,找到适合该体系的最佳反应温度,单体用量化,引发剂用量,搅拌速度以及水油比。通过采用聚乙烯醇,CMC-Na盐,无机粉末混合分散剂,得到稳定的悬浮体系,产物为颗粒起先均匀分布在0.5-0.7mm范围内的IP树脂。 相似文献
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在不同反应温度下对多孔苯乙烯-二乙烯基苯共聚物微球进行磺化亲水性修饰,采用扫描电镜与氮气吸附法,研究多孔微球的孔结构。结果显示,磺化反应修饰后,微球的孔容与比表面积变小,且随着磺化温度升高,比表面积与孔容递减。交换容量则随着磺化温度升高而递增。用牛血清蛋白作为模型蛋白质,研究了亲水性修饰后的多孔苯乙烯-二乙烯基苯共聚物微球对蛋白质大分子吸附性能的影响。实验结果表明,牛血清蛋白在磺化微球上的吸附主要由孔容与比表面积决定,孔容与比表面积越大,蛋白质吸附量也越大。吸附速率表现为疏水作用快于静电作用。吸附动力学研究表明,Kannan-Sundaram模型可较好地描述牛血清蛋白的吸附动力学行为。 相似文献
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以邻氯苯乙烯和二乙烯基苯为原料制备了邻氯苯乙烯-二乙烯基苯强酸性阳离子交换树脂,考察了水油比、分散剂、助分散剂等因素对合成树脂的影响。研究表明,该树脂的合成最佳工艺条件为:水油比3:1~4:1,聚乙烯醇与明胶分别为水相质量的0.1%和1.0%,助分散剂为水相质量的0.5%,电解质为水相质量的10%,在40~80℃的成球关键期控制升温速率为20℃/h,在80~110℃以发烟硫酸辅助磺化,得到交换量大于4mmol/g的树脂,优化了该树脂的合成工艺。 相似文献
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本文以KH560、苯乙烯、马来酸酐为连接组分,将二氧化钛接枝到聚(苯乙烯-二乙烯基苯)微球的表面,成功制备了无孔和多孔纳米复合微球。研究了硅烷偶联剂(KH560)和苯乙烯对二氧化钛在无孔微球表面的分散性和接枝数量以及支撑微球的多孔性质对接枝到微球内部的二氧化钛数量的影响。结果表明,KH560和苯乙烯能够提高二氧化钛在微球表面的分散性和稳定性,使二氧化钛以30-80nm的粒径接枝在微球表面。苯乙烯又能使二氧化钛在无孔微球表面的接枝数量从10.4%增大到20.4%。平均孔径为136nm的多孔微球为支撑微球得到的复合粒子中二氧化钛最高接枝量可达26%,明显高于无孔微球和平均孔径为31nm的多孔微球。 相似文献
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采用悬浮聚合方法合成了多孔交联聚苯乙烯微球,研究发现微球的粒径与分散剂含量、水油比、搅拌速度和成孔剂有关,而微球的孔径与成孔剂的种类和含量有关。 增加分散剂的用量,提高水油比和加快搅拌速度都能导致微球的粒径减小。 微球的孔径和粒径均随着成孔剂与聚合物溶度参数差值变大而增加。通过改变以上条件得到粒径为100~300 μm和孔径为8~36 nm的交联度为27%的多孔交联聚苯乙烯微球,并利用光学显微镜、场发射扫描电子显微镜(SEM)和氮气吸附解吸法对微球进行了相应的表征。 得到的微球在固相合成载体中有一定的应用前景。 相似文献
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合成并表征了含2,6吡啶二羧酸根二茂钛基团的苯乙烯单体.通过含钛单体与苯乙烯的溶液共聚反应得到了稳定性高且可溶的共聚物.所得到的共聚物能溶于THF,CHZCh和甲苯中,其玻璃化转变温度为106℃.该含钛聚苯乙烯有望应用于惯性约束聚变(ICF)实验靶用聚合物微球的制备. 相似文献
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SynthesisofPoly(styrene┐co┐divinylbenzene)┐supportedDichloroCyanuricAcidZHONGJing-fang*,LIChen-xi,HEBing-linandWUZhi-zhong(St... 相似文献
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Macroporous poly(vinyl acetate-co-triallyl isocyanurate)beads were prepared with suspension polymerization method.The copolymer beads were then transformed into poly(vinyl alcohol-co-triallyl isocyanurate)by ester exchange reaction.Aminocarboxylic acids were immobilized on the copolymer beads by the esterification of hydroxyl groups with diethyl-lenetriaminepentaacetic bisanhydride,The weak acid exchange capacities,specific surface areas and mean pore diameters of the rsultant resin beads were measured. 相似文献
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Luciana S. Peixoto Fabricio M. Silva Mariana A. L. Niemeyer Gaudencio Espinosa Príamo A. Melo Márcio Nele José Carlos Pinto 《Macromolecular Symposia》2006,243(1):190-199
Poly(vinyl alcohol), PVA, is the most frequently used material in embolization of tumors, aneurisms and arteriovenous malformations due to its low toxicity, good biocompatibility and desirable physical properties. It is well known that PVA particles cannot be prepared by direct polymerization of vinyl alcohol. Its synthesis is typically performed by the suspension polymerization of vinyl acetate to produce poly(vinyl acetate), PVAc, followed by the saponification of the PVAc particles. This work shows that, using the suspension polymerization technique, it is possible to obtain spherical particles with a core-shell structure of PVA/PVAc with regular morphology, instead of particles with irregular shapes and sizes, as usually found in many commercial embolization products. Therefore, this work presents the production of PVA/PVAc spherical particles that can be used to occlude blood vessels, eliminating the disadvantages of commercial PVA. In vivo clinical tests with white “New Zealand” rabbits undergoing kidney inflammation reaction have shown that these spherical particles are much more efficient for vascular embolization. 相似文献
