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1.
氯甲基化苯乙烯-二乙烯苯共聚体傅氏交联反应的研究   总被引:1,自引:1,他引:1  
氯甲基化苯乙烯-二乙烯苯共聚体在傅氏催化剂的存在下可以发生自身的傅氏交联反应从而制得一类新型吸附树脂,它们的物理化学性质和红外光谱分析证实了这类吸附树脂的结构。溶剂的性质,催化剂的种类和用量、反应温度和时间都对反应有明显的影响。这类吸附树脂具有比表面积高(1000—1300m~2/g)、孔度较大、孔分布较窄、比重大和机械强度高等特点。  相似文献   

2.
以壳聚糖为原料,利用Mannich反应原理,在壳聚糖分子的氨基上引入具有还原性能的亚磷酸基团,制备出新型还原性壳聚糖吸附剂RCA,并考察其对Cr(VI)的还原吸附效果。研究结果表明,当反应温度为80℃,戊二醛用量为45.0%,亚磷酸用量为30.0%,反应时间为2h时,制得的还原性壳聚糖吸附剂对Cr(VI)的还原吸附率为94.8%。此外,该吸附剂具有较强的耐酸碱能力和抗氧化能力。红外光谱分析和元素分析结果表明,壳聚糖分子上已成功引入亚磷酸基团。  相似文献   

3.
本文用邻硝基乙苯为溶剂,替代工业上常用的剧毒的硝基苯对氯甲基化聚苯乙烯(简称氯球)进行付氏后交联反应,详细地研究了反应条件如:反应温度、催化剂的种类及用量等对树脂孔结构性能的影响。并在最佳反应条件下进行放大实验,合成出的后交联树脂的比表面为817m2/g,孔容为0.727ml/g,平均孔径为10.9nm。  相似文献   

4.
工业二乙烯苯悬浮聚合制备的大孔树脂,在二氯乙烷溶剂中以无水三氯化铁为催化剂进行悬挂双键后交联反应,得到的后交联树脂的比表面积和孔容都有显著增加.低温氮气吸附/脱附等温线得到的孔径分布曲线证明初始共聚物PDT-55(polydivinylbenzene,toluene as porogen)和PDH-55(polydivinylbenzene,heptane andtoluene as porogen)经后交联反应,所形成的新孔以微孔为主.树脂对水溶液中苯酚和维生素B12(VB12)的静态吸附研究发现树脂经后交联后,对苯酚的吸附量有显著提高,但对VB12的吸附量增加不大,原因是分子尺寸较大的VB12无法进入由悬挂双键后交联反应所形成的微孔.树脂PDT-55pc对苯酚的吸附量大于商品树脂XAD-4;后交联前后树脂PDT-55、PDT-55pc(post-crosslinking of PDT-55)、PDH-55、PDH-55pc(post-crosslinking ofPDH-55)对VB12的吸附量均大于树脂XAD-4.在本研究的实验条件下,Langmiur和Freundlich吸附等温线方程能很好地拟合树脂对水溶液中苯酚和VB12的吸附,相关系数在0.99以上.静态吸附动力学实验结果表明后交联前后树脂对苯酚的吸附较VB12更容易达到吸附平衡.吸附动力学数据的拟合结果显示,McKay二级吸附动力学模型符合树脂对苯酚的吸附,而对VB12的吸附更符合Lagergren一级吸附动力学模型.  相似文献   

5.
Friedel-Crafts cycloalkylation of fluorene with 1,4-dichlorobutane has been studied in different conditions. This reaction allows to obtain the product of exhausting fluorene alkylation, hexadecahydrotetrabenzo[a,c,d,f]fluorene - perspective η5 ligand. The simplest zirconocene has been synthesized and its structure has been confirmed by X-ray diffraction analysis. The molecule of this compound possesses skewed conformation of metallocene fragment with the phenylene moiety of fluorenyl ligand oriented towards the front side of metallocene wedge.  相似文献   

6.
氯甲基化苯乙烯-二乙烯苯共聚物在傅氏催化剂存在下与取代酚(芳香胺)反应可以得到一些含取代酚基的离子交换树脂。它们的物理化学性质和红外光谱分析证实了该类树脂的结构。溶剂的性质、催化剂的种类、用量、反应温度、时间、取代酚(芳香胺)的取代基位置、聚合物的含氯量和孔结构都对反应和副反应有明显的影响。这类离子交换树脂在重金属分离、脱色,特别在维生素和抗菌素的选择吸附等方面,都有十分重要的意义。  相似文献   

