One-Pot Synthesis and Evaluation of Properties of Optically Active Poly(imide–urethane)s
作者:Hojjat Toiserkani、Marziyeh Rafiaee
DOI:10.1246/bcsj.20120281
日期:2013.2.15
A new diacylazide 2 bearing two preformed imide rings and (S)-valine was prepared in three steps, starting from the reaction of 4,4′-carbonyldiphthalic anhydride with (S)-valine in refluxing glacial acetic acid, followed by treating 4,4′-carbonylbis[(S)-2′′-phthalimidovaline] (1) with ethyl chloroformate in the presence of triethylamine, and subsequently by a nucleophilic reaction with sodium azide. A novel family of optically active poly(imide–urethane)s (PIUs) with moderate inherent viscosities in the range 0.25–0.44 dL g−1 were prepared from diacylazide 2 and various aromatic diols in dry toluene under refluxing in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO, triethylenediamine) as a catalyst. The polycondensation reaction readily proceeded in desirable yields as one-pot reactions starting from 2 without separate synthesis of the corresponding diisocyanate. All of the resulting polymers were thoroughly characterized by spectroscopic methods and specific rotation. The PIUs exhibited an excellent solubility in a variety of polar solvents. Experimental results indicated that all the PIUs had glass-transition temperature between 179 and 218 °C, the decomposition temperature at 10% weight loss between 201 and 223 °C under nitrogen.
4,4'-羰基二邻苯二甲酸酐与(S)-缬氨酸在回流冰醋酸中反应,然后处理4,分三步制备了带有两个预先形成的酰亚胺环和(S)-缬氨酸的新二酰基叠氮化物2, 4'-羰基双[(S)-2''-邻苯二甲酰亚胺缬氨酸] (1) 在三乙胺存在下与氯甲酸乙酯反应,随后与叠氮化钠发生亲核反应。由二酰基叠氮化物 2 和各种芳香族二醇在无水甲苯中在 1 存在下回流制备出一类新型光学活性聚(酰亚胺-氨基甲酸酯)(PIU),其特性粘度在 0.25-0.44 dL g−1 范围内。 4-二氮杂双环[2.2.2]辛烷(DABCO,三亚乙基二胺)作为催化剂。作为从2开始的一锅反应,缩聚反应容易以期望的产率进行,无需单独合成相应的二异氰酸酯。所有所得聚合物均通过光谱方法和比旋光度进行了彻底表征。 PIU 在多种极性溶剂中表现出优异的溶解度。实验结果表明,所有PIU的玻璃化转变温度在179~218℃之间,在氮气下失重10%时的分解温度在201~223℃之间。