[Hmim]HSO_4离子液体中微波合成聚天冬氨酸方法研究

Microwave synthesis of polyaspartic acid in [Hmim]HSO_4 ionic liquid

以L-天冬氨酸为原料,在[Hmim]HSO4离子液体中微波合成聚天冬氨酸(PASP)。研究了在该反应体系中n(L-Asp):n(L-Asp+[Hmim]HSO4)、微波功率、反应时间对聚天冬氨酸收率的影响,利用红外光谱和核磁共振对产品结构进行了表征。结果表明:合成产品具有酰亚胺和羰基结构。聚合的最佳条件为:n(L-Asp)∶n(L-Asp+[Hmim]HSO4)=0.45∶1、微波功率320 W、聚合时间260 s,在此条件下,收率可达96.1%。该方法产品收率比传统液相聚合法提高了11.5%。分析认为Brφnsted酸性离子液体能够促进L-Asp生成碳正离子,加速质子转移生成酰胺键。

Polyaspartic acid （PASP）has been synthesized in the medium of [ Hmim ] HSO4 ionic liquid with microwave by using L-aspartic acid as raw material. The influences of n （L-Asp）：n （L-Asp ＋[Hmim]HSO4）,microwave power and polymerization time on PASP yield coefficient are studied. The product structure is analyzed with infrared spectrum and ^1HNMR spectroscopy. The results show that the obtained product has the configuration of imide and carbonyl. The optimal conditions of polymeric reaction are as follows：n（L-Asp）：n（L-Asp ＋ [Hmim]HSO4） =0.45：1, microwave power is 320 W and reaction time 260 s. Under the above conditions, the yield coefficient reaches 96.1% and it has increased by 11.5%, compared to the traditional liquid-phase polymerization process. It is considered that Brφnsted acid ionic liquid can expedite L-Asp to generate carboniumion, speed up the proton translocation, and create amido link.