7.
色谱流出峰的拖尾现象普遍存在于制备和大型色谱分离过程中,它直接影响分离的产率和回收率.本文提出采用色谱流出峰形的不对称偏差度来表征色谱流出峰的拖尾程度;并基于液相制备色谱分离过程FAD-SMT模型及吸附速率理论,通过计算机模拟,定量分析了吸附剂性能和操作参数对色谱流出峰形不对称性的影响。结果表明:不仅是吸附剂的热力学和动力学性能(包括吸附相平衡关系、液固两相间的传质阻力);而且柱的设计和吸附剂的装填状况(包括轴向扩散系数),以及色谱分离的操作条件(进料时间、浓度和流速等)都直接影响色谱流出峰形的不对称性。随着吸附相平衡等温线的非线性程度增大,或者总传质系数的减小,色谱流出峰形的不对称偏差度明显增大;吸附剂吸附容量的减小也将引起色谱流出峰形的不对称偏差度的增加;色谱流出峰形的不对称偏差度与进科体积、浓度和流体线速,以及轴向扩散系数的增大成正比。  相似文献   

8.
具有高比表面积的极性吸附树脂的合成和性能研究   总被引:3,自引:1,他引:3  
本文从树脂物理结构和化学结构着手,通过改变交联度,致孔剂用量,种类以及引入适量功能基因,分别合成了一系列具有高比表面积和极性的大孔吸附树脂,研究了它们对工业废水中β-萘碘酸的吸附-脱附性能.  相似文献   

9.
在四氢呋喃、环己酮等溶液中实现了聚氯乙烯(PVC)与聚苯乙烯(PS)的Friedel-Crafts接枝反应,考察了加热方式、反应温度、催化剂种类、催化剂用量对接枝反应的影响,通过FTIR表征了PVC-g-PS接枝物的结构,探讨了反应的机理和特点.研究发现,油浴加热和微波辐照都能使PVC和PS发生接枝反应,但微波辐照效果更好,油浴加热,接枝率仅0.27%,而微波辐照接枝率高达23%;油浴加热时产物少且多为间位,微波辐照时产物多且多为对位和邻位.无水AlCl3、无水FeCl3、无水SnCl4皆对PVC与PS之间的Friedel-Crafts反应具有催化活性,其中无水AlCl3的催化活性最高,其最佳用量为质量分数3%,此时,接枝率达到29%.当无水AlCl3过高时,PVC降解,产生双键,接枝率下降.表明微波辐照是实现PVC与PS之间Friedel-Crafts接枝反应的有效途径.  相似文献   

10.
R. Leboda 《Chromatographia》1981,14(9):524-528
Summary The surface properties of complex adsorbents prepared through the pyrolysis of dichloromethane on the surface of silica gel were investigated. The reaction was carried out in a specially constructed reactor at 400–500°C. The construction and performance of the reactor are described. The modification of the silica gel surface by pyrogenic carbon results in its chemical but not energetical homogeneity. Such adsorbents usually show strong adsorptive properties which limits their use in chromatography. A simple method of homogenizing the porous structure and energetic properties of the adsorptive centers of such adsorbents is presented. The method consists of an additional pyrolysis of an alcohol or other substances on the surface of the carbon-silica adsorbent. Such reactions were carried out under both static and dynamic conditions. The properties of the modified adsorbent depend on the reaction conditions and on the type of the additionally pyrolysed substance.  相似文献   

11.
Several physical properties of various silicic derivatives are examined in order to elucidate an interference with fluoride during codistillation of hexafluorosilicic acid with superheated steam.The stated interference cannot be explained by the granulometry or by the specific surface area of the interfering derivatives but their porous structure: a nonporous adsorbent (silica) does not interfere; a porous adsorbent (silicic acid and silica gel) is liable to interfere when its pores reach a definite size, approximately a diameter of 50 Å.The occurrence of imprisonment of some fluoride anions in the pores of the interfering silicic derivatives is suggested.  相似文献   

12.
In order to study the mechanism of the formation of maeroporous copolymer, the overall reaction kinetics, phase separation and gelation of the S/EGDM in the presence of inert solvents and the physical properties of the eopolymer were investigated and compared with the corresponding system of S/DVB and S/DVB/MMA. The formation of the network structure of the macroreticular polymer was studied and a model of the mechanism suggested.  相似文献   

13.
本文以异氰尿酸三烯丙酯 TAIC)为交联剂,醋酸乙烯酯(VAC)为单体合成的共聚物(VT),经皂化和活化后,固载上DNA,即得含DNA配体的VT吸附剂。测定了各产物的物理性能,表面形态,红外光谱和血液相容性。实验结果表明:聚合物具有较大平均孔径,皂化后亲水性增强,随活化而使比表面积增大,孔分布趋于均匀,固载DNA的能力高,致使最后产物表面DNA覆盖致密程度高,考察其血液相容性良好,对血小板粘附率约为10%,对白细胞无破坏,每克吸附剂清除抗-DNA蛋白2小时可达60%以上。  相似文献   

