Preparation of poly(ε-caprolactone)@attapulgite nanocomposites via a combination of controlled ring-opening polymerization and click chemistry

In this work, by a combination of controlled ring-opening polymerization ( CROP) and click chemistry, we report a facile and useful method to synthesize linear poly(epsilon-caprolactone)@attapulgite nanocomposites with well-defined structures. For this, first, the chlorine-terminated attapulgite was prepared by the self-assembly of 3-chloropropyltrimethoxysilane from the surfaces of attapulgite. And then, the terminal chlorines of modified attapulgite were substituted with azido groups. As the second step, linear propargyl-terminated poly(epsilon-caprolactone) (PCLs) with different molecular weights were synthesized by the CROP of epsilon-CL monomer in toluene with stannous octoate as a catalyst and propargyl alcohol as an initiator. The structural characteristics of the obtained linear PCLs have been determined by H-1 NMR and gel permeation chromatography analysis. Finally, the azido-terminated attapulgite was reacted with propargyl-terminated PCLs via the click reaction.