A novel hydrophobically-modified polyelectrolyte for enhanced dewatering of clay suspension.
A novel hydrophobically-modified polyelectrolyte for enhanced dewatering of clay suspension.
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DOI：
10.1016/j.chemosphere.2017.12.009
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发表时间：
2018-03
期刊：
影响因子：
8.8
通讯作者：
S. Gumfekar;J. Soares
中科院分区：
文献类型：
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作者：
S. Gumfekar;J. Soares
研究了多功能聚（N-异丙基丙烯酰胺/丙烯酸/N-叔丁基丙烯酰胺）[p（NIPAM-AA-NTBA）]三元共聚物对油砂尾矿中主要组分高岭土沉降的影响。合成了一系列线性、未交联的p（NIPAM）、p（NIPAM/AA）和p（NIPAM/AA/NTBM）无规共聚物，其中所有单体单元沿聚合物主链沿着无规排列并通过共价键连接。三元共聚物，用作絮凝剂，表现出热敏性，阴离子性质，疏水缔合由于NIPAM，AA，和NTBM，分别。由于三元聚合物是热敏性的，在其低临界溶解温度（LCST）以上，其经历延伸到线圈状构象，即亲水性到疏水性转变。共聚单体NIPAM（高于LCST）和NTBM由于其疏水性而有助于将水从沉积物中排出，而AA促进高岭土颗粒的电荷中和。考察了NTBM的数均分子量、电荷密度和浓度对高岭土悬浮液沉降行为的影响。在50 °C下的沉降测试导致与在室温下的沉降速率相比显著更高的沉降速率。此外，在每个实验中回收的水的质量在其浊度方面进行测试。这些结果表明，这种新型三元聚合物可用于提高从含粘土的油砂尾矿中回收水。
This work investigates the effect of multifunctional poly (N-isopropyl acrylamide/acrylic acid/N-tert-butylacrylamide) [p(NIPAM-AA-NTBA)] ternary polymer on the sedimentation of kaolin clay – a major fraction of oil sands tailings. A series of linear, uncross-linked p(NIPAM), p(NIPAM/AA), and p(NIPAM/AA/NTBM) were synthesized as random copolymers, where all monomer units were randomly arranged along the polymer backbone and connected by covalent bonds. The ternary copolymer, used as a flocculant, exhibited thermo-sensitivity, anionic nature, and hydrophobic association due to NIPAM, AA, and NTBM, respectively. As the ternary polymer is thermosensitive, it undergoes extended to coil-like conformation, i.e. hydrophilic to hydrophobic transition, above its lower critical solution temperature (LCST). The comonomers NIPAM (above LCST) and NTBM help expel water out of sediments due to their hydrophobicity, while AA promotes charge neutralization of the kaolin clay particles. The effect of number average molecular weight, charge density, and concentration of NTBM on settling behavior of kaolin suspension was examined. Settling test at 50 °C resulted in significantly higher settling rates compared to that at room temperature. Further, the quality of water recovered in each experiment was tested in terms of its turbidity. These results indicate that this novel ternary polymer can be employed to enhance the recovery of water from oil sands tailings containing clays.