Isomeric and structural effects in polymer cononsolvent systems
Isomeric and structural effects in polymer cononsolvent systems
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DOI：
10.1016/j.polymer.2019.03.011
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发表时间：
2019-03
期刊：
影响因子：
4.6
通讯作者：
Xiaolong Lang;Erin X. Xu;Yuan Wei;L. Walters;Michael J. A. Hore
中科院分区：
文献类型：
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作者：
Xiaolong Lang;Erin X. Xu;Yuan Wei;L. Walters;Michael J. A. Hore
温敏性聚(N-异丙基丙烯酰胺)(PNIPAM)有许多类似物，在水和酒精的混合物中表现出溶解行为。溶解不良的特征是聚合物的良好溶剂的组合会导致溶解度降低。本工作研究了端基疏水性不同的线型PNIPAM、四臂(4f)星型PNIPAM和线型聚(N-正丙基丙烯酰胺)(PNnPAM)在水和丙醇混合溶剂中的溶解行为。通过RAFT聚合合成聚合物，然后用一锅氨解/硫醇-烯化学对聚合物进行官能化。用比浊法和动态光散射法(DLS)测定了临界溶解温度(TC)，研究了该体系的溶解行为。测量结果表明，溶剂和正烷基丙烯酰胺单体疏水区的大小和形状都影响Tc值和相变行为。这些发现提出了赋予软材料系统多响应性的方法。
Thermoresponsive poly (N-isopropylacrylamide) (PNIPAM) has many analogs that exhibit cononsolvency behavior in mixtures of water and an alcohol. Cononsolvency is characterized by a combination of good solvents for a polymer that results in decreased solubility. In this work, the cononsolvency behavior of linear PNIPAM, four-arm (4f) star PNIPAM, and linear poly(N-n-propylacrylamide) (PNnPAM), with terminal groups that vary in hydrophobicity, were investigated in mixtures of water and propanol. Polymers were synthesized by RAFT polymerization and subsequently functionalized with one pot aminolysis/thiol-ene chemistry. Turbidimetry measurements and dynamic light scattering (DLS) were used to study the cononsolvency behavior by determining the critical solution temperature (Tc). The measurements show that the size and shape of the hydrophobic region of both the solvent and n-alkyl acrylamide monomer affectTcand the phase transition behavior. The findings suggest methods to impart multiresponsiveness to soft material systems.