Song Menglu, Yang Xiangui, Wang Gongying
Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences Chengdu 610041 China
National Engineering Laboratory & Technology, University of Chinese Academy of Sciences Beijing 101408 China.
RSC Adv. 2018 Oct 12;8(61):35014-35022. doi: 10.1039/c8ra07141a. eCollection 2018 Oct 10.
γ-AlO loaded with potassium nitrate (KNO/AlO) catalysts were prepared, characterized and employed as a type of heterogenous solid base catalyst in the synthesis of polycarbonate (1,4-butane carbonate)-diol (PBC-OH) the transesterification of dimethyl carbonate (DMC) and 1,4-butanediol (BD). The relationship between physicochemical properties and catalytic performance for KNO/AlO in this transesterification reaction was investigated using various techniques. The results demonstrated that the performance of KNO/AlO catalysts was highly influenced by basic site amount and strength. The medium and strong basic sites were beneficial for this reaction. The catalyst with a KNO loading of 35% and a calcination temperature of 700 °C exhibited the best catalytic activity due to its highest basic site amount and appropriate base strength. The highest BD conversion and PBC-OH yield of 80.2% and 68.4% were obtained under optimal reaction conditions. Also, this solid base catalyst was successfully employed in the synthesis of copolycarbonate diols from DMC and two different diols. Different scanning calorimetry results indicated that the thermal properties of the copolycarbonate diols can be adjusted by regulating the average segment lengths, and copolymer composition structure.
制备了负载硝酸钾（KNO₃/Al₂O₃）的γ -Al₂O₃催化剂，对其进行了表征，并将其用作一种非均相固体碱催化剂，用于通过碳酸二甲酯（DMC）与1,4 -丁二醇（BD）的酯交换反应合成聚碳酸酯（1,4 -丁二醇碳酸酯）二醇（PBC - OH）。使用各种技术研究了KNO₃/Al₂O₃在该酯交换反应中的物理化学性质与催化性能之间的关系。结果表明，KNO₃/Al₂O₃催化剂的性能受碱性位点数量和强度的影响很大。中等强度和强碱性位点对该反应有利。负载量为35%且煅烧温度为700℃的催化剂由于其最高的碱性位点数量和合适的碱强度而表现出最佳的催化活性。在最佳反应条件下，BD的最高转化率和PBC - OH的产率分别达到80.2%和68.4%。此外，这种固体碱催化剂成功用于由DMC和两种不同二醇合成共聚碳酸酯二醇。差示扫描量热法结果表明，共聚碳酸酯二醇的热性能可以通过调节平均链段长度和共聚物组成结构来调节。
