End-Functionalized Polylactides Using a Calcium-Based Precatalyst: Synthesis and Insights by Mass Spectrometry

A simple and convenient method for the synthesis of end functionalized polylactides (PLAs) under mild conditions by ring opening polymerization (ROP) in the absence of potentially toxic catalysts is described. Various alcohols were used as initiators in combination with Ca[N(SiMe3)(2)](2)(THF)(2) as the precatalyst in THF at room temperature. Tailored end functionalities were obtained in a controlled fashion. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF-MS) and electrospray ionization quadrupole time of flight mass spectrometry (ESI-Q-ToF-MS) analysis were performed to investigate the end groups. The results confirmed that the end group fidelity was maintained in the isolated PLAs. (C) 2015 Wiley Periodicals, Inc.