14.
含DNA配体的VT吸附剂结构及其血液相容性研究   总被引:4,自引:0,他引:4  
 本文以异氰尿酸三烯丙酯 TAIC)为交联剂,醋酸乙烯酯(VAC)为单体合成的共聚物(VT),经皂化和活化后,固载上DNA,即得含DNA配体的VT吸附剂。测定了各产物的物理性能,表面形态,红外光谱和血液相容性。实验结果表明:聚合物具有较大平均孔径,皂化后亲水性增强,随活化而使比表面积增大,孔分布趋于均匀,固载DNA的能力高,致使最后产物表面DNA覆盖致密程度高,考察其血液相容性良好,对血小板粘附率约为10%,对白细胞无破坏,每克吸附剂清除抗-DNA蛋白2小时可达60%以上。  相似文献   

15.
本工作制备了以大孔交联聚苯乙烯为第一网络,以由环硫氯丙烷与多乙烯多胶反应而形成的交联聚合物为第二网络的互贯型流基胺树脂,并测定了其孔结构.该互贯型树脂与相应的凝胶型树脂相比,在酸性介质中膨胀程度小得多,而对Ag~+、Au~+3n的吸附性能更好.对Ag~+、Au~3+的吸附容量分别可达432mgAg~+/g和553mgAu~3+/g.对Au~3+的吸附率大于99%.  相似文献   

16.
Ag nanoparticles (AgNPs) were used as adsorbent to remove trace iodide from acetic acid. Under identical conditions, AgNPs adsorbent with 0.5 wt % Ag has the same performance as commercial adsorbent with 10 wt % Ag+. In addition, Ag loss of AgNPs adsorbent is remarkably lower than that of commercial adsorbent. The Ag content in AgNPs adsorbent affects its adsorption performance, and the optimal content is 1.0 wt %. Saturated AgNPs adsorbent can be regenerated by hydrogen reduction and reused with satisfying performance. The properties of AgNPs adsorbent are based on surface effect of nanoparticles, differing from commercial Ag+ type adsorbents. In a word, AgNPs adsorbent is of high efficiency, low Ag loss and easy recycling, thus making it ??green adsorbent?? for removing iodide from acetic acid.  相似文献   

17.
本文研究了在染印法空白片的各种坚膜条件下媒染层的物理机械性能和染印性能,包括媒染层的断裂强度、空白片的膨胀度、染色密度和线格清晰度。铬矾坚膜的效果用媒染层中铬的含量和媒染层经水萃取后所得交联物含量来表示。在此基础上计算出用铬矾坚膜的媒染层的交联密度。为排除空白片中乳剂层的干扰,采用了单独处理媒染层的方法。得到了在本实验中获得空白片最佳清晰度和最佳物理机械性能的条件,并对媒染层中主要物质分子间的相互关系进行了探讨。  相似文献   

18.
T_g以下温度退火对无规聚苯乙烯性能的影响   总被引:2,自引:0,他引:2  
用调幅式DSC等新技术研究了物理老化对无规聚苯乙烯多种性能的影响.随着老化时间的延长,试样的玻璃化转变温度、热焓松弛、峰温、峰高和热焓提高;老化使材料的初始模量,屈服应力和断裂强度都有不同程度的提高;使样品的溶剂扩散速率降低,但对样品的密度和声传播速度几乎没有影响.以上这些结果可从物理老化引起试样中凝聚缠结增加的观点来进行解释.  相似文献   

19.
Ferrocenecarbothioamide (1) and its N-ethoxycarbonyl derivative (2) were synthesised by a Friedel-Crafts type reaction of ferrocene with potassium thiocyanate and ethoxycarbonyl isothiocyanate, respectively, in a strongly acidic medium. The X-ray structure of 1 was determined and shows conjugation between the ferrocene moiety and the thioamido group. Compound 1 reacts with chloroacetylferrocene affording 2,4-diferrocenylthiazole, whose structure was determined by X-ray diffraction and electronic properties studied by cyclic voltammetry.  相似文献   

20.
The development of adsorptive materials continues to be an important area of research for removal of heavy metal ions from waste water. The adsorption capacity can be modulated by both physical and chemical modification of the adsorbent. Herein, we combine the unique properties of polyhedral oligomeric silsesquioxane (POSS) and organocyclophosphazene as the building units to synthesize a hybrid porous material, abbreviated as PN‐POSS. The synthetic method follows a Heck reaction between hexa(4‐bromophenoxy)cyclotriphosphazene and octavinylsilsesquioxane (OVS). The Brunauer–Emmett–Teller (BET) analysis shows that the material possesses micro‐ and mesopores of 1.5 and 3.8 nm size and a surface area on the order of 500 m2 g?1. These attributes in combination with the donor ability of the phosphazene units qualify the material for high adsorption of Pb2+, Hg2+ and Cu2+ ions with maximal adsorption capacities on the order of 1326, 1927 and 2654 mg g?1, respectively. The adsorbent exhibits a good regeneration performance and can be effectively used for water treatment.  相似文献   

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