Mavronasou Katerina, Zamboulis Alexandra, Klonos Panagiotis, Kyritsis Apostolos, Bikiaris Dimitrios N, Papadakis Raffaello, Deligkiozi Ioanna
Creative Nano PC, 4 Leventi Street, Peristeri, 12132 Athens, Greece.
Laboratory of Polymer Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
Polymers (Basel). 2022 Feb 19;14(4):804. doi: 10.3390/polym14040804.
A series of N-methyl quaternized derivatives of poly(4-vinylpyridine) (PVP) were synthesized in high yields with different degrees of quaternization, obtained by varying the methyl iodide molar ratio and affording products with unexplored optical and solvation properties. The impact of quaternization on the physicochemical properties of the copolymers, and notably the solvation properties, was further studied. The structure of the synthesized polymers and the quaternization degrees were determined by infrared and nuclear magnetic spectroscopies, while their thermal characteristics were studied by differential scanning calorimetry and their thermal stability and degradation by thermogravimetric analysis (TG-DTA). Attention was given to their optical properties, where UV-Vis and diffuse reflectance spectroscopy (DRS) measurements were carried out. The optical band gap of the polymers was calculated and correlated with the degree of quaternization. The study was further orientated towards the solvation properties of the polymers in binary solvent mixtures that strongly depend on the degree of quaternization, enabling a better understanding of the key polymer (solute)-solvent interactions. The assessment of the underlying solvation phenomena was performed in a system of different ratios of DMSO/HO and the solvatochromic indicator used was Reichardt's dye. Solvent polarity parameters have a significant effect on the visible spectra of the nitrogen quaternization of PVP studied in this work and a detailed path towards this assessment is presented.
通过改变碘甲烷的摩尔比，以高收率合成了一系列不同季铵化程度的聚（4-乙烯基吡啶）（PVP）的N-甲基季铵化衍生物，得到了具有未探索的光学和溶剂化性质的产物。进一步研究了季铵化对共聚物物理化学性质，特别是溶剂化性质的影响。通过红外光谱和核磁共振光谱确定了合成聚合物的结构和季铵化程度，同时通过差示扫描量热法研究了它们的热特性，并通过热重分析（TG-DTA）研究了它们的热稳定性和降解情况。关注了它们的光学性质，进行了紫外可见光谱和漫反射光谱（DRS）测量。计算了聚合物的光学带隙，并将其与季铵化程度相关联。该研究进一步针对聚合物在二元溶剂混合物中的溶剂化性质，这种性质强烈依赖于季铵化程度，从而能够更好地理解关键的聚合物（溶质）-溶剂相互作用。在不同比例的二甲基亚砜/水体系中对潜在的溶剂化现象进行了评估，使用的溶剂显色指示剂是赖卡特染料。溶剂极性参数对本研究中所研究的PVP氮季铵化的可见光谱有显著影响，并给出了实现这种评估的详细途径。