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A novel biodegradable block copolymer poly(lactic acid-b-lysine) (PLA-b-PLL) has been synthesized and characterized in this study. This product was synthesized via a five-step reaction: Synthesis of hydroxyl-tailed poly(lactic acid) (PLA) by the ring-opening polymerization (ROP) of D,L-lactide in the presence of stannous octoate (Sn(OCt)2) as initiator; coupling N-t-butoxycarbonyl-L-phenylalanine to hydroxyl-tailed PLA using dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP); the amino-tailed PLA was obtained through de-protection of the Boc-protective group in trifluoroacetic acid (TFA) solution; and then ring-opening polymerization of N ε -(Z)-lysine-N-carboxyanhydride (NCA) using the amino-tailed PLA as macro-initiator; finally removal of the Cbz-protective group of PLA-b-poly(N ε -(Z)-L-lysine) (PLA-b-PLL(Z) in a mixed hydrobromic acid/acetic acid solution to give the target copolymer. The characterization of this copolymer and its precursors were performed by 1H-NMR, FTIR and GPC. The block copolymer PLA-b-PLL, combining the characteristics of an aliphatic polyester and poly(amino acids), could be of potential interest in a variety of medical applications, such as the fields of targeted drug delivery and gene delivery systems. 相似文献
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A novel thermo-responsive diblock copolymer of poly(N-vinyl-2-pyrrolidinone)-block-poly(N-isopropylacrylamide) (PNVP-b-PNIPAM) was synthesized. FT-IR, 1H-NMR and SEC results confirmed the successful synthesis of PNVP-b-PNIPAM diblock copolymer via anionic polymerization. The polymeric micelles formed from PNVP-b-PNIPAM copolymer in aqueous solution were developed and characterized as a potential thermo-responsive and biocompatible drug delivery system. Micellization of the diblock copolymer in aqueous solution was characterized by dynamic laser scattering (DLS), turbidity measurement, tension measurement and transmission electron microscopy (TEM). The thermo-responsive polymeric micelles with the size ranges of 200 to 260 nm and thickness of 30 nm are localized, selected and targeted for drug release, having a great potential in response to external-stimulus such as temperatures from 35 to 39°C. The critical micellization concentration (cmc) of PNVP-b-PNIPAM in aqueous solution is 0.0026 wt% determined by turbidity measurement. The size of micelles determined by DLS increased from 163 to 329 nm with increasing concentration of PNVP-b-PNIPAM from 0.25 to 0.5 wt% in aqueous solution at 40°C, which is determined by DLS. 相似文献
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Summary: Novel, star‐shaped, amphiphilic block copolymers composed of fully degradable poly(caprolactone) were synthesized by sequential addition polymerization. In the first step, four‐arm macroinitiators were produced by ring‐opening polymerization of caprolactone by initiation with pentaerythritol. Then, block copolymers were synthesized by sequential addition of 4‐(2‐benzyloxyethyl)‐ε‐caprolactone to the four‐arm macroinitiators. Star‐shaped, amphiphilic block copolymers containing poly(caprolactone)‐block‐poly[4‐(2‐hydroxyethyl)caprolactone] segments were obtained by catalytic debenzylation.