Herein, we report the synthesis of a new thermally stable magnetic polyurethane nanocomposite (MPUNc) (14) containing azobenzene moiety and β-cyclodextrin (β-CD) and its application in removing some organic pollutants from water. First, 4,4′-azodibenzene dicarboxylic acid (2) was synthesized and then it was converted to 4,4′-azodibenzene diacyl azide (3). MPUNc (14) was synthesized by grafting magnetic nanoparticles (MNPs) (11) onto β-CD-AzoPU (10). The properties of the MPUNc (14) were characterized by FTIR, ¹H NMR, XRD, SEM, EDX, VSM, and TGA. By adding MPUNc (14) to PVA, the stress–strain curves of the resulting blend showed a ductile fracture due to the digressing toughness of PVA. The magnetic saturation (Ms) values demonstrated that the magnetic property of Fe₃O₄ was reduced when coated by SiO₂. The TGA thermogram of MPUNc (14) showed a 10% weight loss below 300 °C. In addition, the weight loss of about 33% between 350 and 750 °C was due to the chemical decomposition of β-CD-AzoPU (10) and EPO moieties. Thus, the results showed that the grafted β-CD-AzoPUs (10) to MNPs (11) had a density of about 18%. The MPUNc (14) was used as a new absorbent to remove 4-chlorophenol (4-CP) and 4-nitrophenol (4-NP) from water. Besides, the effects of pH, time, temperature, and the absorbent dosage on the adsorption ability were studied. The results showed that the pH and the adsorbent dosage had a key role in removing 94% of the 4-NP and 91.3% of 4-CP at the optimized pH of 3 using 50 mg of the sorbent.

中文翻译：

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新型磁性β-环糊精聚氨酯纳米复合材料用于去除废水中的有机污染物

本文中，我们报道了一种新型的热稳定的磁性聚氨酯纳米复合材料（MPUNc）（14）的合成，该复合材料包含偶氮苯部分和β-环糊精（β-CD），并在去除水中某些有机污染物中具有应用。首先，合成4,4'-偶氮二苯二羧酸（2），然后将其转化为4,4'-偶氮二苯二酰基叠氮化物（3）。通过将磁性纳米颗粒（MNP）（11）接枝到β-CD-AzoPU（10）上来合成MPUNc（14）。通过FTIR，¹ H NMR，XRD，SEM，EDX，VSM和TGA对MPUNc（14）的性质进行了表征。通过添加MPUNc（14）对PVA而言，由于PVA的分散韧性，所得混合物的应力-应变曲线显示出韧性断裂。磁饱和（Ms）值表明，当用SiO ₂涂覆时，Fe ₃ O ₄的磁性能降低。MPUNc（14）的TGA热分析图显示，在300°C以下，重量减轻了10％。另外，在350至750°C之间重量减少约33％是由于β-CD-AzoPU（10）和EPO部分的化学分解。因此，结果表明，将β-CD-AzoPU（10）嫁接到MNP （11）上的密度约为18％。MPUNc（14）作为一种新型吸收剂，可从水中去除4-氯苯酚（4-CP）和4-硝基苯酚（4-NP）。此外，研究了pH，时间，温度和吸收剂量对吸附能力的影响。结果表明，在使用50 mg吸附剂的最适pH值为3的条件下，pH和吸附剂剂量对去除94％的4-NP和91.3％的4-CP具有关键作用。