Chemical modification of monolithic poly(styrene-divinylbenzene) PolyHIPE(R) materials
Chemical modification of monolithic poly(styrene-divinylbenzene) PolyHIPE(R) materials
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DOI：
10.1039/jm9960600719
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发表时间：
1996-05-01
影响因子：
--
通讯作者：
Kurosu, H
中科院分区：
文献类型：
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作者：
Cameron, NR;Sherrington, DC;Kurosu, H
高孔聚（苯乙烯/DVB） PolyHIPE(R)整体样品经历了一系列亲电芳取代反应，即磺化、硝化和溴化。在整个大型聚合物结构中，寻求温和的疏水试剂和均匀的反应条件，以实现均匀的化学改性，达到合理的取代程度。因此，用月桂醇硫酸盐在环己烷中进行磺化，用四丁基硝酸铵-三氟乙酸酐（TBAN-TFAA）在二氯甲烷中进行硝化，用溴-氯化锡在二氯甲烷中进行溴化。平均磺化程度为2.4 mmol g(-1)，从表面到中心的磺酸含量下降约1 mmol g（-1）。硝化作用发生的程度较小，在表面和中心之间观察到类似的取代差异。PolyHIPE(R)单片样品被溴化到3.6 mmol g（-1）的程度，而且，这在整个底物上是均匀的。每种反应程度的差异可以通过考虑溶剂的性质、试剂的极性以及整个反应过程中试剂与聚合物基体之间的相容性等因素来解释。
Monolithic samples of highly porous poly(styrene/DVB) PolyHIPE(R) have undergone a number of electrophilic aromatic substitution reactions, namely sulfonation, nitration and bromination. Mild, hydrophobic reagents and homogeneous reaction conditions were sought in an effort to achieve uniform chemical modification, to a reasonable degree of substitution, throughout the large polymeric structures. Thus, sulfonation was Carried out with lauroyl sulfate in cyclohexane, nitration with tetrabutylammonium nitrate-trifluoroacetic anhydride (TBAN-TFAA) in dichloromethane and bromination with bromine-stannic chloride in dichloromethane. An average degree of sulfonation of 2.4 mmol g(-1) was achieved, with a drop in sulfonic acid content of approximately 1 mmol g(-1) from surface to centre. Nitration occurred to a lesser extent, with similar differences in substitution between surface and centre being observed. PolyHIPE(R) monolithic samples were brominated to an extent of 3.6 mmol g(-1) furthermore, this was uniform across the entire substrate. The differences in extent of each reaction are explained by consideration of such factors as the nature of the solvent, polarity of the reagents and compatibility between the reagents and the polymer matrix throughout the reactions.