关键词: 开环聚合反应, 聚乳酸, 沸石咪唑酯骨架-67, 非均相催化

Abstract:

To explore the metal effecting in structure of zeolitic imidazolate frameworks(ZIFs) influenced to its catalytic activity, we have synthesized ZIF-8, Zn/Co-ZIF and ZIF-67 by room temperature method and applied them as catalysts for the bulk ring-opening polymerization of L-lactide. Under the same reaction condition, ZIF-67 shows the highest catalytic activity. Compared to 2-methylimidazolate(linker) as a catalyst under the same reaction condition, the poly(lactic acid) obtained with ZIF-67 has highly isotactic structure. In addition, the matrix assisted laser desorption ionization-time of flight(MALDI-TOF) mass spectrum indicate that the poly(lactic acid) obtained with ZIF-67 has an almost linear structure. ZIF-67 can be reused for three times without significantly loss of catalytic activity.

Key words: ring-opening polymerization, poly(lactic acid), zeolitic imidazolate framework-67, heterogeneous catalysis