二步法制备CO2响应性DAAM-co-VAm温敏共聚物及其在水溶液中的相变行为

Synthesis of temperature sensitive polymer with CO2 responsiveness by two step method and phase transition behaviors in aqueous solutions

摘要:

以双丙酮丙烯酰胺（DAAM）和N-乙烯基甲酰胺（NVF）为单体，以过硫酸铵和亚硫酸氢钠为引发剂进行水溶液自由基聚合，合成了共聚物P(DAAM-co-NVF)，并在碱性条件下水解制得了聚合物P(DAAM-co-VAm)。采用傅立叶红外光谱（FTIR）、核磁共振氢谱（1H-NMR）、凝胶渗透色谱（GPC）和热失重分析（TGA）对合成的产物进行了表征分析，同时以紫外可见光谱（UV-Vis）和差示扫描量热仪（DSC）对P(DAAM-co-NVF)和P(DAAM-co-VAm)水溶液的相转变行为进行了研究。结果表明，所制备的聚合物P(DAAM-co-NVF)和P(DAAM-co-VAm)具有可调控的低临界溶解温度（LCST），通过改变组成和聚合物溶液的浓度，可以调控P(DAAM-co-NVF)和P(DAAM-co-VAm)的LCST。而且，在P(DAAM-co-VAm)水溶液中通入CO2可以调控聚合物的LCST。P(DAAM-co-VAm)水溶液的LCST具有可逆的CO2/N2开关响应性能。

Abstract:

P(diacetone acrylamide-co-vinylamine) (P(DAAM-co-VAm)) was obtained from the hydrolization of P(diacetone acrylamide-co-N-vinylformamide) (P(DAAM-co-NVF)) which was synthesized by solution free radical polymerization of diacetone acrylamide (DAAM) and N-vinylformamide (NVF), using ammonium persulfate and sodium hydrogen sulfite as initiator. Fourier transform infrared spectrometer (FTIR), nuclear magnetic resonance spectroscopy (1H-NMR), gel permeation chromatography (GPC) and thermal gravimetry (TG) have applied to character the structure, composition and molecular weight of the resultant polymers. The phase transition behavior of the resultant P(DAAM-co-NVF) and P(DAAM-co-VAm) was evaluated by UV-Vis spectroscopy and differential scanning calorimeter (DCS). Experimental results showed that LCST of P(DAAM-co-NVF) and P(DAAM-co-VAm) solutions could be controlled by changing the composition of the polymer and concentration of the solution. Moreover, LCST of P(DAAM-co-VAm) solution could be tuned by bubbling CO2 into the system. LCST of P(DAAM-co-VAm) solution has reversible response to CO2 and N2 switching.